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RE0F05A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Jatco CVT RE0F05A (also known as NCVT) is commonly installed on small cars with engines having the capacity up to 1500 cm3. In terms of control, this transmission is fully hydraulic, i.e it includes the block of hydraulic valves like in standard automatic transmissions, but the transmission operation is performed thanks to movement of the main pulley.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	135	3,2	3	D Fluid N-CVT

The main problem of this transmission lies in increase or decrease of the gear ratio, like an emergency mode (2-nd gear). The repair of this transmission should be performed by professionals on a special bench.

BTR M78LE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

6-speed automatic transmission DSI-6 \ M78LE (M96) was developed in 2008 by specialists of former BTR bureau with a new Chinese owner Geely under a new brand DSI. It is more advanced modification of 6-speed automatic transmission with a longitudinal positioning for 2-liter engines SsangYong Actyon.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD/AWD		9,5	4,5	ATF 3292

Technical issues and repair guidelines

In many cases vibrations from the worn-out torque converter lead to the damage of the oil pump bearing. The pump with the planetary gear is considered to be a soft spot of 6-speed М78. The planetary gear is damaged by increased torque and vibrations from the torque converter. With regard to electrics solenoids-electric controllers, shifters and solenoids-electric controllers M78 are replaced in this transmission.

How to repair this transmission (Videos)

TCC Shudder Repair

Solenoid valve test M78

BTR M74LE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission BTR M74LE with a longitudinal positioning for RWD vehicles was designed in 1988 by BTR company on commission from a Korean automaker SsangYong for its flagship SUV Korando. In 1989, this RWD transmission was launched in mass-production. In most cases, the M74LE transmission was mated with 2-3-liter engines and found application in RWD SsangYong models - Rexton, Actyon, Korando etc. The 6-speed automatic transmission DSI-6 \ M78LE (M96) was developed in 2008 by specialists of former BTR bureau with a new Chinese owner Geely under a new brand DSI. It is more advanced modification of the 6-speed automatic transmission with a longitudinal positioning paired with the 2-liter engines SsangYong Actyon.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		9	3,5	BTR M74LE

Technical issues and repair guidelines

In most cases, М74 and М78 transmission models require ATF change and filter replacement during the overhaul. In addition, specialists usually order the pan gasket. For reassembly of М78 (and М74) specialists order the repair kit of gaskets and seals /Overhaul kit and a complete kit of friction components. Brake bands (Intermediate (Direct, High/ Reverse) ) are also considered to be spare parts for this transmission. The rear brake band is replaced in case of burnt fluid and uneven wear-out and the band clearance, in order to exclude kicks in the process of gears shifting.

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme

BTR М11 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission BTR М11 with east-west positioning was installed on New Actyon (Corando С) in 2010. This transmission was paired with the 2-liter diesel engine having the torque up to 380 Nm. In 2012, after implementation of some changes the М11 unit was modified with introduction of different improvements. This transmission is intended for FWD as well as AWD SUVs.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/AWD	380	7,5	4	SsangYong 0578-244021

Technical issues and repair guidelines

Typical repair procedures for this transmission include reassembly and replacement of rings, seals, and gaskets (Overhaul kit). In many cases, the whole set of friction components is replaced by repair specialists. The wear-out of frictions leads to clearance increase in clutch packages. Abnormal (increased) clearances in clutch packages (and braking drums) lead to jolts and increase the risk of vibrations under load. Replacement of the brake band with a servo piston is performed in case of vibrations detection in the B1 (555) Drum or shifting with the kick or there is uneven wear-out of servo piston and brake clearance.

The necessity to replace of the rear planetary gear in the М11 transmission lies in overloading caused by aggressive driving and neglect of the automatic transmission maintenance services. The oil pump is one of the most popular issues in the M11 unit. This pump breaks down in situations when the overhaul of the transmission and its torque converter is delayed for a long time, consequently leading to extreme vibrations in the torque converter, complicated by contaminated fluid. The piston of the В2 brake package is frequently replaced in this transmission. This piston gets out of order because of overheating and a long-term operation with vibrations. Solenoids are included in the list of commonly replaced spare parts. The M11 transmission design includes 6 VBS solenoids with different holders.

How to repair this transmission (Videos)

New Actyon BTR M11

6F24 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6F24 transmission model replaced not very successful M11 model in 2013. This transmission has been installed on Dodge Dart, Jeep Compass, Patriot MK since 2013. In terms of design, this transmission is a copy of the A6MF transmission. For integration of this transmission with SsangYong engines, engineers had to modify electrical part of this transmission, including solenoids and the software.

Technical issues and repair guidelines

This transmission has the same typical problems as A6MF1 and A6MF2 transmissions.

The ATF change should be performed after 80 travelling thousand kilometers, but the fluid condition should be controlled every 20 thousand kilometers. In case of aggressive driving manner it may be necessary to change the fluid earlier. The filter for the 6F24 unit is replaced only with removal of the cover and repair/cleaning of the valve body. Specialists recommend to clean the valve body and replace the filter after 120-140 thousand kilometers (when detecting first signs of improper gears shifting) without waiting for wear-out of solenoids. Transmission specialists repair the torque converter if the fluid becomes very hot and gets rapidly contaminated.

Engineers of SsangYong adjusted the valve body operation for 6F24 not very carefully, therefore the torque converter slipping (as in Hyundai) and aggressive driving behavior may lead to the lock-up clutch damage by the torque converter by the end of the car warranty period.

How to repair this transmission (Videos)

A6MF1 4WD Teardown

A6MF1 TRANSMISSION TEAR DOWN

724.0 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Mercedes in cooperation with Getrag had developed 7-speed DSG (7G-DCT) with a dual clutch by 2012. This transmission is intended for vehicles of А, B, CLA, GLA classes.

Mercedes has taken into account the experience of VAG in this field and equipped its DCT with a wet clutch, which can operate withmore powerful engines. This transmission is equipped with an electric oil pump, which is engaged when a quick start is required or in case of the maximum load.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DCT	FWD	350	7,2	6	236.21

Technical issues and repair guidelines

The fluid quality monitoring is the only measure required during the first years of operation of this transmission. After 60-80 thousand kilometers, it is recommended to check the fluid state and change with the filter, if some contamination or smell is detected. Mercedes engineers delicately adjusted the mechanism of gears shifting in this transmission and ATF contamination can significantly change the performance capacity of the dual-clutch mechanism.

Therefore 7-DCT has two fine mesh filters:

1. One filter is positioned In the pan – metal-plastic filter with a felt membrane. It is recommended to replace it and change fluid after 100 thousand kilometers.

2. The second filter is placed outside – the filter-cartridge. It should be replaced yearly or after travelling 30-40 thousand kilometers.

How to repair this transmission (Videos)

7G-DCT

Mercedes-Benz 7G-DCT

7G-TRONIC PLUS

7G-TRONIC Plus Transmission

Instruction manuals and useful links

Link type	Source	Description
pdf	autocats.ws	System description 724.0
web	bevo.mercedes-benz.com	7-G DCT transmission oil
pdf	alltranz.co.nz	Scheme 724.0

A727 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The A-727 is a 3- speed automatic transmission designed and manufactured by Chrysler in the early 1960-s (replaced A488). Since then, this gearbox mainly had been mounted on a different Chrysler cars. This gearbox is extremely adjustable and powerful enough to operate with 450hp engines. Therefore, A-727 may be easily used for Chrysler, GM or AMC vehicles.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		8,2	3,8	Mopar ATF+3

Technical issues and repair guidelines

This type of transmission may be specified by peculiarly shaped 14-bolt oil pan. The A-727 uses a paper fluid filter and has 2 transmission bands (reverse and kick-down). It had been one of the most adaptable Chrysler gearboxes for over 3 decades, due to its durability and efficiency. Therefore many automakers selected A-727 for their products.

After some time this transmission received new names and broken up into 2 categories of the 36RH and 37RH gearboxes, where "3" specifies that it is a 3-speed gearbox, "6/7" are strength indications, "R" means that it is designed for RWD application.

How to repair this transmission (Videos)

A727 Transmission Rebuild - Part-1

727 from a first gen Cummins rebuild part 1

727 from a first gen Cummins rebuild part 2

Instruction manuals and useful links

Link type	Source	Description
pdf	shop.ukrtrans.biz	Repair manual A727
web	hotrod.com	15 Tips to Improve Your 727 Torqueflite Trans
web	novak-adapt.com	Guide to the Chrysler 727
web	Wikipedia	TorqueFlite A727 (36RH/37RH)

MENA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

MENA is a continuously variable transmission of the first generation produced by Honda (all range including MENA, SETA, SENA, META has a common name Multimatic). These transmissions had been installed in Honda HR-V of the first generation from 1998 until 2005. In fact, it is one CVT which has 4 modifications.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		5,9	3,2	Honda Genuine CVT

In fact, these CVTs (together with M4VA (S4VA, S4PA, S4MA)) are considered to be one of the oldest CVTs produced by Honda.

As a matter of fact, it is one CVT in several modifications. Modifications of CVT are bound to letter designation of the car body:

· GH1 – MENA

· GH2 — SETA

· GH3 – SENA

· GH4 – META

Typical issues

Honda CVTs related to the Multimatic series (META/SETA/SENA/MENA) usually have the same issues as CVTs of the M4VA (S4VA,S4PA,S4MA) series. Actually, META series was designed on the basis of the M4VA

-Problems with starting from the rest (jerks, speed drift when applying D+brake). This problem is fixed by replacement of the start package valve. In neglected cases specialists replace the start package.

-Problems with speed drifts in the process of acceleration have 2 solutions: 1) Replacement of the gear ratio valve 2) replacement of seals on the input shaft. This procedure requires partial disassembly of the gearbox. It is desirable to use the original repair kit of gaskets.

-Problem with the reverse. This problem is caused by damage of reverse brake elements. This problem is solved by CVT disassembly and welding. In addition, it is required to replace piston rubbers of the reverse brake – these rubbers may tear leading to problems with the reverse.

To prevent any further problems with the reverse, it is recommended to replace reverse friction clutches.

AP2 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

AP is the 4-speed automatic gearbox created by Automotive Products and the BMC for MINI vehicles. The prototype of this famous gearbox was released in 1962. It took about a decade of engineering and manufacturing efforts before ordinary 2-speed gearbox turned into the unique 4-speed automatic gearbox.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD

Technical issues and repair guidelines

This was a great achievement to manufacture a 4-speed automatic gearbox that could be operated like a manual unit. It was one of the first automatic gearboxes with east-west mounting produced for FWD vehicles. Moreover, the construction of this gearbox implies the usage of lubricating oil instead of common ATF. This gearbox was also installed in BMC ADO16 and Austin vehicles. Specialists claim, that the crankcase oil should be changed every 10 thousand kilometers, because the oil condition is very important for this type of gearbox. One of the most common malfunctions in this transmission is related to the F-clutch that may get out of order because of the gearbox construction peculiarities (clutch gets the drive torque after multiplication via the gearbox).

How to repair this transmission (Videos)

Classic Mini Remote Gearbox Rebuild

Old Classic Mini Gearbox Rebuild - Part 1

Old Classic Mini Gearbox Rebuild - Part 2

Old Classic Mini Gearbox Rebuild - Part 3

Old Classic Mini Gearbox Rebuild - Part 4

Classic Mini Differential Rebuild - Part 1

Classic Mini Differential Rebuild - Part 2

Classic Mini Idler Gear - Setting The End Float

Fitting the crankshaft and checking the endfloat

Fitting the pistons, camshaft & oil pump

Setting the cam timing

722.2 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The first two modifications 722.1 and 722.2 of the family of automatic transmissions are rarely found in repair services. Commonly, this automatic transmission is installed on cars produced in the 80th. Owners of cars with the 722.2 transmission prefer the transmission rebuilding in order to preserve a rare car.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		7	4	236.12

Technical issues and repair guidelines

Visually the automatic transmission 722.2 is distinguished by small square pan with reinforcement ribs. The automatic mechanism controlling the process of gear shifting is located in the pan of the housing and appears to be a separate unit in contrast with automatic transmission designs of the following series. Shafts and planetary gears in this automatic transmission are highly precise and of high quality almost without application of aluminum alloy and plastic, seals are made of metal rings. The resource of these parts is much higher than the resource of friction components and in some cases of the car itself. If the transmission starts to transmit the rotation of shafts improperly, shifts gears with jolts, then it is required to perform the emergency repair (in this case replacement of some friction elements). Further usage of a faulty transmission may lead to its replacement. Signs of pumps damage consist in leaks between the transmission and the torque converter. In case of the pump wedging, it is required to replace the torque converter.

How to repair this transmission (Videos)

Mercedes 190E Teardown

Instruction manuals and useful links

Link type	Source	Description
web	Wikipedia	Mercedes-Benz first series automatic transmission
pdf	transmax.co.nz	Scheme 722.2
web	cardiagn.com	Download link on Manual 722.2
web	cardiagn.com	722.1-722.2 Transaxle Service Manual See link

BW65/66 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

BW65/BW66 automatic transmission is mounted on the BMW Bavaria (1971 – 1974) and Jaguar XJ6 (1980-1987). This complex system combines electronic, mechanical and hydraulic components. But despite of high degree of safety some problems may occur in the process of transmission operation.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		10	4-4,5	ATF Type F

Technical issues and repair guidelines

When the slippage takes place during the operation of this type of transmission it may lead to slow gear-shifting and vibrations, therefore it is an important signal for visiting repair services.

The most common problems related to this transmission are:

- shortage or surplus of oil;

- long slippage;

- sharp driving dynamics.

The sleeve and other parts of BW65/66 transmission can get overheated that usually leads to overheat cracks and other mechanical damages.

BW35 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The BW-35 is an A/T manufactured by the BorgWarner in the 1950s particularly for engines with the capacity of less than 200 cu.in. The modification 35 is a 3-speed A/T coupled to the engine by a three-element torque converter.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		8,2	4,5	Type F Fluid, Dexron II

Technical issues and repair guidelines

Engine power is converted into hydrokinetic energy and this provides smooth application or driving torque. This transmission has 3-forward and 1- reverse transmission ratio. It was constructed for operation with Type-F oil, which is not so popular today as Dexron.

The hydraulically operated control unit includes a valve location and a pump activated by the engine. The automatic gearbox includes a planetary set having 2 center gears, 3 sets of 3-epicyclic gears which can be found in a planet gear holder and follower gear.

Instruction manuals and useful links

Link type	Source	Description
pdf	volvoenthusiastsclub	Repair manual BW35

FW6AEL Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed FWD automatic transmission FW6A-EL with the east-west mounting was developed by Aisin for Mazda. This transmission was installed on Mazda CX-5 with the 2.0 liter engine, Mazda-3, Mazda-6. In terms of design, this transmission is very similar to the U660E transmission produced by AisinWarner. This transmission is considered to be the main competitor of ZF 6HP19-21. The FW6A-EL transmission has the torque converter with a double lock-up clutch that helps to accelerate the transmission faster and with higher efficiency. However, frequent usage of kick-down may lead to failures. This transmission employs reliable Aisin solenoids – linear type solenoids with anodized manifold, which is built into the solenoid body.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD	300	8	5	ATF-FZ Skyactiv

This transmission is a “rare guest” in the repair services, repair specialists mainly change oil and filter. It is recommended to change ATF after reaching the mileage of 100 thousand kilometers, and then every 50-60 thousand miles. It is required to monitor ATF transparency regularly, because with aggressive driving style ATF may get contaminated much earlier. In rare cases, transmission specialists face the problem when the torque converter lock-up damages the pump. The issue is expressed in vibrations and leakages through the pump seal. In this case specialists not only replace the seal, but also repair the torque converter and replace clutches. Another problem, similar to the issue in U660E, is wear of the case center bearing. This problem occurs when drivers get carried away with the kick-down on cold oil. One more typical problem of this transmission is damage of the double drum High/Low. After running 100 thousand kilometers it is also recommended to monitor the ATF temperature and the heat exchanger operation, similar to VW problems with the TF60-SN transmission. In old cars repair specialists advice to clean the heat-exchanger during full ATF change, to ensure reaching of 300 thousand kilometers mileage before the overhaul.

Instruction manuals and useful links

Link type	Source	Description
pdf	alltranz.co	Scheme FW6AEL
web	nema.club	DTC P0731 1GR incorrect ratio
web	nema.club	DTC P0746 Pressure control solenoid stuck off

C635 DCT Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed C635 dual dry clutch transmission (DDCT) was produced by Fiat and was presented in 2010 with AWD, FWD, and manual versions. Since then, this transmission has been installed on Alfa Romeo 159, Brera, Gulia, Milano, MiTo, Spider. This transmission was designed thanks to collaboration of Fiat, Magnetti Marelli and BW. The maximum torque transmission capacity of the C635DDCT is equal to 350 Nm.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	DCT	FWD	350	2,1	1,9	Addinol ATF DCT

The total weight of this transmission is 81 kilograms, including ATF and TCU. The advanced technologies implemented in this transmission guarantee uninterrupted torque transmission and traction without any losses of power in the process of gear shifting. The Start/Stop feature helps to reduce fuel consumption by 10% in comparison with standard hydro-mechanical transmissions.

Transmission repair specialists point out that the C635DDCT transmission is extremely sensitive to the ATF condition. Constant monitoring of the ATF status may prolong the service life of this transmission.

How to repair this transmission (Videos)

Fiat Dual Dry Clutch Transmission

Instruction manuals and useful links

Link type	Source	Description
web	Wikipedia	FPT C635 DDCT transmission

TF690 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The CVT transmission version named TF690 (Lineartronic) was designed in 2008 for Subaru Outback with the engine capacity equal to 2.5 liters. The second generation was named as TR580. In 2010, this CVT was tested on Impreza with the engine capacity from 1.6 to 2.0 liters. Starting from 2012, this transmission also found application on other Subaru models. The design of middle class CVTs includes a chain instead of a push belt. This CVT is quite sensitive to the fluid state, its cleanness and temperature. There is a special type of oil for this CVT named as SUBARU CVT Oil Lineartronic II (K0425Y0710).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	AWD	350	12,5	5,6	SUBARU CVT Oil Lineartronic II

Technical issues and repair guidelines

The repair kit of gaskets and seals is used to replace rings and gaskets. Rubber rings are replaced when the CVT unit is overheated or if it operates with contaminated fluid (including chips) for a long time. In case when frictions burn to the glue layer, the filter with the mesh is also replaced in the process of the TF690 reassembly. Burnt frictions and Forward steel discs are the first to be replaced. Next on the popularity of the replacement are the metal frictions of the Starter package. The starter pack is responsible for turning the cones on and off when stopping and shifting the lever to the neutral position. Transfer frictions also appear in replacement operations. They are responsible for distribution of torque on rear\front wheel drive.

The TR580 unit has problems with the valve body and a set of solenoids. In previous models these components caused the failure of electrics when the transmission operated with contaminated oil for a long time or under extreme loads and temperatures. When the wear-out of the belt and cones is neglected, then it is necessary to replace the cones. A typical problem with CVT cones in Subaru is related to the input shaft bearing, pressed in the transmission body. This bearing is cranked by vibrations at maximum speeds, and then it breaks.

How to repair this transmission (Videos)

Valvebody Replacement with code P2764

Breaking down a TR-580

GS7D36SG Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic transmission GS7D36SG was designed by 2008 for BMW vehicles with engines having the torque up to 400 Nm. This transmission has 7 speeds and minimum possible 100 ms of the torque disruption. This transmission also named as M-DCT and DSG-7 BMW. Initially this transmission was installed on rare BMW M3, Z4. After testing, computer adjustment, improvement of the cooling system this transmission was offered for cars of E90/92/93 series, and later for E82/88 series. In addition to impressive characteristics of the acceleration dynamics this transmission has a solid reserve in durability (for 100 thousand kilometers).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DCT	RWD	400	9,5	5	83222148578

Technical issues and repair guidelines

Manuals say that it is not necessary to change ATF for this transmission during the whole service life of this unit, but repair specialists recommend to perform this procedure to prolong the lifespan of this transmission. This transmission has all modern security systems from overheating. Friction components are selected with steel discs for each type of engines, require correct positioning during installation (for efficient cooling),violation and get burnt in case of violation of operation rules. The friction lining wear-out increases clearances in the package and the transmission starts shifting gears improperly. Before replacement of friction components it is recommended to consult an authorized DSG BMW service, because it may be possible to adjust shifting with worn-out frictions with the use of software.

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme GS7D36SG, DCI600

CTX Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In 1987 Ford and Fiat started to produce the type of automatic transmission called CVT. This innovative system was designed on the basis of the Van Doome mechanism, which was installed in small cars (DAF) in 1955.

The Ford CTX transmission operates on the principle of belt driving applied in Van Doome transmissions, but with some peculiarity, namely, usage of a single steel belt (operating in compression) instead of two rubber drive belts (operating in tension).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		3,6		MVATF PLUS

Technical issues and repair guidelines

This type of gearboxes is used for FWD vehicles with the capacity up to 1.6 liters. It is claimed, that this transmission is more economically viable solution in comparison with usual automatic gearboxes.

This transmission has a smoothly shifting gear ratio over the entire speed range. Transmission of the torque from the engine to the main drive shaft is performed not via converter, but through the multi-plate clutch. The transmission control unit provides an optimal gear ratio for any driving mode with a maximum efficiency coefficient of the engine. There is a kick-down mode which facilitates to the speed increase in cases of overtaking or uphill movement. This mode is activated when the accelerator pedal is fully depressed and held in this state.

Instruction manuals and useful links

Link type	Source	Description
pdf	alltranz.co	Scheme ford ctx
web	pirmil.info	Scheme image CTX

722.7 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission 722.7 (W5A180) had been used since 1998 until 2005 on vehicles of А-class (A168, А190) with the engine capacity up to 2.0 liters as well as on VANEO (W414) with the same type of engines.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	FWD	205	6,3	3,3	236.12

Technical issues and repair guidelines

Before covering 200 thousand kilometers these automatic gearboxes get in repair services for 2 reason

1. The clutch drum К1

Due to construction peculiarities of the 722.7 unit and its valve body (VB), at one of the phases of clogging and aging of the 722.7 electrics transmitted excessive pressure on this pack damages the metal of the drum with the piston or pulls out the closing ring, that leads to slipping and necessity for change of the entire clutch cover K1. Preventive measures include well-timed cleaning of the VB unit, or well-timed change of the TC lock-up clutch after gearbox travels 150-200 thousand kilometers.

2.Valve body electronic plate

For proper diagnostics and repair estimation, it is necessary to obtain error codes. Change of the board sensors or wiring of solenoids demands classification of the specialist and programming capabilities for encoding the plate for VIN of the car. Mercedes electronic boards are sensitive to the water, temperature difference, metal chips in oil. Each time diagnostics detects various causes of abnormal operation. The minor repair helps to delay the preventive repair for several years by means of cleaning\washing of the VB unit, repair of the electric plate with broken sensors. Operation with overheated oil damages the electronic plate extremely fast.

How to repair this transmission (Videos)

inspect Mercedes A class automatic gearbox

slipping in first gear

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Electronic and Solenoids scheme

K210 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

TOYOTA K210 / XA-15LN

Simultaneously with the first generation of CVTs (K110/K111/K112), the Japanese company Aisin designed a lightweight CVT version K210 intended for small cars (with engine capacity of 1.0-1.5 liters). The right-hand drive Toyota Vitz (engine capacity 1.3 liters) was the first car equipped with this CVT. This car was intended for sale on the domestic market of Japan. Toyota wanted to test this CVT in Japan and fix all possible issues. The first upgrade of K210 was implemented in 3 month after its launch – Aisin engineers changed the belt. This measure helped to improve the car performance reliability at idle speed. In 2004, CVTEC Co., Ltd started production of 30-millimeter CVT belts, which found application in K210 (before that, the K210 gearbox was equipped with the belt of the Dutch company VDT BV).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	145	8	5	Aisin CVTF7004, Toyota 08886-02105

For the external market (car models not including Toyota), Aisin produced the modification of K210 named as XA-15LN. From 2007 to 2014, this CVT had been successfully used by the company Mazda in its cars (Mazda Demio and Mazda Axela). It should be noted that modifications of the K210 transmission are not interchangeable (or partly interchangeable).

The range of K210/XA-15LN did not receive any continuation. CVTs of this series were installed on a limited number of models of Toyota and Mazda for the domestic market of Japan. These CVTs had been produced before the end of 2015.

In 2004, Aisin developed a new range of CVTs (K410/K411) for Toyota cars with 1.3-1.5 liter engines. This series turned out to be quite successful.

Typical problems:

1) CVTs of K210/XA-15LN series (as well as other CVTs produced by Aisin) are extremely sensitive to ATF quality. In this case, we are talking not only about the presence of metal shavings in ATF, but also about ATF overheating. Shavings in ATF are actually abrasive particles, which eventually (if ATF is not changed) damage Teflon rings in CVT. Then it leads to ATF pressure drops in the transmission itself. Severe wear of Teflon rings over time leads to damage of friction clutches and steel discs.

2) Overheating of the CVT K210/XA-15LN often leads to complete replacement of friction discs. If the driver continues using the transmission with burnt ATF for a long time, then ATF not only loses it qualities and cools the transmission insufficiently (often it leads to overheating and replacement of pistons), but also poorly lubricates cones (especially in winter mode). It leads to slipping of the belt in winter time. Early versions of K210-11A CVT modifications were equipped with belts of the company VDT BV. These belts are not interchangeable with later modifications of belts produced by “CVTEC Co., Ltd.”.

3) Shavings (if ATF is not changed) reach bearings on the input and/or output shaft of cones and eventually one of bearings starts “buzzing”. Bearings are not very expensive, but replacement of

the “buzzing” bearing is possible only with removal and complete disassembly of CVT (this procedure is time-consuming).

4) Some drivers had to deal with the problem of seal leakages in K210. Replacement of seals is usually combined with ATF change

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Daihatsu	BOON	10-16	CVT FWD	L4 1.3L
Daihatsu	BOON/BOON LUMINAS	10-11	CVT F/4WD	L4 1.3L
Subaru	TREZIA	10-16	CVT FWD	L4 1.3L
Suzuki	SPLASH	08-11	CVT FWD	L4 1.2L
Suzuki	SWIFT	07-11	CVT FWD	L4 1.2L
Toyota	PASSO	10-16	CVT FWD	L4 1.3L
Toyota	RACTIS	06-11	CVT FWD	L4 1.3L
Toyota	VITZ	05-16	CVT FWD	L3 1.0L

VT2 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The CVT VT2 transmission was released in 2009 and was offered to numerous carmakers (Brilliance/BYD/Chery/Geely Emgrand/Great Wall/Tengyi/Haima 3/Freema/Hyundai Avante HD hybrid/Huandong /Toyota Vitz).

CVT transmissions VT1 and VT2 have a reliable design (with a significant safety margin of transmission components) with a push belt. For many years, maintenance and repair services for this CVT are limited to change of oil and filter, and later – replacement of the Bosch belt.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	182	8	3,1	EZL-799-A45

The software of VT1,2 is designed to spare expensive cones at low speeds, when the belt and surfaces of cones operate very intensively. The cones have wear-resistant coating of operating surfaces implemented with the help of space technologies. These cones cannot be rebuilt and are not supplied to repair markets. The valve body filter in the VT2 transmission is based on Jatco solutions.

Rare overhauls accompanied by reassembly of spare parts, the wear of which leads to pressure losses on the friction clutches and their consequent wear, require the repair kit of gaskets and seals. Repair specialists prefer to use Precision repair kit.

Experienced transmission repair specialists, who work with VT1 and VT2 transmissions, change the filter and ATF as often as possible, because it is extremely hard to find spare parts for these transmissions. While changing the filter and ATF specialists usually check the chain (belt) for wear of the protector and in case of any suspicion of wear – replace the belt. The 30-40% wear of the belt teeth increases the risk slippage (metal-on-metal), even with the common (not sports) acceleration to outrun the truck ahead.

If the surfaces of cones have tears or "pits", then specialists advice to replace the CVT instead of its repair. Generally, the VT2 transmission is considered to be "invincible” under the condition of proper maintenance. Today, it is one of the best CVTs on the market.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Beijingauto	C51	15-16	CVT FWD	L4 1.5L
Beijingauto	D50	14-16	CVT FWD	L4 1.5L
BYD	F3	09-16	CVT FWD	L3 1.0L
BYD	G3	09-16	CVT FWD	L4 1.8L
BYD	L3	10-16	CVT FWD	L4 1.8L
Dongfeng	JOYEAR S50	15-16	CVT FWD	L4 1.6L
Emgrand	EC8	13	CVT FWD	L3 1.0L
Geely	EMGRAND EC7	09-16	CVT FWD	L4 1.3L 1.8L
Geely	EMGRAND EC7-RV	10-16	CVT FWD	L4 1.8L
Geely	GLEAGLE GC7	16	CVT FWD	L4 1.5L
GreatWall	M2	10-16	CVT FWD	L4 1.5L
GreatWall	VOLEEX C30	10-16	CVT FWD	L4 1.5L
Haima	FAMILY	07-16	CVT FWD	L4 1.6L
Haima	M3	13-16	CVT FWD	L4 1.5L
Haima	M5	14-16	CVT FWD	L4 1.5L 1.6L
Haima	M6	15-16	CVT FWD	L4 1.5L
Haima	PREMACY	09-16	CVT FWD	L4 1.6L 1.8L
Haima	S5	14-16	CVT FWD	L4 1.5L 1.6L
Jianghuai	HEYUE	14-16	CVT FWD	L3 1.0L
Jianghuai	HEYUE A30	14-16	CVT FWD	L4 1.5L
Jianghuai	HEYUE RS	14-16	CVT FWD	L3 1.0L
Jianghuai	REFINE S5	16	CVT FWD	L4 1.5L
Jianghuai	S3	14-16	CVT FWD	L4 1.5L
Proton	EXORA	09-16	CVT FWD	L4 1.6L
Proton	IRIZ	14-16	CVT FWD	L4 1.3L 1.6L
Proton	PREVE	12-16	CVT FWD	L4 1.6L
Proton	SAGA	11-16	CVT FWD	L4 1.3L 1.6L
Proton	SUPRIMA S	13-16	CVT FWD	L4 1.6L
Soueast	BOLANG	15-16	CVT FWD	L4 1.5L 2.0L
Soueast	V3	10-16	CVT FWD	L4 1.5L
Soueast	V5	12-16	CVT FWD	L4 1.5L
Soueast	V6	13-16	CVT FWD	L4 1.5L

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme VT2

0AW Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

8-speed CVT 0AW (VL380) was produced by Audi in 2004 for 4WD Audi models (from А3 (Sportback) to А7 (Sportback)) with gasoline engines from 1.8 to 3 liters to replace the 6-speed transmission 01J.

In 2007, the new modification of this transmission named VL381 was produced. This CVT inherited only few spare parts (friction elements, steel disc etc) and the operation principle from its predecessor 01J. Electric components and the valve body were significantly improved. This smart transmission can send a huge torque (for CVTs) - up to 400Nm.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
8	CVT	FWD/AWD	400		5.5-7	G 052 516 A2

Technical issues and repair guidelines

There is still some old peculiarity of this transmission, which is related to the pulling chain – if the car equipped with this transmission is used for towing, then the cones with the chain get damaged without a chance for repair.

Parts for repair of the 0AW transmission (besides an internal filter) are quite rare and available on request. For example, one of the typical issues is burning of the clutch drum. The internal filter is the same as for VL380 and 381. Filters are produced for deep and small pans.The list of required spare parts also includes the belt, which should be replaced without waiting for the moment when very expensive cones may be damaged. The price of these cones is comparable with depreciation value of the vehicle itself.

The pulling belt gets stretched pretty fast because of extreme loads. Automakers give different figures regarding the belt service life before it should be replaced, but all of these figures are much lower than 200 thousand kilometers, therefore the belt is included in every second order for the overhaul of the 0AW transmission. In rare cases, it is necessary to replace a very expensive TCM (control unit) – valve channels of this control unit can be damaged by contaminated ATF.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A4	07-16	CVT FWD	L4 1.8L 2.0L V6 2.7L 3.0L 3.2L
Audi	A5	06-16	CVT FWD	L4 1.8L 2.0L V6 2.7L 3.0L 3.2L
Audi	A5 SPORTBACK	09-16	CVT FWD	L4 1.8L 2.0L V6 2.7L 3.0L
Audi	A6	11-16	CVT FWD	L4 2.0L V6 2.5L 2.8L 3.0L
Audi	A7	10-16	CVT FWD	V6 2.5L 2.8L 3.0L

How to repair this transmission (Videos)

DL501 Wet Dual Clutch

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme 0AW
web	workshop-manuals.com	Draining ATF and filling up after repairs
web	workshop-manuals.com	Removing and installing gearbox

TR80SD Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 8-speed 0С8 (or TR-80SD according to Aisin) is a new generation of Aisin RWD transmissions. It was designed in 2006 for VAG (Volkswagen-Audi) as an alternative to DSG, which still can not function reliably with powerful engines.

This transmission was installed on Audi Q7 equipped with diesel engines V6-V8 from 3 liter capacity, and the torque capacity over 700 Nm. The same trasnmission design adapted for off-road Lexus cars has been used since 2007 under the name AA80E\F.

In the winter of 2010, this 8-speed transmission fully entered the foreign market, where it replaced its 6-speed predecessor TR-60SN on Porsche Cayenne (2010 - 2014) and on Tuareс (2010 - 2014) in different sub-versions for TDI diesel engines with the capacity from 3.0 up to 3.6 liters (Audi -TFSI). This transmission was used by American automakers for Cadillac CTS VSport in 2014 under the name TL-80SD. The competitive model for above mentioned gearbox is ZF 8HP70. This transmission was designed with usage of successful TR60-SN elements, but the valve body and the overall construction of transmission components and electrics were significantly modified. Most of the parts are not interchangeable with the predecessor. It is the most powerful of modern RWD Aisin transmission capable of transmitting the torque up to 800 Nm.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
8	AT	RWD/AWD	850	10,5	8	Toyota ATF WS

Technical issues and repair guidelines

This gearbox as all Aisin RWD transmissions is considered to be “invincible” and maintainable, designed to travel up to one million kilometers with minimum number of overhauls.

The repair kit of gaskets and seals is ordered for reassembly in order to restore leak resistance of jointing edges by replacement of rings and gaskets that helps to the valve body in regulation of gear shifting by the oil pressure. The whole kit of friction elements is replaced when some components get burned. At the same time, it is recommended to change the torque converter frictions in case of burned ATF.

For this transmission automakers used a new torque convertor with a multi-disc lockup clutch in order to guarantee a prolonged service life of torque converter frictions (over 200 thousand kilometers) and at the same time allow the driver to accelerate with the help of forced blocking of the torque converter lock-up clutch in "slippery mode". It significantly increases the transmission efficiency, improves acceleration characteristics, but wears out hard-working frictions of the lock-up. The valve body of this transmission differs from its predecessors TR-60 and TF-60. This valve body will get clogged if it is used with contaminated ATF for several years. Aisin solenoids in contrast to ZF solenoids can withstand much more open-close cycles.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	Q7	09-15	8 SP 4WD	V6 3.0L V8 4.2L
Porsche	CAYENNE	10-16	8 SP 4WD	V6 3.0L 3.6L V8 4.2L 4.8L
Porsche	PANAMERA	11-16	8 SP RWD	V6 3.0L
Volkswagen	TOUAREG	10-16	8 SP 4WD	V6 3.0L 3.6L V8 4.2L

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme TR80SD

JF009E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The constantly variable transmission (CVT) JF009E (RE0F08A) is constructed for the class "mini" and can be paired with engines up to 1800 cm3. In 2002, the RE0F08A unit replaced not very popular RE0F21A modification.

The JF009E transmission found application in various Nissan models, (1.8L Nissan Serena, March, Cube 2000-09, Micra 03-09. FIAT Punto, Palo, Uno 03-09...), but became more popular in Nissan Cube, Tiida and Wingroad. In terms of design, this CVT is similar to neighboring Jatco variators and comes between highly-demanded JF011E (for the middle class) and JF015E (for the class mini/micro). Many spare parts from the RE0F21A unit are interchangeable.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	175	8,3		CVT Fluid NS-2

Technical issues and repair guidelines

The main repair procedure for this invincible gearbox lies in fluid change and filter replacement. This CVT is sensitive to contaminated and cold transmission fluid. But in general, components of this CVT have an immense reserve for aggregated engines, serving for a long period of time even with contaminated fluid and clogged filters. The main coarse filter (made of metal with a mesh) is located in the pan and operates for a long period of time. This CVT also has an external fine filter, which is usually changed every 50-60 thousand kilometers. The reassembly includes spare parts replacement (Repair kit of gaskets and seals).

The design of this CVT family is developed for engines with a higher torque and has such a solid reserve of CVT components, that it gets in repair services when the car itself exhausts its resource, therefore repair procedures in these CVTs are so rare.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Nissan/Datsun	CUBE	08-16	CVT F/4WD	L4 1.5L
Nissan/Datsun	CUBE/CUBE CUBIC	02-12	CVT FWD	L4 1.4L 1.5L 1.8L
Nissan/Datsun	MARCH	06-12	CVT FWD	L3 0.9L
Nissan/Datsun	NOTE	05-12	CVT FWD	L4 1.5L
Nissan/Datsun	TIIDA/TIIDA LATIO	05-12	CVT FWD	L4 1.5L 1.8L
Nissan/Datsun	VERSA	06-13	CVT FWD	L4 1.8L
Nissan/Datsun	WINGROAD	05-16	CVT FWD	L4 1.5L 1.8L

How to repair this transmission (Videos)

RE0F08A JF009E valve body

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.es	Scheme JF009E
pdf	textfiles.com	Service manual RE0F08A

TW40E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission A174 (TW-40) belonging to the "micro" class with a rear drive was designed by Aisin in 1998 on the basis of 3-speed predecessor А172. After testing and update, this transmission was installed on Suzuki Jimni, Escudo, Avery (Landy) with engines from 0.7 up to 1.3 liters. This automatic transmission is considered to be a modern, economical and “invincible” unit for the minimum torque (up to 120 Nm). Americans had been using TW-40E on Ford Pronto with 3-cylinder liter engine until 2007.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/AWD	120	3,7	2	Dexron III

Technical issues and repair guidelines

For reassembly of the A174 unit repair specialists order the repair kit of gaskets and seals, clean the valve body and replace spare parts, and rebuild the torque converter. Transmission experts assume that it is necessary to replace all friction clutches (soaked with oil combustion products) in transmissions operating with burnt oil.

The valve body design of this transmission includes "On-Off" solenoids (responsible for gear shifting and the torque converter lock-up operation), and a big EPC solenoid. Solenoids are adjusted quite accurately and ensure the torque converter actuation without a hard slippage. Therefore the torque converter does not overheat or smudge solenoids too much, allowing solenoids to operate for quite a long time. Sometimes problems occur in wiring of solenoids.

In the process of complete reassembly of А174/TW-40E, transmission specialists replace the following repair kits with the aim to prolong the operation period of the unit:

- Kit of steel discs TW-40E

- Kit of traversing pistons (6 pieces)

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chinamotor	VERYCA BUS	01-03	4 SP RWD	L4 1.2L
Mitsubishi	MINICAB VAN	99-16	4 SP R/4WD	L3 0.7L
Mitsubishi	PAJERO MINI	00-12	4 SP R/4WD	L4 0.7L
Proton	JUARA	00-04	4 SP RWD	L4 1.1L

6DCT150 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed 6DCT150 was developed by the company Dongfeng Getrag. It is considered to be the most space-saving dual-clutch gearbox worldwide. "Cascading Gears", implemented in this transmission, helped to reduce the total weight of the gearbox. Another feature called "Smart-Actuation” contributed to significant reduction of energy consumption. This transmission operates with engines, which have low torque. It is intended for compact and medium cars.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	DCT	FWD		1,8	1,8	75w90

Technical characteristics of 6DCT150: wet clutch, 6 forward gears, 1 rear gear, maximum torque reaches up to 130-190 Nm (the most popular torque range for passenger cars). This transmission has undeniable technical advantages in its class. The 6DCT150 is notable for its efficiency, resistance to loads, great "efficiency / cost" ratio. When compared to traditional automatic transmissions, 6DCT150 ensures faster gear shifting.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dongfeng	A60	15-16	6 SP FWD	L4 1.4L
Dongfeng	AX3	15-16	6 SP FWD	L4 1.4L
Dongfeng	H30	16	6 SP FWD	L4 1.5L
Dongfeng	JOYEAR	16	6 SP FWD	L4 1.5L 1.6L
Dongfeng	JOYEAR S50	15-16	6 SP FWD	L4 1.4L 2.0L
Dongfeng	JOYEAR X5	16	6 SP FWD	L4 2.0L

How to repair this transmission (Videos)

Getrag 6DCT150

Instruction manuals and useful links

Link type	Source	Description
pdf	getrag.com	Technical data 6DCT150
pdf	getrag.com	Press information

P110 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

TOYOTA ECVT P110 / P111 / P112 / P210 / P310 / P311 / P312 / P314 / P410 / P510

CVT-type automatic transmissions are produced by Aisin for hybrid cars Toyota and Lexus. These transmissions have an initial prefix “P” (it means that these transmissions belong to the planetary type). Some people mistakenly believe that the planetary gearbox cannot be a CVT, but it’s wrong. Planetary gearboxes (not all) have a metal chain (analog of a belt in CVT). Even Toyota considers these planetary gearboxes as CVTs and name them as eCVTs. Undoubtedly, the planetary gearbox differs from standard CVTs (on the global scale the planetary gearbox is not so complicated as CVT), but it is still CVT with its problems and repair peculiarities.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	ECVT	FWD				TOYOTA CVT FLUID FE

The first CVT of the planetary type eCVT (model P110) was manufactured in 1997 and was installed on the first generation of Toyota Prius for the domestic Japanese market. In 2000, this CVT was upgraded for Prius and was named as P111. Toyota Prius equipped with the P111 transmission was sold not only in Japan, but also in the US.

The new planetary CVT P112 was designed in 2001. This gearbox was intended for more powerful (2,4 liter engines) and heavyweight cars (Toyota Estima Hybrid and Toyota Alphard Hybrid). The planetary CVT transmission P112 found application in Toyota Prius, which was sold in Europe, Canada, and USA. The P112 actually became one of the most popular CVTs of planetary type.

The planetary CVT P310/Q211 (named as Q211 for Lexus) was manufactured in 2005. This transmission was specially developed for SUVs with FWD and 3.3-3.5 liter engines. This transmission was installed on hybrid cars Lexus RX400H, Toyota Kluger Hybrid.

The planetary CVT P311 was released in February 2006. It was intended for FWD cars with 2.4 liter engines. In comparison with P112, this gearbox is noted for reduced fuel consumption when the engine

has high RPM rates. In the same year, Aisin started production of the transmission P312 which was designed on the basis of P311. This transmission was supplied to Nissan Motor Company Co., Ltd (for application in Nissan Altima Hybrid in the US market. It was also installed on Toyota Harrier Hybrid 3,3 for the domestic market of Japan.

The eCVT P410 was launched in production in 2009. This transmission was developed for FWD cars equipped with 1.8 liter engines. Peculiarities of this transmission include transfer gear case assembly and possibility of smooth reduction of the engine speed at high RPM rates. This eCVT as well as P112 found application at a global scale, because it was installed on Toyota Prius, which had been sold from 2009 to 2015 all over the world. In addition, the P410 transmission was used for a new range of cars ( Toyota Prius Alpha, Toyota Prius V, and Lexus CT200H.

In July 2009, Aisin released a new modification of eCVT named as P311-03A. This transmission had an upgraded oil pump and engine cooling system. In 2010, Aisin started production of the P410 planetary CVT for plug-in hybrid vehicles.

In August 2011, Aisin started production of a new planetary CVT named P314 for 2,5 liter engines (for FWD and AWD). This transmission was equipped with a new oil pump, which ensured lower fuel consumption. According to Toyota plans, this transmission also should find a global scale application, because cars equipped with this transmission are sold all over the world (Toyota Camry Hybrid (for markets of the US and Japan), Lexus NX300H (for European market), and Toyota Rav4 Hybrid (for all global markets). The P314 eCVT is considered to be quite “new” and it is rarely found in repair services.

In November 2011, Aisin released a new eCVT transmission named as P510. This gearbox has a new design and operates with an NZ-series engines (engine capacity = 1.5 liters). The list of cars which use this transmission includes Toyota Corolla Hybrid, Toyota Yaris Hybrid, Toyota Prius C. The P510 transmission in noted for its light weight, small dimensions, and increased efficiency.

In January 2016, Aisin released a new eCVT P610. This gearbox was intended for application in a new generation of Toyota Prius.

Problems and repair procedures

Abrasive particles often damage oil pump of eCVT , in case of ill-timed ATF change.

1) The planetary gear set wear is often caused by abundance of metal shavings. It is especially common for planetary type CVTs P112 installed on Toyota Prius (produced in the 2003-2008 timeframe).

2) Repair services for eCVTs often include replacement of gaskets and seals (Overhaul kits), pump seal, axle shaft oil seal.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Toyota	PRIUS	0	EVT FWD	L4 1.5L

K110 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

TOYOTA K110 / K111 / K111F / K112 / K112F / K114

The first generation of CVT transmissions designed by the Japanese company Aisin was produced in August of 2000. Initially, the CVT K110 was designed for FWD cars with the engine capacity of 2 liters. According to many sources, Toyota (co-founder and co-owner of Aisin) combined the license (bought from Jatco) and its own developments in the field of CVTs (the first CVT named as P110 was successfully tested by Toyota on Toyota Prius with the body NHW10 for the domestic Japanese market).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		8	5	Aisin CVTF7004, Toyota 08886-02105

Technical issues and repair guidelines

The first car with the K110 CVT was Toyota Opa, 2.0 (2000-2005), which was sold exclusively in the domestic market of Japan. A year later (in 2011) the K110 transmission was installed on sedans Toyota Alion/Toyota Premio and minivans Toyota Voxy/Toyota Noah/Toyota Estima, etc. All these right-hand drive cars were originally intended for sale at the domestic market of Japan as well as in some Asian countries. For 4 years of production, Toyota managed to fix some standard issues related to this CVT. In 2004, Toyota released an improved version of K110 which was named as K111/K111F (prefix “F” means that this CVT is intended for all-wheel drive vehicles).

The K111 transmission was designed on the basis of K110, and these two transmissions are very similar in terms of technical solutions. The K111 transmission (in contrast with K110) has a new belt as well as linear control over the N gear and acceleration. It has a positive impact on fuel efficiency and transmission performance characteristics.

For some time, Toyota was actually “catching up” with other Japanese companies in terms of CVT application. Therefore, Aisin (which produced CVTs for Toyota) had to use spare parts of different manufacturers for assembly of K110 and K111. Moreover, Aisin heavily depended on third-party suppliers and on quality of supplied spare parts. For example, belts for Aisin CVTs were produced by the German company Bosch. Toyota didn’t want to put up with such state of affairs. The Japanese auto giant wanted (via its subsidiary Aisin) not only to fully control the whole process of transmission production, but also to develop and introduce new CVT technologies. Thus, in 2002, Aisin jointly with Bosch established a joint company Shivutech Co., Ltd. (trade mark CVTEC). The purpose of this company was the development and production of components for CVTs. Three years later in 2005, CVTEC developed the belt for a new type of CVT.

According to the original technology, this new push belt consists of thin steel sheets with high-precision gaps (equal to several microns). This solution ensures high strength of belt elements. In addition, the durability of this belt was enhanced by the sandblasting procedure. These measures made it possible to launch in production a new series of CVTs K112/K112F in October of 2005. These CVTs with higher torque transmission capacity were initially intended for coupling with 2,4-liter engines. The first car equipped with the K112/K112F transmission was Toyota Rav4. Later this CVT was applied in Toyota Estima, Toyota Blade, Toyota Vellfire and many other cars.

Typical problems in K110/K111/K112

Transmission specialists often have to deal damage of bearings on the input shaft of K111 and K112. This problem may be caused by production defects or contaminated ATF with metal shavings. These metal shavings reach the bearing via a small hole in the gearwheel. As a result, balls in the bearing become cemented leading to its wear. Over time, the “dying” bearing damages the gear-wheel itself

If K110 / K111 / K112 transmissions get overheated (ATF has a “burning” smell), then it may lead to replacement of the complete set of friction clutches. In this case, transmission specialists also replace gaskets, rings, and seals (the reason is simple – rubber hardens affected by temperature and becomes less flexible; eventually, it leads to oil leakages. Long-term usage of the car with worn friction clutches and rings leads to overheating of pistons and their consequent replacement.

Acceleration from rest with the cold CVT (in winter time) leads to curving of the CVT belt on cones (on minimum radius). At the same time, the belt touches cones on the minimum area. It often leads to the belt slippage (with cold ATF). In this case, the belt wears down and scratches cones. With time surfaces of cones will have tears. The belt slippage also will have a negative impact on solenoid-operated valves.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Toyota	ALLION	01-16	CVT FWD	L4 2.0L
Toyota	ALPHARD	03-12	CVT F/4WD	L4 2.4L
Toyota	COROLLA	14-16	CVT FWD	L4 2.0L
Toyota	NAV1	12-16	CVT FWD	L4 2.0L
Toyota	OPA	00-05	CVT FWD	L4 2.0L
Toyota	PREMIO	01-16	CVT FWD	L4 2.0L
Toyota	WISH	03-16	CVT FWD	L4 2.0L

JF414E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission JF414 of the class “mini” with an east-west mounting for FWD cars was designed by the Japanese company Jatco for vehicles with the engine capacity of up to 1.6 liters. AvtoVaz used JF414 for Lada "Granta".

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		7	3	Matic-S

Technical issues and repair guidelines

Besides Lada Granta, this CVT transmission was also installed on Nissan Almera and March models with up to 1.6 liters. Moreover, this solution may be used on Ad Van. This CVT was developed as a budgetary and reliable option for "long-running" cars. The main competitor of this CVT is AW60-40 by Aisin.The design of JF414E components is maximally simplified according to the principle "nothing in excess"

Repair procedures and typical problems

Rebuilding procedures of this transmission are related to the replacement of spare parts (namely, gaskets, seals and friction elements).Usually repair specialists have to replace worn-out friction elements. Bearings also may be replaced in the course of the overhaul. The most common bearing to be replaced is a double-row center bearing. This bearing is damaged by overloads and driving with vibrations at high speeds.The valve body of the JF414 unit is quite reliable and rarely gets replaced.

The main spare parts of the valve body are gaskets and solenoids. The transmission exploitation with contaminated fluid, worn-out torque converter clutch, and especially overheating may shorten the service life of solenoids and valve body gaskets by several times. The list of vulnerabilities of Jatco valve bodies includes sensors and a circuit board located in the valve body. Also these valve bodies are very sensitive to contaminated and hot fluid with metal chips.Computer settings are well-adjusted for packages and the torque converter lockup, which turns on at the very end of the 3-rd and 4-th gear, allowing the friction to have quite a long service life.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LADA	GRANTA	12-16	4 SP FWD	L4 1.6L
LADA	KALINA	13-16	4 SP FWD	L4 1.6L
LADA	PRIORA	12-16	4 SP FWD	L4 1.6L
Nissan/Datsun	MARCH	10-16	4 SP FWD	L3 0.9L 1.2L L4 1.5L
Nissan/Datsun	MI-DO	15-16	4 SP FWD	L4 1.6L
Nissan/Datsun	ON-DO	14-16	4 SP FWD	L4 1.6L
Suzuki	SWIFT	11-16	4 SP FWD	L4 1.4L

Instruction manuals and useful links

Link type	Source	Description
web	transakpp.ru	Scheme

725.0 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 9-speed automatic transmission 9G-Tronic (725.0) was developed by the company Mercedes-Benz and was released in 2013, replacing the model 7G-Tronic.

When developing this gearbox, Mercedes-Benz’s transmission specialists concentrated on simplifying the structure of the transmission, while maintaining its size and implementing the solution with 9 gears, minimum number of planetary gear sets and mechanisms of gear shifting. As a result of intensive computer system analysis and synthesis, transmission engineers solved this problem by means of only 4 planetary gear sets and 6 gear shifting mechanisms.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
9	AT	RWD/AWD	1000	10,2	6	236.16

Since 2014, the 9G-Tronic transmission has been installed on cars of E-(including coupe/cabriolet) and CLS Classes, since 2015 – on GLC, GLE (including coupe), and GLS Classes. The 9G-Tronic is considered to be the world’s first 9-speed automatic gearbox in the segment of premium cars. The performance efficiency of this amounts to incredible 92% (this parameter of 7G-Tronic was equal to 85%). The span of gear ratios is equal to 9.15.

Despite two additional gears and the maximum torque up to 1000 Nm, 9G-Tronic requires the same amount of space for positioning as its predecessor. Three speed sensors monitor the operation of the gearbox and provide the TCU with relevant information for efficient gear shifting. Three different modes of operation allow the driver to pre-select an appropriate algorithm of gear shifting. It improves driving comfort and reduces the noise level.

The 9G-Tronic transmission has 3 driving modes:

«Comfort» («C») — for driving with low fuel consumption;

«Sport» («S») — for fast driving style at high engine RPM;

«Manual» («M») — for fast driving and manual gear shifting via the system DIRECT SELECT.

According to representatives of Mercedes-Benz, this transmission is suitable for cars with rear and all-wheel drive, as well as for hybrids and E-motors.

MERCEDES BENZ C CLASS L4 1.6L 2.0L 2.2L
MERCEDES BENZ CLS L4 2.2L V6 3.5L
MERCEDES BENZ E-CLASS L4 2.0L 2.2L V6 3.0L 3.5L
MERCEDES BENZ E-CLASS COUPE L4 2.2L
MERCEDES BENZ GLC L4 1.6L 2.0L 2.2L V6 3.0L 3.5L
MERCEDES BENZ GLC COUPE L4 2.0L 2.2L V6 3.0L
MERCEDES BENZ GLE COUPE V6 3.0L
MERCEDES BENZ S CLASS V6 3.0L 3.5L

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercedes-Benz	E-CLASS	16	9 SP RWD	L4 2.0L
Mercedes-Benz	GLC COUPE	16	9 SP 4WD	L4 2.2L

How to repair this transmission (Videos)

9G-Tronic transmission. Maintenance

725 0 Diagnosis of shift quality

9G-TRONIC (Gesamtsystem)

Instruction manuals and useful links

Link type	Source	Description
pdf	epfl.ch	System description 725.0
web	Wikipedia	Mercedes-Benz 9G-Tronic transmission
web	car-engineer.com	9G-TRONIC automatic transmission

724.2 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In the fall of 2010, engineers of Mercedes-Benz presented an updated version of the automatic gearbox 7G-Tronic Plus. For the first time this gearbox was applied in the CL-class (216 series). According to representatives of the company, this gearbox became more comfortable, quick-operating and economical than its predecessor. The 724.2 gearbox is equipped with the torque converter of a new generation. This torque converter is more durable; it has reduced noise level and faster response time thanks to innovative technology. In addition, this gearbox is equipped with the “start-stop” system. The engine RPM gets reduced in the ECO mode that significantly contributes to fuel economy.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	Hybrid System	RWD		9,5		236.15

The 724.2 gearbox undergone systematic optimizations to reduce energy losses caused by traction. This and other measures made it possible achieve 7% fuel economy. In 2012 a new car Mercedes-Benz SL was equipped with the 7G-Tronic Plus. The roadster became the first car of Mercedes-Benz, which was equipped with a newly developed Direct Select paddle shifter on the centre console. This feature is used for more dynamic driving style. The latest changes in 7G-Tronic Plus were introduced in 2013. The updated version of this gearbox was used in E300 BlueTEC HYBRID, where the 20 kW e-motor was integrated in the case of the torque converter. In 2013 the 7G-Tronic was replaced by the 9G-Tronic automatic gearbox.

Peculiarities:

- 7-forward gears: increased difference between gear ratios of lowest and highest gears, while maintaining small intervals between gear ratios in other gears, increases driving comfort.

- Optimal engine RPM contributed to low fuel consumption and smooth gear shifting.

- Solid power reserve: fast accelerations became possible thanks to reverse gear shifting with omitting of several gears;

- New generation torque converter: reduced wear, lower noise level and better responsiveness thanks to innovative technology.

- Reduced fuel consumption: the function “Start-Stop ECO” ensures that the engine switches off temporarily when the car gets stick in traffic jams of stops at traffic lights.

- Comfort and sportiness: drivers can choose from 3 operation modes: «E» (Economy) – to reduce fuel consumption, «S» (Sport) – for sporty driving style, «М» (Manual) – for rapid gear shifting with the help of paddle shifters.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercedes-Benz	C-CLASS	14-16	7 SP R/4WD	L4 2.0L 2.2L
Mercedes-Benz	C-CLASS COUPE	15-16	7 SP RWD	L4 2.0L 2.2L
Mercedes-Benz	E-CLASS	12-16	7 SP RWD	L4 2.2L V6 3.5L
Mercedes-Benz	GLC	15-16	7 SP 4WD	L4 2.0L 2.2L
Mercedes-Benz	ML-CLASS	15-16	7 SP 4WD	V6 3.0L
Mercedes-Benz	S-CLASS	09-16	7 SP RWD	L4 2.2L V6 3.0L 3.5L
Mercedes-Benz	S-CLASS COUPE	15-16	7 SP RWD	V6 3.0L
Mercedes-Benz	SPRINTER	13-16	7 SP RWD	L4 2.2L

How to repair this transmission (Videos)

7G-TRONIC Plus Transmission

Instruction manuals and useful links

Link type	Source	Description
pdf	europeantransmissions.com	7G-TRONIC PLUS

DQ500 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

DQ500 7-speed version DSG with a wet clutch for front-wheel drive was produced in 2009. This is a new generation of “wet” DSG for VW (Golf, Tiguan, Transporter) and Audi (A3, Q3) with TDI engines (with capacity equal to 2.0 and 2.5 l.).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DSG	FWD/AWD	600	7,6	6	G052182

Technical issues and repair guidelines

DQ500 (0BH\0BT) gearbox is sensitive to overheating and has a solid heat exchanger which may be clogged after 3-5 years of intensive operation. Therefore it requires washing during reassembly or replacement of the heat exchanger. The competitive gearbox is 09K by Aisin.This gearbox has some critical issues with Mechatronics which get clogged with dirt from the clutch cover.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A3	11-16	7 SP 4WD	L5 2.5L
Audi	Q3	11-16	7 SP F/4WD	L4 2.0L L5 2.5L
Audi	TT	09-16	7 SP 4WD	L5 2.5L
Skoda	SUPERB	15-16	7 SP 4WD	L4 2.0L
Volkswagen	CROSSBLUE	16	7 SP F/4WD	L4 2.0L V6 2.5L
Volkswagen	GOLF	14-16	7 SP F/4WD	L4 2.0L
Volkswagen	PASSAT	14-16	7 SP 4WD	L4 2.0L
Volkswagen	SCIROCCO	10-11	7 SP FWD	L4 2.0L
Volkswagen	SHARAN	11	7 SP FWD	L4 2.0L
Volkswagen	TIGUAN	10-16	7 SP F/4WD	L4 1.8L 2.0L
Volkswagen	TRANSPORTER	09-16	7 SP F/4WD	L4 2.0L

How to repair this transmission (Videos)

How to change oil

DQ250 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed DSG gearbox DQ250 - 02E (S-tronic) with a dual wet clutch was firstly used in 2003 in cars with engine capacity from 1.6 up to 3.2 l. VW started to install this gearbox serially on a number of vehicles (GOLF, JETTA, PASSAT etc). Expensive models of Seat and Scoda also were equipped with this gearbox. This gearbox is capable of transmitting quite high torque (up to 350 Nm). The structural design of this robotic transmission was created by VAG specialists jointly with the company "BorgWarner". Later this project was joined by the company "Luk".

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	DSG	FWD/AWD	350	6,9	5,5	G052182

Technical issues and repair guidelines

Generally, these gearboxes serve quite reliably for 2-5 years. The warranty of the automaker has been extended (only VW) up to five years. At this period the percentage of visitors to service centers is still quite high. Customers complain about the issues related to vibrations, kicks, jerking caused by the double-disk clutch, velocity sensors, chips in the gearbox that damage mechatronics.

First repairs of these sophisticated and highly-priced gearboxes are related to replacement of filters: external filters of heat exchanger and ATF, which should be changed with the external filter. Minor and repeated repair operations of DQ250 involve replacement of VFS solenoids, which get damaged by dirt from ATF and, as a result, lose their operating qualities related to changing the oil flow and its pressure. As a result, VFS solenoids become "rejected" by the control system. The reassembly of 02E -DQ250 gearbox with the replacement of rings, seals and filters is “a must” procedure to prolong the lifespan of its friction elements and solenoids.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A3	03-16	6 SP F/4WD	L4 1.8L 2.0L
Audi	Q3	13-16	6 SP F/4WD	L4 1.4L 2.0L
Audi	TT	98-16	6 SP F/4WD	L4 1.8L 2.0L V6 3.2L
Seat	ALHAMBRA	10-16	6 SP FWD	L4 1.4L 1.8L 2.0L
Seat	ALTEA	04-15	6 SP F/4WD	L4 1.9L 2.0L
Seat	LEON	05-16	6 SP FWD	L4 2.0L
Seat	TOLEDO	05-08	6 SP FWD	L4 1.8L 2.0L
Skoda	LAURA	05-13	6 SP FWD	L4 1.9L 2.0L
Skoda	OCTAVIA	04-16	6 SP F/4WD	L4 1.8L 2.0L
Skoda	SUPERB	08-16	6 SP F/4WD	L4 1.4L 1.8L 2.0L V6 3.6L
Skoda	YETI	09-16	6 SP 4WD	L4 1.8L 2.0L
Volkswagen	CADDY	04-16	6 SP F/4WD	L4 1.9L 2.0L
Volkswagen	CC	08-16	6 SP F/4WD	L4 2.0L V6 3.0L 3.6L
Volkswagen	EOS	06-15	6 SP FWD	L4 1.6L 2.0L V6 3.2L 3.6L
Volkswagen	GOLF	04-16	6 SP F/4WD	L4 1.4L 1.8L 2.0L
Volkswagen	GOLF PLUS	05-14	6 SP FWD	L4 2.0L
Volkswagen	GOLF SPORTSVAN	14-16	6 SP FWD	L4 2.0L
Volkswagen	JETTA	05-16	6 SP FWD	L4 1.6L 1.9L 2.0L L5 2.5L
Volkswagen	MAGOTAN	11-16	6 SP FWD	L4 1.8L 2.0L V6 3.0L
Volkswagen	NEW BEETLE	11-16	6 SP FWD	L4 2.0L
Volkswagen	PASSAT	05-16	6 SP F/4WD	L4 1.8L 2.0L V6 3.0L 3.2L 3.6L
Volkswagen	POLO	14-16	6 SP FWD	L4 2.0L
Volkswagen	SCIROCCO	08-16	6 SP FWD	L4 1.6L 1.8L 2.0L
Volkswagen	SHARAN	10-16	6 SP FWD	L4 1.4L 1.8L 2.0L
Volkswagen	TIGUAN	08-16	6 SP F/4WD	L4 1.4L 2.0L
Volkswagen	TOURAN	05-16	6 SP FWD	L4 1.4L 1.6L 1.8L 2.0L
Volkswagen	VENTO	14-16	6 SP FWD	L4 1.5L

How to repair this transmission (Videos)

Clutch Replace

VW Mechatronic Unit - DSG DQ250 02E

02E DSG Clutch Damage

VW and Audi DSG Clutch Upgrade

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Self-study programme 308 DQ250 02E
pdf	www.at-manuals.com	The 02E Direct Shift Gearbox Design and Function DQ250
web	www.at-manuals.com	Solenoids and pressure control valve locations and functions DQ250
pdf	www.at-manuals.com	Design and Function 02E DQ250

DQ200 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

This dual-clutch transmission is controlled with the use of electric motors instead of hydraulic valves of piston valves and the pump.This transmission uses the main tested advantage of mechanical gearboxes – the clutch is relocated to open space and wear products of clutches are immediately get out from the transmission without causing any harm. Neither planetary gears nor hydraulic switch control are used for this purpose.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DSG	FWD	250	1,7	1,7	G052512

Technical issues and repair guidelines

Gear shifting is implemented by two fork connectors controlled from a closed small hydraulic Mechatronic which may contain approx. 1 liter of ATF. This immediately reduced the cost of production at the expense of the transmission resource. Such transmissions cover 200 thousand kilometers with some problems. But at the same time advantages of this transmission are very attractive (high level of efficiency (up to 97%) and dynamics).

Repair and typical problems of DQ200

These transmissions are quite complex for repair, therefore replacement is more preferable option.

The most common problems are related to all new elements:

- The dual-clutch gets worn out early or unevenly in case of an aggressive driving style.

- The new electric oil pump breaks too early and frequently and operates in an abnormal fashion.

- Typical issues with operation of sensors.

- High oil pressure in Mechatronics units push out the oil with fatal consequences for the trasmission.

As a result, automakers had to modify the transmission and some separate units each 2-3 years, investing more and more financial resources in making the transmission more sophisticated and expensive and hope that the project DSG will pay off before releasing of 1 million transmissions. The most common problem that occurs in these transmissions (except clutches vibrations): damage of the shifting fork Reverse\6 (including bearing parts).

There are also different defects successfully fixed in services specialized in repairing DSG with a dry clutch. The repair process related to components of this transmission is quite complicated and therefore this option doesn’t have much support among car owners, especially when the engine resource comes to an end.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A1	10-16	7 SP FWD	L3 1.4L L4 1.4L 1.6L 1.8L
Audi	A3	07-16	7 SP FWD	L3 1.0L L4 1.2L 1.4L 1.6L 1.8L
Audi	Q1	16	7 SP FWD	L3 1.0L 1.4L L4 1.4L 1.6L
Audi	TT	11-16	7 SP FWD	L4 1.8L
Seat	ALTEA	08-15	7 SP FWD	L4 1.6L 1.8L
Seat	IBIZA	08-16	7 SP FWD	L4 1.2L 1.4L 1.6L
Seat	LEON	07-16	7 SP FWD	L3 1.0L L4 1.2L 1.4L 1.6L 1.8L
Seat	TOLEDO	12-16	7 SP FWD	L3 1.4L L4 1.4L 1.6L
Skoda	FABIA	10-16	7 SP FWD	L3 1.4L L4 1.2L 1.4L 1.6L
Skoda	OCTAVIA	08-16	7 SP FWD	L4 1.2L 1.4L 1.6L 1.8L
Skoda	RAPID	12-16	7 SP FWD	L3 1.0L L4 1.2L 1.4L 1.5L 1.6L
Skoda	RAPID SPACEBACK	13-16	7 SP FWD	L4 1.2L 1.4L 1.6L
Skoda	ROOMSTER	10-16	7 SP FWD	L4 1.2L 1.6L
Skoda	SUPERB	08-16	7 SP FWD	L4 1.4L 1.8L
Skoda	YETI	09-16	7 SP FWD	L4 1.2L 1.4L 1.8L
Volkswagen	BORA	10-16	7 SP FWD	L4 1.4L
Volkswagen	CADDY	10-16	7 SP FWD	L3 1.0L L4 1.4L 1.6L 2.0L
Volkswagen	CC	08-16	7 SP FWD	L4 1.4L 1.8L
Volkswagen	CROSS LAVIDA	14-16	7 SP FWD	L4 1.4L
Volkswagen	GOLF	07-16	7 SP FWD	L3 1.0L L4 1.2L 1.4L 1.6L
Volkswagen	GOLF PLUS	07-14	7 SP FWD	L4 1.2L 1.4L 1.6L 1.9L L5 2.5L
Volkswagen	GOLF SPORTSVAN	14-16	7 SP FWD	L4 1.2L 1.4L 1.6L
Volkswagen	GRAN LAVIDA	13-16	7 SP FWD	L4 1.4L
Volkswagen	GRAN SANTANA	15-16	7 SP FWD	L4 1.4L
Volkswagen	JETTA	08-16	7 SP FWD	L4 1.4L 1.6L 1.8L 1.9L 2.0L
Volkswagen	LAMANDO	14-16	7 SP FWD	L4 1.4L
Volkswagen	LAVIDA	09-16	7 SP FWD	L4 1.2L 1.4L 1.6L
Volkswagen	MAGOTAN	11-16	7 SP FWD	L4 1.4L 1.8L
Volkswagen	NEW BEETLE	11-16	7 SP FWD	L4 1.2L 1.4L 1.6L
Volkswagen	PASSAT	08-16	7 SP FWD	L4 1.4L 1.6L 1.8L
Volkswagen	POLO	07-16	7 SP FWD	L3 1.0L L4 1.2L 1.4L 1.6L 1.8L 2.0L
Volkswagen	SAGITAR	09-16	7 SP FWD	L4 1.4L
Volkswagen	SANTANA	14-16	7 SP FWD	L4 1.4L
Volkswagen	SCIROCCO	08-16	7 SP FWD	L4 1.4L
Volkswagen	SHARAN	10-11	7 SP FWD	L4 1.4L 1.8L
Volkswagen	TIGUAN	11-12	7 SP FWD	L4 1.4L 1.8L
Volkswagen	TOURAN	08-16	7 SP FWD	L4 1.4L 1.6L
Volkswagen	UP	14-16	7 SP FWD	L3 1.0L
Volkswagen	VENTO	13-16	7 SP FWD	L4 1.2L
Volkswagen	XL1	13-15	7 SP FWD	L2 0.8L

How to repair this transmission (Videos)

DSG7 P17BF error code solution from KINERGO

DQ200 Clutch Disassembly

Volkswagen improvements on clutch and mechatronic

DSG mehatronics replacement

DL501 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The rear-driven model of 7-speed DSG7 with "wet" clutch - DL501 has been installed on Audi Q5-Q7, A4 Allroad, A5 Cabriolet, A6-A7 since 2008. This gearbox is also named as OB5. It operates with engines up to V8 4.0l (diesel) and transmits the torque up to 550 Nm at maximum speed.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DCT	FWD/AWD	550	7,5	6,7	G 052 529 A2

Technical issues and repair guidelines

VAG DL501 (0B5) gearbox is structurally divided into two compartments - "mechanical" where the hypoid oil is used for mechanical gearboxes, and an "automatic" part with double clutch frictions and the valve body, where "intelligent" oil is used specially for DL501 - G 052 529 A2.

Typical problems

Chips from the drum harm both the filter and components of the gearbox, and the electrics. All gearboxes including 7-speed DL501 have issues with Mechatronics.The gearbox operation with metal chips in oil leads to rapid wear-out of solenoids. As far as the hardware of this gearbox is concerned, the main component to be replaced is the whole clutch drum.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A4	07-16	7 SP 4WD	L4 2.0L V6 3.0L V8 4.2L
Audi	A5	08-16	7 SP 4WD	L4 2.0L V6 3.0L 3.2L V8 4.2L
Audi	A5 SPORTBACK	09-16	7 SP 4WD	L4 2.0L V6 3.0L 3.2L
Audi	A6	11-16	7 SP F/4WD	L4 2.0L V6 2.8L 3.0L V8 4.0L
Audi	A7	10-16	7 SP F/4WD	L4 2.0L V6 2.5L 2.8L 3.0L V8 4.0L
Audi	Q5	08-16	7 SP 4WD	L4 2.0L V6 3.0L 3.2L
Porsche	MACAN	14-16	7 SP 4WD	L4 2.0L V6 3.0L 3.6L

How to repair this transmission (Videos)

DL501 Wet Dual Clutch

D6GF1 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automated transmission HYUNDAI-KIA D6GF1 has been produced since 2012. In fact, this transmission is adaptation of the automated transmission produced by LuK. This transmission is coupled with 2.0 liter engines. The maximum torque transmitting capacity reaches up to 270 Nm. This transmission was mainly installed in Kia Ceed JD (2012-2018).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	DCT	FWD	270	1,9	1,9	SAE 75W/85, API GL-4

Main problems:

- For some time after its release, the transmission had some malfunctions, but these issues were fixed;

- Manu drivers complain about jerks and delays while shifting gears;

- Some drivers had to deal with failures of even or odd gears;

- Sometimes the transmission gets stuck on some particular gear and fails to shift;

- Some car owners had to replace the clutch when the mileage reached 50 thousand kilometers;

- Price of original spare parts for this transmission is very high

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hyundai	VELOSTER	11-16	6 SP FWD	L4 1.6L
KIA	CEE'D	12-16	6 SP FWD	L4 1.6L

How to repair this transmission (Videos)

Kia Ceed 2012 Kia DCT

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme D6GF1
web	hvmanual.com	Specifications D6GF1

CFT23 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The constantly variable transmission (CVT) ZF CFT23 of the German manufacturer of auomatic transmissions with the trade name "Ecotronic" has been installed on Ford Focus, C-MAX with engines 1.6 - 1.8 liters since 2003 until 2008. Later more powerful CFT30 was developed for Ford vehicles with a 3-liter engine. This CVT had been installed before 2008 on powerful Taurus as well as on Ford Focus of European assembly. This CVT was also noticed on Mercury Sable. The “push” belt construction is used in СFT23 as in RE0F09A, /JF010E by Nissan instead of “pulling” belt used in 01J CVT (Audi).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	170	8,9		WSS-M2C928-A

Technical issues and repair guidelines

But in more powerful CFT30 the belt did not cope with loads (similar to problems of Nissan Murano), therefore the pulling belt was applied here as in the variator 01J.

Original spare parts for repair of these CVT (produced by ZF) are basically neither produced nor sold. It is almost impossible to get even used spare parts for repair of CFT. Therefore the most popular spare parts for repair of CVT CFT23 are filter and repair kit of gaskets and seals. Experienced specialists in repair services recommend to change the whole kit of rubber gaskets and seals as well as filter and oil without waiting for problems with surfaces of cones after 3-4 years of intensive operation. The belt is produced by only one company and similar to other CVTs with pushing belt. Friction clutches F and steel discs used in this transmission are the same as for ZF 5HP24/30/19.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	FOCUS	04-08	CVT FWD	L4 1.6L 1.8L
Ford	FOCUS C-MAX	04-08	CVT FWD	L4 1.6L 1.8L

How to repair this transmission (Videos)

CFT30 Rebuild

CFT30

cft30 cft23

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout CFT30
pdf	Sonnax	Vacuum test CFT30

BVLA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

BVLA is 5-speed automatic transmission produced by Honda. This transmission is often installed in Honda Pilot.

Honda Pilot; 05-07; V6 3.5L (J35Z4); ATF Capacity/Change: 8.7/8.3 3.9/3.7

BVLA transmission may have some problems in case of accelerations higher than 160 km/h, especially when dealing with poor road surface. This problem may lead to the overheating or oil starvation. Transmission specialists recommend warming up transmission before driving, including summer-time, monitor the oil level and timely perform diagnostic checks.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Honda	PILOT	6	5 SP FWD	V6 3.5L

U440E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The U440E unit was designed by Aisin Co in 1999 for small FWD cars Toyota Yariz, Witz and Corolla with 1.3-liter capacity, which replaced the AW60-40 unit. This gear shifting solution usually can be found on the Japanese market of right-hand drive vehicles. The U340 unit produced simultaneously with U440E was chosen by Toyota for Corolla with the engine capacity of 1.5 liters and higher. The U540E unit more known as AQ4 is a quite rare solution for Daihatsu with more simple complete set. This gearbox is also used for American small cars Cadillac, Buick, Ford and Chinese Donfeng, Landwind under names AW80-40LS and AW81-40LS.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	150	5,8	2,1	Toyota Type T-IV

Technical issues and repair guidelines

The repair of this transmission is usually performed for cars with high mileage and already worn-out torque converter lockup unit. Each 4-th case of the rebuilding of this robust unit requires MasterKit – complete kit of spare parts. After the exhaustion of resource of this transmission (and rings wear-out), the first component to be worn is a set of frictions with steel discs in the clutch package Direct. After that, С1 Forward and Overdrive frictions get worn and then others.

The "soft spot" of AW81-40 components is considered to be the planetary gear, which even during testing required some servicing before covering 100 thousand kilometers. The reason is related to design issues. The transmission of maximum operating torque via the gear to the differential by means of strong side loads leads to the damage of units in this package. (Only paired with 1.6 liter engines). The major wear-out of friction units and consequent damage of the pump bushing takes place when neglecting the oil pressure parameters and wear-out of the torque converter.

As for electrical components, standard cleaning and valve body reassembly, repair specialists order EPC and On-Off solenoids. Sometimes the differential is also ordered for the overhaul. In old cars, specialist often install external fine filter. The filter helps to preserve clean ATF and decreases wear-out of friction components.

The spare parts resource will be significantly increased, if ATF is kept clean and the torque converter gets repaired after covering 150- 200 thousand kilometers (depending on the car type and driving style) and preventive cleaning of the valve body and solenoids. More often problems occur in cars with engines capacity equal to 1.3. The torque of these engines turns out to be too high for this automatic unit and electronic control allows the driver to load the transmission to the maximum. Careful usage of cars with this gearbox without fast accelerations from traffic lights and slipping on deep snow allows postponing first overhauls of this “invincible” gearbox for 6 or more years.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Beijingauto	E-SERIES	12-16	4 SP FWD	L4 1.3L 1.5L
Changan	CD101	12	4 SP FWD	L4 2.0L
Changan	CX20	10-16	4 SP FWD	L4 1.3L
Changan	JOICE	07-12	4 SP FWD	L4 1.6L 2.0L
Changan	V805	10-12	4 SP FWD	L4 1.6L
Changan	YUEXIANG	09-14	4 SP FWD	L4 1.5L
Changan	YUEXIANG V5	12-16	4 SP FWD	L4 1.5L
Changan	Z-SHINE	08-12	4 SP FWD	L4 1.5L 1.6L 1.8L 2.0L
Dongfeng	A30	14-16	4 SP FWD	L4 1.5L
Dongfeng	BFX	11	4 SP FWD	L4 1.6L
Dongfeng	H30	10-16	4 SP FWD	L4 1.5L 1.6L
Dongfeng	JOYEAR	16	4 SP FWD	L4 1.5L
Dongfeng	S30	09-16	4 SP FWD	L4 1.5L 1.6L
Ford	FIESTA	97-16	4 SP FWD	L4 1.6L
Ford	FUSION	06-12	4 SP F/4WD	L4 1.6L
Gonow	E MEI	14-16	4 SP FWD	L4 1.6L
Land-Wind	B102 HB / B103 NB	11-12	4 SP FWD	L4 1.6L
Land-Wind	E101	11-12	4 SP FWD	L4 2.0L
Land-Wind	FENGSHANG	06-10	4 SP FWD	L4 2.0L
Opel / Vauxhall	AGILA	08-14	4 SP FWD	L3 1.0L L4 1.2L
Suzuki	ALTO	15-16	4 SP FWD	L3 1.0L
Suzuki	BALENO	00-08	4 SP FWD	L4 1.5L
Suzuki	SPLASH	08-14	4 SP FWD	L4 1.2L
Suzuki	SWIFT	97-16	4 SP FWD	L4 1.2L 1.3L 1.4L 1.5L 1.6L
Toyota	YARIS	12-13	4 SP FWD	L4 1.5L

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme U440E
web	www.at-manuals.com	Check Balls U440E
web	www.at-manuals.com	Stall test U440E

AW45043LE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The rare 4-speed automatic transmission AW450-43LE had been installed since 1998 until 2007 on the RWD model ISUZU NPR/ NQR. with engines capacity of appr. 5 liters. In terms of design, this transmission is similar to AW442F. In most cases Isuzu models come to repair shops with the purpose of fixing the transmission.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		12,5	6	Type T-IV

Technical issues and repair guidelines

This transmission for RWD vehicles is very reliable as all Aisin transmissions with high torque capacity. In most cases, problems occur in old vehicles and mainly associated with their age. If the car owner keeps track of the thermostat condition, then the lifespan of the automatic transmission AW450-43LE can exceed the service life of the car itself.

The torque converter is the first component to get out of order in this transmission, then it leads problems with the worn-out oil pump and bushings. The repair kit of gaskets and seals is included in the common order for a complete reassembly of this transmission. Rare repair cases usually include replacement of the Direct package. In most cases friction friction components of this package are the first to get burnt because of high loads. Frequently, this transmission comes to the repair shop completely burnt friction elements. In such cases, specialists order a full kit of frictions as well as the kit of steel discs.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Isuzu	ELF	97-15	4 SP R/4WD	L4 3.1L 4.6L
Isuzu	TRUCK NPR	99-07	4 SP RWD	L4 4.75L 5.2L DIESEL
Mazda	TITAN	04-15	4 SP R/4WD	L4 3.1L
UD Trucks	CONDOR	97-14	4 SP R/4WD	L4 3.1L 4.6L

How to repair this transmission (Videos)

450-43LE Teardown

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout AW45043LE

AD4 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic transmission AD-4, AD-8 is a French modification of the 01M (01P) unit. The AD-4 is intended for engines up to 2 liters and may be installed on FWD Laguna, Megan and Clio from Renault. The AD-8 modification was released a bit earlier for Safrane and Espace with 3 liter engines V6 produced in 1989-1998. Both transmissions are quite reliable and rarely met in repair services. Friction components for AD-4 are interchangeable with parts for the 01M.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		5,7	3,5-4	Dexron III

Technical issues and repair guidelines

Overhauls ofd this automatic transmission consist of the reassembly and cleaning of the transmission with replacement of seals and gaskets. Sometimes specialists replace friction componeand solenoids.

Specialists order the following for repair procedures:

- individual filter for AD-4 Megan

- individual filter for AD-4 Clio and Scenic

- filter AD-8

- repair kits of gaskets and seals, AD-4 frictions, which are interchangeable with parts for German transmission. Frictions for AD-8 are selected separately taking into account size and quantity:

- Kit of pistons AD4\AD8 consisting of 5 pieces.

This transmission is quite simple and repairable, after a proper repair it operates for a long period of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Renault	MEGANE	0	4 SP FWD	L4 1.6L

Instruction manuals and useful links

Link type	Source	Description
pdf	dogacelektronik.com	Fault finding AD4, AR4

A8LR1 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 8-speed RWD automatic transmissions A8LR1, A8TR1 (4WD) with longitudinal positioning designed by Hyundai were installed on luxury cars with engines from V6 3.0 up to V8 5.0L since 2011. This transmission was launched in production in 2010 and after several years of testing on the Korean market, Hyundai engineers introduced some updates, which improved some hard parts and frictions. Some electrical mechanisms and computer settings were also changed.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
8	AT	RWD/AWD	500	9.6		ULTRA ATF SP-IV RR

Technical issues and repair guidelines

These transmissions rarely get in repair services, because of reliable rear drive construction which operates properly for the first 4-5 years of service without serious problems.

Ravenol SP-IV RR fluid is used for these finely adjusted transmissions. Specialists do not recommend using other types of fluid, because the oil in this transmission performs many other functions in addition to lubrication, cooling and hydraulic environment. Although the oil ageing slightly worsens its qualities, after running 80-100 thousand kilometers it is recommended to check it for transparency and change it together with the filter-pan, especially if the transmission operated at maximum loads.

One of the main soft spots causing problems in this transmission is the valve body with solenoids. This transmission is very sensitive to operation with contaminated oil under the condition of ultimate loads. Intensively operating VFS solenoids-electric-regulators are the first to reach the end of their lifespan.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hyundai	EQUUS	11-16	8 SP RWD	V6 3.0L 3.8L
Hyundai	GENESIS	11-16	8 SP R/4WD	V6 3.0L 3.3L 3.8L
Hyundai	GENESIS COUPE	11-16	8 SP RWD	L4 2.0L V6 3.8L
KIA	K9	12-16	8 SP RWD	V6 3.3L 3.8L
KIA	QUORIS	13-16	8 SP RWD	V6 3.3L 3.8L

How to repair this transmission (Videos)

Hyundai's new 8-Speed Automatic Transmission

Instruction manuals and useful links

Link type	Source	Description
pdf	drive.google.com	KIA A8LR1 Service information

9HP48 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

9 speed transverse ZF 9HP48 for the front drive was released in 2013 at two factories: in Saarbrücken for Europe and by Chrysler in Kokomo (USA) for Japanese and American cars - Honda and Chrysler. Both versions have significant differences in the range of spare parts and major components because Chrysler made plenty of changes in its version . It was tested on the American market and there were mostly problems with computer settings and electrics. ZF9HP48 is designed to transfer the torque from the engine up to 480 Nm, but as all transmissions with transverse positioning it is much less endurable to extreme stress and therefore it is installed on urban jeeps.9 gears are only required when the vehicle passes half a day at the 1st gear in urban traffic and when out of traffic it immediately gets on the freeway where the 9th gear serves to save fuel.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
9	AT	FWD	480	7.5	4	ZF Lifeguardfluid 9

Technical issues and repair guidelines

Rebuilding of a transmission is always made with a repair kit consisting of gaskets and seals (overhaul kit). In this case the filter is replaced as well .Prolonged driving with contaminated oil and worn-out sealing rings leads to rapid wear of solenoids, which operate evenly as a group and also a group fail around the same time period. But it actually requires a long time to have the solenoids fully unconditional.

ATF change is quite difficult and requires experience in automatic transmissions, especially with the 6-speed and 8-speed ZF automatics. Smell of burnt ATF or presence of metal grit of around 1mm is considered to be an indicator for a major overhaul of the automatic transmission even if the gearbox runs flawlessly.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Acura	MDX	14-16	9 SP 4WD	V6 3.0L 3.5L
Acura	RLX	16	9 SP FWD	V6 3.5L
Acura	TL	14-16	9 SP F/4WD	V6 3.5L
Chrysler	200	14-16	9 SP F/4WD	L4 2.4L V6 3.6L
Chrysler	TOWN & COUNTRY	16	9 SP FWD	V6 3.6L
Chrysler	TOWN & COUNTRY	16	9 SP FWD	L4 2.8L V6 3.6L
Dodge	DART	15-16	9 SP FWD	L4 1.4L 2.0L 2.4L
Dodge	PROMASTER CITY	14-16	9 SP FWD	L4 2.4L
Fiat	500X	14-16	9 SP 4WD	L4 1.4L 2.0L 2.4L
Honda	CIVIC	14-16	9 SP FWD	L3 1.2L L4 1.6L
Honda	CR-V	15-16	9 SP 4WD	L4 1.6L
Honda	ODYSSEY	16	9 SP FWD	V6 3.5L
Honda	PILOT	15-16	9 SP F/4WD	V6 3.5L
JEEP	CHEROKEE	13-16	9 SP F/4WD	L4 2.0L 2.4L V6 3.2L 3.6L
JEEP	RENEGADE	14-16	9 SP F/4WD	L4 1.4L 2.0L 2.4L
Land-Rover	DISCOVERY SPORT	14-16	9 SP 4WD	L4 2.0L 2.2L
Land-Rover	RANGE ROVER EVOQUE	13-16	9 SP F/4WD	L4 2.0L 2.2L

How to repair this transmission (Videos)

9HP 9-speed transmission

9HP Transaxle Operation - Part 1 of 2

9HP Transaxle Operation - Part 2 of 2

ZF 9HP48 and Chrysler 948TE

Instruction manuals and useful links

Link type	Source	Description
pdf	Atra	Introduction 9HP48/948TE
web	Wikipedia	ZF 9HP transmission
web	gearsmagazine.com	Chrysler’s 948TE
pdf	fzth.de	Scheme 948TE

8L90 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The RWD automatic transmissions with longitudinal positioning Hydra-Matic 8L90 (M5U) and 8L45 (M5N, M5T) were designed in 2015 for Cadillac CT6 with new engines (3.6 liters) and also suitable for 6-liter engines V8. The design of this modern transmission is similar to 8HP by ZF and has a lot of same "features", like Start-Stop system on at traffic lights, used to save more fuel.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
8	AT	RWD/AWD	1000	11,7	6	Dexron HP

Technical issues and repair guidelines

The transmissions has much higher reserve on components than its German competitor and should operate at least 200-300 thousand kilometers before the first overhaul ( under the condition of well-timed ATF change). In case of frequent “kickdown” usage with a switch-on of controlled slipping of the lock-up clutch, the wear-out of friction elements occurs quite rapidly and contaminates the valve body, fluid and filter. The filter is made of plastic with a two-layer felt membrane and its better to change this part in a timely manner.

The oil and filter should be changed when there are any suspicions related to oil transparency. Such situations may occur after travelling 40 thousand kilometers or 80 thousand kilometers depending on driving style and adherance to the transmission warm-up rule before driving in winter time. Removal of the pan allow specialists to estimate the level of components wear-out and valve body contamination.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Cadillac	ATS	15-16	8 SP RWD	V6 3.6L
Cadillac	CT6	15-16	8 SP 4WD	V6 3.0L
Cadillac	CTS	15-16	8 SP RWD	V8 6.2L
Cadillac	ESCALADE	15-16	8 SP R/4WD	V8 6.2L
Cadillac	ESCALADE ESV	15-16	8 SP R/4WD	V8 6.2L
Chevrolet/GM	CAMARO	15-16	8 SP RWD	V8 6.2L
Chevrolet/GM	CORVETTE	14-16	8 SP RWD	V8 6.2L
Chevrolet/GM	SIERRA	14-16	8 SP R/4WD	V8 6.2L
Chevrolet/GM	SILVERADO	14-16	8 SP R/4WD	V8 5.3L 6.2L
Chevrolet/GM	YUKON XL	06-16	8 SP R/4WD	V8 6.0L 6.2L

How to repair this transmission (Videos)

TransTec 8L45 Teardown

Valve Body Disassembly

8L90 Case Disassembly

8L90 assembly

Instruction manuals and useful links

Link type	Source	Description
pdf	Atra	Introduction 8L90
web	gmauthority.com	Specification 8L90
web	sandyblogs.com	Harsh Shifting on the 8L90
web	sandyblogs.com	Reprogramming Procedures for the 8L90
web	sandyblogs.com	All-New 8L90 8-Speed info

9T50 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 9-speed automatic transmission Hydra-Matic 9T50 for front-wheel drive vehicles was designed by GM and was officially showcased in December 2016. This transmission was intended to replace its 6-speed predecessor. According to GM engineers, the 9T50 transmission allows striking a balance between high dynamic parameters and fuel economy. The size of this transmission is the same as the size of its 6-speed predecessor, but the Hydra-Matic 9T50 also supports start/stop technology and has a new torque converter.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
9	AT	FWD/AWD	380	10	6,3	Dexron HP

One of the peculiarities of this transmission is a selective clutch, which may disconnect the transmission from the engine and operate in the rundown mode. The first car to operate with this transmission was Chevrolet Malibu. The first gear of the 9T50 transmission is very short (gear ratio is 4.69), so the car can move very smoothly from a standstill. The 9-th gear is designed for economical and more relaxed driving (gear ratio is 0,62).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	EXCELLE GT	15-16	9 SP FWD	L4 2.0L
Buick	LACROSSE	16	9 SP F/4WD	V6 3.6L

Instruction manuals and useful links

Link type	Source	Description
pdf	sandyblogs.com	TechLink 9T50

7DCL750 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 7DCL750 7-speed dual-clutch transmission was designed by Getrag for transaxle and mid-engine positioning in sports vehicles with RWD or AWD.

The 7DCL750 has an optimal installation length, which became possible thanks to a 4-shaft structure. The ratio of 1-st gear, 7-th gear and final drive can be defined and adopted to the respective usage. This transmission also may have a mechanically or electronically-operated differential locking device. The dry-sump lubrication system helps to enhance the level of efficiency and fuel consumption. In addition, this system also helps to keep to minimum windage losses

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DCT	RWD	750	7,8	3,5	DCTF105786

Typical problems:

Mechanical friction suspension from hot ATF clogs valves of the valve body and solenoids, then it appears on friction surfaces and contributes to wear, vibrations and sticking of valves, especially when the friction layer is worn down to the glue basis. It leads to the chain reaction of metal wear and further contamination of ATF. Thus, DSG transmissions are equipped with outside filters of high capacity. Getrag engineers recommend changing this filter more often, especially if the transmission is old.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ferrari	CALIFORNIA	08-16	7 SP RWD	V8 4.3L
Ferrari	F12	12-16	7 SP RWD	V12 6.3L
Ferrari	F458	09-15	7 SP RWD	V8 4.5L
Ferrari	F488	15-16	7 SP RWD	V8 3.9L
Ferrari	F599 GTB	09-11	7 SP R/4WD	V12 6.0L
Ferrari	F612	10-11	7 SP R/4WD	V12 5.7L
Ferrari	FF	11-16	7 SP 4WD	V12 6.3L
Ferrari	LAFERRARI	13-15	7 SP RWD	V12 6.3L
Ford	GT	16	7 SP RWD	V6 3.5L
Mercedes-Benz	GT	14-16	7 SP RWD	V8 4.0L
Mercedes-Benz	SLS	10-14	7 SP RWD	V8 6.3L

How to repair this transmission (Videos)

Ferrari 458 Getrag Double Clutch Transmission Fix

Instruction manuals and useful links

Link type	Source	Description
pdf	getrag.com	Press information 7DCL750
pdf	getrag.com	Technical data 7DCL750

7DCT300 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 7-speed automatic transmission PowerShift 7DCT300 was manufactured by Getrag. This transmission with 2 clutches is intended for front-wheel drive cars with the engine east-west mounting. The design of this transmission successfully combines two multiple-disc clutches and electro-hydraulic gearbox actuators. The 7DCT300 is designed on the basis of the 6-speed PowerShift 6DCT250. The basic design of the transmission is implemented according to the three shaft configuration. At the same time the total weight of the transmission was reduced from 72 to 67kg. The development of the improved design was made because of more severe requirements for fuel economy, dynamics and environmental compatibility of cars.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	DCT	RWD		2,1	1,8	DCTF105786

Designed on a modular platform, the 7DCT300 transmission is intended for engines with the torque capacity up to 300 Nm. Engineers of this transmission solution think that the most remarkable feature of this transmission is an intelligent power transmission system Smart Actuation. This system facilitated to reducing the powertrain power consumption to 40 volt and made this transmission more efficient. Electric actuators, as a part of the transmission control mechanisms, can operate with the non-running engine and when the car is not moving. The electronic transmission control unit (TCU) is mounted on the transmission case. By means of the wiring harness, the TCU is connected to 5 electric motors, 2 speed sensors, oil temperature sensors, sensor of engaged gear and two pressure sensors in clutch actuators. The TCU software was designed taking into account demands of 23 automakers using Getrag transmissions with 2 clutches. Usually, the transmission is equipped with the open-type differential, so the oil filling operation is performed when the transmission is installed on the car and when the wheel drives are mounted. However, at the request of the car manufacturer, the PowerShift 7DCT300 may be equipped the differential of the closed type. Currently, dual-clutch transmissions produced by Getrag are installed on such cars as Ford Focus, Ford Galaxy, Renault Clio RS, Honda-Acura, Ferrari 458 Speciale, BMW-M, Volvo, Qoros.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	ECOSPORT	16	7 SP FWD	L3 1.5L

How to repair this transmission (Videos)

GETRAG 7DCT300

Instruction manuals and useful links

Link type	Source	Description
pdf	getrag.com	7DCT300 general information
video	getrag.com	7DCT300 Product animation

6L45 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The Hydra-Matic range 6L45 - ... 6L90 is the second generation of modular-type 6-speed automatic transmissions, used for RWD vehicles. The 6L80 and 6L90 were the first automatic gearboxes of the Heavy-duty class designed in 2005. Next year 6L50 \6L45 gearboxes of the Medium-Duty class (with a lower torque) up to 450 Nm replaced BMW gearbox, which was popular in repair services. The 6L45E (GA6L45R) is a constructively modified 5L40 (which was actually replaced by the 6L45E in 2007 ). Mainly used with budgetary BMW-3 and X3 with engines 2.5l - 3.0L. 6L50, 6L80 and 6L90 transmissions may be considered as quite reliable RWD 6-speed gearboxes of GM series. European modifications 6L45 /R have been used since 2006 on BMW Х1, Х3 of 1-st 3-rd and 5-th series and manufactured in Strasbourg, France. These gearboxes mainly differ in electrical components.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD	450	9,8	6,2	Mercon SP

These gearboxes usually get in repair services for scheduled ATF change, replacement of the filters with the pan gasket. ATF gets contaminated because of aggressive accelerations and wear-out of the lock-up clutch. It is recommended to change ATF in accordance with its contamination level, but no later than after travelling 80 thousand kilometers.

Typical problems

The problem detected on the 6L80 (manufactured before 2008) is related to the design of the pump cover and cranking of filler rings resulting in problems with shifting from the 2-nd to the 3-rd gear and delays in switch-on of Forward or Reverse gears.

In case of the overhaul, it is recommended to check the leak integrity of the drum 555. There may be some hidden cracks leading to the operation pressure losses in packs causing problems when shifting gears 2-3 and Reverse. Overheating is dangerous for all pistons, which have to be fully replaced. It is the problem inherited from its 5-speed predecessor 5L40E.

All pistons and retainers are replaced quite frequently (kit of pistons 6L45-50). Problems with the torque converter (TC) may also occur in these gearboxes. The wheel-hub early gets out of order. Rare and complicated cases of the overhaul show some vulnerability of the pack (4-5-6 Clutch), which in neglected cases leads to burning of all frictions, including steel discs and pistons. The reason is often related to wear-out of the TC bushing and TC itself.

The torque converter is often considered to be a soft spot in American gearboxes. After 100-150 thousand kilometers (depending on engine and driving style), it is recommended to test the TC seal for leaks. When there are leakages in the seal or ATF gets rapidly contaminated, then it is desirable to get TC in repair services to prevent problems with the pump or the valve body. This measure particularly should be applied when automatic gearboxes operate jointly with motors (with maximum torques).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
BMW	5-SERIES	06-10	6 SP R/4WD	L6 2.5L 3.0L
BMW	6 SERIES	07-13	6 SP RWD	L6 3.0L
BMW	Z4 ROADSTER	09-11	6 SP R/4WD	L6 3.0L

How to repair this transmission (Videos)

Disassembly

Manual Valve

6L90, building the tehcm pressure switches

6L80-E Transmission Repair

6L80E Teardown Inspection

6L80E Valvebody

GM 6L80 E Transmission - No Forward

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme 6L45
pdf	Sonnax	Valve Body Layout GM 6L45, 6L50, 6L80, 6L90
pdf	Sonnax	Vacuum test 6L45, 6L50, 6L80, 6L90
web	Sonnax	6L80 Family Identification Guide
web	Sonnax	Location and Function of New #8 Checkball for 6L80/90
web	Sonnax	6L80/6L90 "No Movement" After Repair
video	Sonnax	6L80 Series Transmission Upgrades & Repairs

6DCT250 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6DCT250 6-speed transmission has been developed for front-transverse installation in medium and compact cars with the torque capacity up to 280 Nm. This transmission is equipped with a dual wet clutch. Currently, this transmission is installed in almost all Ford models.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	DCT	FWD		1,8	1,8	75w90

A smooth gear shifting is ensured thanks to the parallel operation of two main shafts, actuated by the clutch system. In practice, it is implemented in the following way: one clutch selects the necessary gear, while the other one prepares the next gear for engagement. It is worth mentioning that the gear shifting process in the 6DCT250 transmission rules out the possibility of torque losses. In other words, the automatic transmission successfully combines all conveniences of automatic transmissions and the efficiency of manual transmissions. This transmission may have a separate PTU with AWD system, as well as a start-/stop feature without modification of the hardware. Combined with an E-motor, the gearbox may also be applied in a hybrid drive.

Peculiarities of operation:

In terms of design, this transmission is a nonstandard solution, which specifies special requirements for the maintenance and operation of the vehicle:

- When stopping the car, the driver has to press the brake pedal, using the handbrake lever, and only then shit to “P” parking position;

- When using the vehicle in the "Select-Shift" mode, the driver should not keep the button “+/-“ pressed;

-When the engine runs idly, the driver should switch the selector into “P” (parking) or into “N” (neutral) mode;

- When selecting “R” (reverse), “S” (sport), or “D” (drive) mode, it is not recommended to keep the brakes engaged for a long time;

- Transmission repair specialists recommend changing of ATF and filter after each 45 thousand kilometers. It is important that this procedure should be performed at special services.

Problems

The most common faults in the 6DCT250 Powershift transmission are related to the clutch system. Due to structural stiffness, this transmission component responds to ECU malfunctions, which may lead to wedging and gear failure. In some cases specialists detect ATF leakages in the primary shaft seal. The ATF appearance on the clutch may lead to slippage.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	B-MAX	12-16	6 SP FWD	L4 1.5L 1.6L
Ford	C-MAX	14-16	6 SP FWD	L4 1.5L
Ford	FIESTA	10-16	6 SP FWD	L3 1.0L L4 1.2L 1.5L 1.6L
Ford	FOCUS	11-16	6 SP FWD	L3 1.5L L4 1.5L 1.6L 2.0L
Ford	TRANSIT COURIER	15-16	6 SP FWD	L4 1.6L

How to repair this transmission (Videos)

Ford Dual Clutch Transaxle (DCT) DPS6

DPS6 Transmission Teardown

DPS6 Internal Operation

Slipping/Shudder Clutch replacement

Dual Clutch Transmission Clutch Assembly Removal and Installation Guide

Instruction manuals and useful links

Link type	Source	Description
pdf	www.getrag.com	Specifications 6DCT250
pdf	getrag.com	Press information 6DCT250
pdf	automaticchoice	Scheme 6DCT250

4L85E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic transmission 4L85E was firstly presented in 2001 together with powerful engines Duramax V8 (with torque reaching up to 650 Nm). This transmission was installed only on large SUVs, pickups and minibuses. This transmission is very powerful and can be applied cars which take part in off-road racing, drag racing or custom street driving.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/4WD	650	13,6		Dexron VI

These transmissions have issues with early style 12 pin harnesses in which transmission fluid leaks around the harness and shorts the pinouts causing transmission to go into "limp mode" (some manuals say "limp home mode"). This issue can be easily rectified by simply cleaning the plug

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	VAN FULL SIZE 3500	95-09	4 SP RWD	V6 4.3L V8 4.8L 5.7L 6.0L 7.4L 8.1L 6.5L 6.6L DIESEL

4L40E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 4L40E produced by GM found application on the most common BMW 318 (since 1998). This automatic transmission was designed on the constructive basis of a reliable 4L60E, but were produced in Europe for the Bavarian automobile factory. This range of automatic transmissions replaced the 4-speed 4L30E and had been in production until 2007, when GM replaced these transmissions with the 6-speed 6L45. In terms of design the 4L40E (5L40) is the most simple, robust and reasonably priced transmission.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	360	9	5,5-6	Dexron VI

Technical issues and repair guidelines

The repair of this transmission mainly lies in the replacement of filter, gaskets and seals (preventing oil leakage), and replacement of burnt friction elements. All parts are interchangeable with 5L40E and 5L50E. Frictions are one-sided as in the popular DP0 transmission. The pack (Direct Clutch; 2nd Coast) burns twice as frequently as other clutch packs.Generally, this gearbox is considered to be reliable and almost “invincible”, when avoiding heavy ATF contamination by friction dust and the abradant which wears out not only friction nodes, but also the valve body.

This issue (oil contamination) often results in self-regulating pump becoming “unregulated”, also remaining in the mode of ultimate capacity. It leads to the rapid gear-shifting as well as to increased pressure in packages resulting in pistons damage. Issues with pistons is a typical soft spot for the 5-speed 5L40E and 5L50E (BMW Х5). The rubber-covered piston (forward) most commonly gets out of order because of its design peculiarities.It is usually recommended to take care about the ATF quality for this transmission.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
BMW	3-SERIES	00-05	4 SP RWD	L4 1.9L L6 2.0L 2.8L

How to repair this transmission (Videos)

Part 1 Transmission Service

Part 2 Transmission Service

Instruction manuals and useful links

Link type	Source	Description
pdf	shinseiauto.com	Scheme 4L40E

2ML70 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 2ML70 gearbox is a 4-speed rear drive which can be configured in a two or four wheel drive application. The secret of this transmission lies in combination of 2 electric motors inside the transmission, which serve not only for driving the car under certain conditions, but also for starting the engine. The 2ML70 transmission has several important advantages when compared to its gasoline counterparts: reduced fuel consumption, improved performance characteristics, reduced amount of toxic emissions.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	Hybrid System	RWD	515	12.3	10.8	Dexron VI

This transmission doesn’t have a torque converter. It is equipped with stop/start technology and therefore has a 12 volt auxiliary pump to keep the 1-2 clutch primed any time the engine shuts down. The design of 2ML70 also includes 3 planetary gear sets, 2 rotating clutch packs and 2 fixed clutch packs. The gearbox functioning is controlled by a Transmission Control Module (TCM) which is located inside the transmission and the hybrid systems operation is controlled by the Hybrid Control Processor (HCP) located under the hood.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
BMW	X6	09-14	EVT 4WD	V8 4.4L
Cadillac	ESCALADE HYBRID	07-13	EVT R/4WD	V8 6.0L
Chevrolet/GM	SILVERADO HYBRID/SIERRA HYBRID	09-13	CVT R/4WD	V8 6.0L
Chevrolet/GM	TAHOE HYBRID	07-13	CVT R/4WD	V8 6.0L
Chevrolet/GM	YUKON HYBRID	08-13	EVT R/4WD	V8 6.0L
Chrysler	ASPEN HYBRID	9	CVT R/4WD	V8 5.7L HEMI
Dodge	DURANGO HYBRID	9	EVT R/4WD	V8 5.7L HEMI
Mercedes-Benz	R CLASS	09-11	CVT R/4WD	V6 3.5L

How to repair this transmission (Videos)

GM Two Mode Hybrid

What is a two-mode hybrid?

Instruction manuals and useful links

Link type	Source	Description
web	www.searchautoparts.com	AN INTRODUCTION TO GM'S 2ML70 TWO MODE HYBRID TRANSMISSION
pdf	www.atraonline.com	2ML70 (RPO M99)

10R80 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 10R80 is a 10-speed automatic gearbox designed thanks to fruitful cooperation between Ford and GM (10L90). Both companies pointed out the fact that while the mechanical part of the gearbox was developed collaboratively, the software part of the 10R80 will be different for each manufacturer and, as a result, their corresponding powertrain structures should not necessarily resemble each other in view of gear shifting algorithms. This transmission has 10 forward gears, three of which are overdrive ratios. It's deep 4.69 to 1 first gear ratio is the lowest in its class and it features a relatively tall 0.63 to 1 final overdrive ratio.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
10	AT	RWD/4WD	800	12.9	8	Motorcraft ULV

A built-in electrohydraulic pump ensures that the "start-stop" feature operates with minimal delay. The 10R80 includes 3 operation modes - "Tow Haul", "Sport", and "Normal", with each mode changing the gear shifting algorithm and characteristics to compliment particular forms of driving behavior. Since the gearbox has 10 forward gears, its running characteristics and, more importantly, fuel efficiency is maximized by the transmission's capacity to get a suitable ratio for current operating conditions, such as engine speed, load, and car speed. This transmission became a standard option for the 2017 F-150 equipped with the 3.5L Eco-Boost engine.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	F-150	16	10 SP R/4WD	V6 3.5L V8 5.0L
Ford	F-150 SUPERCREW	16	10 SP R/4WD	V8 5.0L
Ford	MUSTANG	16	10 SP RWD	L4 2.3L V8 5.0L

How to repair this transmission (Videos)

10-speed Transmission Assembly

Instruction manuals and useful links

Link type	Source	Description
web	www.f150hub.com	0R80 10 SPEED AUTOMATIC TRANSMISSION RATIOS

3HP22 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

3-speed automatic transmission 3HP22 was produced by ZF company in 1973. This transmission was intended for rear drive passenger vehicles with motors M10, M20, M30 of BMW product range (big coupes and sedans, 3, 5, 6 and 7 series). This automatic transmission transmits the torque up to 320 Nm.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD	320	2.4	2	Dexron II

Technical issues and repair guidelines

One of the most common sources of problems in this 3HP22 transmission is the governor. The governor is a shifting pressure regulator on the output shaft of the transmission. The gear shifting point according to the car speed depends on the above mentioned governor.The wear-out of niches for plastic rings on the hub of the last transmission clutch is considered to be another soft spot. This problem also may lead to the governor pressure loss.

How to repair this transmission (Videos)

3HP22 valve body rebuild

Instruction manuals and useful links

Link type	Source	Description
web	wikipedia	ZF 3HP22 transmission

Transmission Leak Test Unit Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Leak test units allow checking circuit integrity for transmission units through use of hydraulic pressure. These tools guarantee time saving since modern models do not require removal of the transmissions off vehicles. It is a universal machine which merely requires appropriate leak test plate to fit any automatic gearbox. The 4L60 transmission, 4L80 transmission, ZF transmissions are some of the most demanded for this transmission service.

The answer to the question on the reason of oil flowing out of the transmission troubles many transmission specialists. Transmissions oil leakage is in the group of problems with which almost every driver ever found. Under the car there are oil stains that are gradually increased. Set of lubricants is considered to be an important part of the vehicle. Such a problem leads to major failures. Friction of the contacting parts goes uncontrolled, wear debris is stopped from leaving the drivetrain, the assembly doesn’t cool down. It is unsafe and could cause fire.

Various leaks at the junction of gearbox and engine most likely can occur due to the following reasons: wear-out or failure of seals, various defects in shafts and seals, emergence and increase of clearance in the shafts (input shaft, etc.), sealing compound fails to provide the desired sealing, loosening of clamp holdings, failure of properties of seals and gaskets and other effects.

Transmission Dyno Stand Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Dyno stands allow testing complete gearboxes in assembly checking their performance and understand if it is comparable to benchmark characteristics. It is the tool that is certainly needed to provide certified transmission quality. There are options that allow advanced testing of FWD, RWD, AWD automatic transmission vehicles, for both civil and heavy duty models. A dyno stand used to be an expensive option for big-scale car transmission rebuilders but more accessible quality options start to emerge on the international transmission service market.

Why is it important to use a transmission dyno test stand?

What are key components of a transmission dyno?

What is the difference between electric motor and combustion engine dynos?

Principle of operation | What types of load cells are there in the dynos?

History of transmission dynos on the industry market

Pressure gauges in transmission dynos

Importance of hardware with transmission dyno stands

Importance of software with transmission dyno stands

Major suppliers of automatic transmission dynos

The transmission of an essential part of a vehicle drivetrain system, transferring power to the wheels, doing gear switching, distributing load. Depending on the context, to a large degree term ‘transmission’ is synonymous to ‘gearbox’.

What is the utility of using transmission dyno test equipment?

In the transmission repair industry, testing of a complete automatic transmission unit is imperative for large remanufacturing companies dealing with large repair volumes, is quite desirable for medium-scale companies working widely on the national level and supplying to other countries, and is a dream for smaller transmission shops that always do test-on-the-car checks to verify the repair procedure. In addition, many educational institutions (like tech colleges) need dynos for proper students’ skill-learning process. Production companies use transmission dynos in their EOL tests (end-of-line testing).

“Dynamometer” consists of two words - dynamo (Greek for “power in motion”) and meter (also Greek for “measurement”). Very often, it is simply called as “dyno”. A dyno stand used to be a costly tool solely for big-scale transmission rebuild shops, nowadays, however, more accessible options of these tools are emerging on the international transmission service market.

One who is new to transmission repairs may actually wonder: ‘Why a transmission should be dyno tested?’ It is primarily about warranties and guarantees given by the provider of repair services. A dyno test ensures that a transmission is performing well and adequately under certain conditions of operation and this gives a huge grade of certainty that the transmission will last full life expectancy.

The dyno testing means that you mount a transmission in the dyno test rig and drive it through various paces. The idea of such testing is simulation of real-life operation conditions as if it were driven in the car on the road. At this, the gearbox is taken through a complete set of operations, with gear and speed switching, and in each gear operation is performed through the design speed range. Certainly, it is vital to capture output values, and these are monitored in the test process.

Reputable transmission remanufacturers set their goal to return the rebuilt product to original factory specifications. With dyno testing, the following key parameters are checked: torque, temperature, pressure. Also, operations efficiency is checked and sensor functionality test is performed. The tech operator is able to verify bolt torque and presence or absence of leaks in the system. To put it straight, the dyno test assures that your gearbox operates according to the factory specifications with due regard to design speed and range of gears.

You need to dyno test gearboxes when:You strive to provide top quality of your rebuilds.

You want to be sure of the longevity of warranties that you give.
You want to speed up your repair processes.
Your partners who contract you in large volumes need assurance of compliance with highest reman standards.
You value your shop’s reputation and you want to avoid unwanted returns damaging

Basically, without dyno testing you have difficulty proving that the gearbox will not fail in operation conditions. Although the guarantee might have a fault covered, it is your reputation that you need to protect and avoid frustration when a gearbox is returned back with faults.

What is more, health of the transmission means that no harm will be done to the drivetrain and no further damage to the engine. Another vital idea is that a high quality reman transmission can be better performing than a new factory one. This is important for transmission performance shops and racing car workshops.

What are key components of a transmission dyno?

It is important to understand key components of a dyno test rig as a transmission specialist may wonder how it functions.

Primarily, modern dynos are fully digital and allow for highly accurate easy-to-perform repeatable automotive transmission testing. The important factor here is software and hardware, which is realized in the controller system. These dynos simulating automotive load conditions are typically quite universal and adaptable to various modes of wheel drive and automatic transmission types (including CVT transmissions). In order to cover this universality the test rig is performed with due regard to capacity requirements, motor horsepower specs, number of load cells. Let us cover the components of the body of a transmission dyno.

High-output motor (nowadays it would be an electric motor)
Load unit (for dynamic loaded testing). At this, number of load cells is varied for various applications: 1 unit – for RWD (rear-wheel drive) vehicles, 2 units – for FWD (forward-wheel drive) vehicles, 3 units – for AWD (all-wheel drive) vehicles
Jib crane for transmission mounting and dismounting
Pumps with hoses to fill and drain transmission fluid
Pressure sensors
Oil tank and drip trays
Stall brake
Quick release hose fittings

Additionally:

Electric shuttle motors allowing positioning for different transmission configurations
Tooling kits for transmission positioning avoiding any potential harm to pumps or certain transmission components
Bushings for precise transmission alignment

What is the difference between electric motor and combustion engine dynos?

Modern dynos run on electric motors, they use electricity stored in batteries and power electromagnets driving axles.

Combustion engines run on gasoline, which explodes in an enclosed space – it is a well-known process happening in most of the cars driving on our roads, hence the name. In vehicles, this combustion moves pistons, which rotate engine’s crankshaft and all that controls rotation of the vehicle’s axle. This solution is pretty much obsolete and not used in up-to-date dynos for a number of reasons:

CE has many more parts and occupies more space (CE with ~2000 parts and EM with ~20 parts). Fewer parts also means easier serviceability and maintenance.
Disposable fuel with electric motors, while in a combustion engine, the disposable fuel is gasoline, which must be carefully stored, as there is a danger of ignition. What is more, fuel leftovers must be exhausted out of the after combustion.
Electric motor battery packs are expensive but gradually become more accessible.
With electric motors little energy is wasted, but with combustion engines quite a serious percentage of energy is lost along the way. Therefore, it’s the gas-powered vehicle that needs more energy.
It is more comfortable and convenient to service an electric motor in a transmission shop surrounding, if comparing to a combustion engine.

Overall, 75kw (or ~100 horse power) is enough to drive modern transmission dynos for light-duty and medium-duty application. At that, electric motors are very much preferred.

Principle of operation

It is important to distinguish transmission test stands from these two types of dyno stands: engine dynamometers and chassis dynamometers. With engine dynos, the engine is removed from the vehicle and installed on the stand by connecting directly to the flywheel. For this purpose, transmission specialists use special adapters and it is also necessary to connect the cooling system, as well as some other components - this procedure takes a lot of time. Engine developers and manufacturers mainly use these stands.

Chassis dynos allow for testing of the vehicle as it is driving on the road, fully assembled. These are rather popular among people doing racing cars or performance vehicles.

Transmission testing stands are suitable for both transmission manufacturers and transmission repair service shops. During testing of complete gearboxes their performance is compared against benchmark characteristics. Multiple readings are taken using corresponding sensors and transducers, their readings are converted to visually explicit and perceivable information. Obviously, transmission dynos vary in their design to cover FWD, RWD, AWD automatic transmission vehicles, support and fit civil light-duty and/or heavy-duty models. Precision alignment tooling and data acquisition & control systems play an important part in quality transmission testing.

What types of load cells are there in the dynos?

Dynamometers are classified by the method of creating a load. Nowadays, the accepted brake standard in a transmission dyno is eddy current brakes.

EC brake is an electrically controlled brake with air cooling. In it, load is created by inducing a magnetic field in a rotating disc. Heat produced by the rotating disc is dissipated in air. Moving parts are stopped by EC brakes with the help of drag force. These brakes are a great option for lower power applications and dynos up to 250 hp.

Water brake works on the transfer of water momentum creating load on the tested unit with the absorbed power heating water. Usually, these consist of a turbine / propeller, which is mounted in an enclosure with water. Water brake are for high power applications far over 250 hp. Largely, for engine dynos with thousands of hp.

Alternating current dynamometers are another option which is less frequent when compared against EC’s. These are used for engine dynos and the idea is in mimicking the load placed on the engine as it powers vehicle.

History of such equipment on the industry market

Transmission testing equipment has a particular history in the USA, the leader of car industry. The world’s largest manufacturer for this type of equipment – PowerTest – is located in Wisconsin. They started in 1976 and grew to acquire a large number of brands and companies from the industry. Nowadays, PowerTest owns such brands as AIDCO, Axiline, Hicklin – all of them shall be known to people who spent decades in the transmission industry.

Another well-known US manufacturer is MAE (Mustang Advanced Engineering) who were on the market since 1970’s as well. As of today, they provide a system for testing automatic passenger car and light truck inline and transverse transmissions as well as systems for medium- and heavy-duty applications.

There are some other companies located in the USA but they are far less active and less known to a global audience, as of today.

Although, dynamometers have been around since as far as the 18 ^th century, quality transmission dyno options are not as many as one might have thought.

In the 21^st century, USA are not sole prominent manufacturers and they need to compete with companies like RayTech from China or Hydra-Test from the UK for the global buying audience.

Pressure gauges in transmission dynos

In previous decades, the equipment output gauges were analog but nowadays there is obvious tendency for digitalization. With modern control systems, the process of running through gears and checking electronic solenoids is automated. One single system runs many different vehicle and transmission types.

If a transmission stops working because of a sensor, harness, connector or solenoid, it will be visually shown on the screen, explicitly as to identify this failure. Comprehensive data on each sensor can be compared against the benchmark result and thus it will be easy to determine whether that particular sensor is good or bad.

Multiple fluid pressure gauges enable thorough shift timing evaluation and adjustment. Controller box ordinarily comes for 8 pressure sensors with quick fit connectors. This can be expanded to 2x times (total 16 pressure sensors) if this happens to be required in the technological process. Readout in modern dynos is easy to adjust for any needs – especially if the software is appropriate for client-specific demands.

Importance of hardware with transmission dyno stands

Modern advanced dyno stands allow control and full testing of electronically shifted Mechatronic gearboxes and valve bodies. The importance of hardware for such dynos cannot be understated.

Modern dyno stands provide complete computerized control and with that extremely precise test procedures are easy to repeat. Some companies like Axiline concentrate on the US domestic market. However, the range of supported gearboxes is typically large: the dynos fit most USA home and non-national RWD, FWD, transverse, and Continuously-Variable Transmission gearboxes. These dyno stands check:

gearbox line pressure,
TC lockup and downshift,
shift point and response,
stall speed, and more.

At this, emulated load conditions for vehicles are applied and speed and load are measured with potentiometers. Transmission rebuilders will be able to confidently spot ATF and pressure leakages, check controls of the systems and hydraulics, and perform minor corrections with the gearbox still being mounted on the tester.

Reliability of hardware and flexibility of software are equally important for efficient use of transmission dynos.

Hardware is the brain of a transmission test stand. You do not have to be an IT-specialist to know to value enduring components that will serve to last for years and that will be protected from any electric malfunction.

In many cases, a physical body of the transmission dyno is still able to last for years, however, the hardware or the controller itself is very obsolete and cannot meet demands of those new development that have come by recently. When looking for such an advanced tool, it is also vital to look into this aspect of the equipment – how is it going to be supported after a couple of years of operation.

For instance, the most-professionally done Chinese dynos are looking really good, but the hardware part here is just a contribution and doesn’t bear any advantages. Axiline (at PowerTest) has quit updates for their controller system and just go with what had been on for many years now.

A good option to look into are companies that supply controller systems separately form the dyno testers. This means that they are concerned about all the aspects of the equipment: physical, hardware, software – and can deliver a lasting product. Hydra-Test’s HTC-S is adaptable for existing dynos from former years. If the machine has served years and is still functioning well, it can be easily refitted with a new controller box – enhancing the functions and data validation and processing.

For instance, among transmission dyno users from the USA and Europe there is often a situation when their current system is obsolete and shows the following deficiencies:

Difficult process of programming new units.
Inability to smoothly ramps solenoid current.
No support for newer developments that came into market after 2020.
Absence of reliable tech support from the manufacturer.
Current transmission controller being no longer in production.

A new controller generation tackles these issues quite successfully and relatively easy. If you happen to be negotiating with a particular company’s manager, ask all of those questions upfront. New controller systems ideally have to come in a modular format when it is possible to build up a controller from several modules facilitating the support and any future upgrades.

New units coming to the market can be controlled efficiently with adaptability and flexibility of software. Ask your supplier if it is possible to write your own test scripts, this feature may be hidden but is pivotal for efficient use of transmission dynos.

Interpolation feature allows for solenoid ramp up, and with ease. New developments like Mercedes 722.6 or latest Chrysler models (like 68RFE) are supported equally with older designs.

Technical support is pivotal here. You do not want to be stuck with a fault that your supplier cannot be resolved for you. Large transmission equipment companies or companies coming from non-European countries oftentimes have these issues.

As an important note, remember that mechatronics have a different testing method and a 3 ^rd party supplier of equipment cannot have OEM access codes. Their use is restricted and protected. Therefore, do not expect that your transmissions can be tested along with their mechatronics components. It is simply not the case.

Mechatronics are excluded from the testing circuit with universal transmission dynos. They are tested separately by individual OEM tools – like ZF Testman and the like for other OEM’s. Double- or triple-check it if your potential supplier promises to supply mechatronics testing with their equipment.

Importance of software with transmission dyno stands

The IT field is on the rise and its advancements have also concerned the pretty much conservative transmission repair industry. When considering a transmission dyno, check for the following factors:

Date of software release
Frequency of software updates
Ease of update installations
Presence of online tech support
Possibility of desk sharing sessions (for example, via TeamViewer)
Flexibility of operational algorithms and their adjustments to clients’ needs
Convenience of output data readout and printing out
Attractive and user-friendly design

In fact, the software factor oftentimes goes without notice but it plays an essential role in efficacy of the dyno system. Just imagine running your high tech tool on Windows XP when it is 2020’s. This discriminates the whole investment.

Major suppliers

Nowadays, it is easy to commerce internationally and the suppliers are not limited to their local markets. US companies supply to Europe and to Turkey, Chinese suppliers have clients in the Middle and Near East. European suppliers have clients all across the globe – from Mexico to New Zealand. A certain group of suppliers works chiefly for the post-USSR countries.

1. Power Test

Active since: 1970s

Location: Wisconsin, USA

Types of equipment supplied: transmission dyno test stands, engine dynos, chassis dynos, valve body test stands, torque converter repair equipment, and other (all via different brands – Axiline, AIDCO, TCRS)

About: on the market for over 40 years, Power-Test has been providing test equipment to both manufacturers and rebuilding facilities and distributors in various field of industry. These include mining, oil & gas, power generation, and particularly military applications, marine, and construction.

Product updates: not recently.

Power Test has been acquiring local USA companies under one hood and is the largest company producing these types of products in the world. At that, the most powerful products are by AIDCO as they are for military applications. Test stands for transmission shops come as contributing to overall Power-Test profile.

CHECK OUT PRODUCTS https://go4trans.com/superflow-dynamometers-and-fl...

2. RayTech (Guangzhou Ray Technology Solutions)

Active since: 2010s

Location: Guangzhou, China

Types of equipment supplied: transmission dyno test stands, valve body test stands, torque converter repair equipment, and transmission parts.

About: Some Chinese suppliers cannot be counted on, simply because of how they present their product. RayTech is different in these terms although their web presence is also a little unclear to a European or American potential buyer. They also take part in certain expos across the globe.

Product updates: new test plates for RayTech equipment.

Raytech is probably a most recognizable supplier of transmission equipment (along with a Chinese company TranSpeed). Despite having a good portfolio and attempts to position their products, some proper online presence could be improved. This supplier may be best to be contacted via Chinese local trading platform.

3. HYDRA-TEST (Cottingham Engineering LTD)

Active since: 1990s

Location: Kettering, United Kingdom (head office) / Minsk, Belarus (daughter production company)

Types of equipment supplied: transmission dyno test stands, valve body test stands, torque converter repair equipment, valve body repair tools.

About: at this day, Hydra-Test is the only prominent and reliable transmission repair equipment supplier from the United Kingdom. In 2019, the company opened a subsidiary production office to be more competitive in terms of product production cost and be able to deliver most reliable support quality. Valve Body testers by Hydra-Test are known for durability and full coverage of clients’ demands. Hydra-Torque equipment fabricated in the Belarusian division since 2017 has been supplied to various countries, including a heavy-duty application. The team is also open for custom-built solutions and delivers them in exact match to clients’ needs.

Product updates: Hydra-Dyno (launch of transmission dyno production), HTC-S (newest controller generation), 0AM valve body test tool.

ThisUK supplier is well-known for their attitude, constant update of available solutions. Opening a production site in Belarus is also an advancement. Some companies from post-Soviet territories can be barely counted on. However, if guided by European service standard, it is a great combination of affordable price and highest quality of transmission repair.

CHECK OUT PRODUCTS https://go4trans.com/hydra-torque-transmission-dyn...

4. Mustang AE

Active since: 1970s

Location: Ohio, USA

Types of equipment supplied: dyno test stands for a huge variety of applications (including transmission dynos), solenoid testers.

About: on the market for over 40 years this company has launched a series of equipment for various applications, including military sector, heavy-duty equipment, and more. The company aspires to deliver creative thinking to drive continued success. They are one of the leaders in delivering sophisticated dynamometer technologies and advanced engineering capabilities.

Product updates: not recently.

Mustang AE’s growth has been hindered recently but it is a supplier worth referring to at least for comparison. A company with such a serious portfolio that includes emission measurement system fabrication, own design services bureau and more is certain to work on transmission repair clients’ requirements in a diligent way.

5. Extra:

We tried to contact alternative Chinese and USA suppliers to provide more info for consideration here but were treated with silence or an awkward invitation to come to China to see the machine and learn about pricing.

How to repair this transmission (Videos)

RockAuto Auto Parts transmissio being dyno tested

G-TEC: transmission dyno

Powerglide On The Dyno

Transmission dyno upgrade with Hydra-Test HTC-S controller

Transmission dyno at Certified Transmissions

G-TEC: DYNO Transmission Tester for "light" vehicles

How your Transmission was Dyno Tested

Supeflow. Axiline transmission dynamomenter

Instruction manuals and useful links

Link type	Source	Description
pdf	http://promand.com.au	AXILINE 66K TRANSMISSION DYNAMOMETER
pdf	Superflow	Axiline 97000 dyno brochure
pdf	Powertest	Powertest transmission dynos. Product brochure
web	MAE	Mustang MAE transmission dynos
web	Gearstar	Was your traansmission dyno tested

Torque Converter Balancing Unit Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Balancing is used after all components have been replaced and subsequent welding is done. The process of balancing allows transmission service people to find out if there is a bad or uneven weld on the circumference of a Torque Converter. If it is identified, the operator can easily weld on a small amount of material or remove it. Performance transmission and racing transmission specialists pay special attention to Torque Converter balancing.

When you turn the ignition key the Torque Converter starts to rotate together with the engine. Torque Converter of about 250mm in diameter and of about 10 kg in weight imbalance in its RPM can cause such a serious vibration that the entire vehicle will be affected, including fastening elements of the engine and the automatic transmission.

Balancing machine for torque converters allows us to check imbalance of this element with guaranteed accuracy. Precision system implemented in these machines allow transmission repair experts to pinpoint exact place of excessive or insufficient weight.

Vacuum Test Unit Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The Vacuum Test Unit is used to test the vacuum integrity of all Valve Body hoses and valves. This method of Valve Body testing is considered to be quite a traditional testing solution for transmission shops - it is a money-saver which does a straightforward job. At the same time it doesn’t provide the many advantages of the modern sophisticated transmission service tools. Vacuum tester is often used jointly with a Valve Body test equipment for remarkable results.

The vacuum test allows to evaluate the condition and wear of the valve (plunger) in the body of the hydraulic unit. A worn valve or a hole in the hydraulic unit may result in improper operation, reduced performance or malfunction of the automatic transmission. In most cases, it is possible to assess the wear of the hydraulic unit of the automatic transmission without the vacuum test. However, if you have repaired hydraulic unit with the help of special reamers and valves produced by such manufacturers as Sonnax, a vacuum tester is a must because the vacuum test allows you to quickly and easily test for leaks in the channels of the hydraulic unit.

Solenoid Tester Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Many Valve Body problems are due to solenoid issues. Typically, a Solenoid tester is similar to a Valve Body testing unit - it is offered by the same manufacturing companies with similar software and hardware changed to do job only on Solenoids. It comes as an efficient solution to smaller-scale transmission repair businesses looking for a more affordable solution to improve their Valve Body rebuilding quality and general automatic transmission rebuild standards as well.

Solenoid testing machines are used for checking the state of solenoids produced by different manufacturers of automatic transmissions. Separate solenoid test blocks make it possible to run tests for the majority of most popular makes on the actual international market. Modern Solenoid Test machines now typically come as a universal model and allow to cover any transmission specialists’ preferences in transmission rebuilding operations.

Modern Solenoid Test tools allow possibility to run tests at maximally high required temperature and solenoids are tested as they function with the valve body, as originally designed. The automatic transmission solenoid is an electromechanical regulator in the gearbox, in response to the computer impulse it opens or closes the channel in the hydraulic unit to control flows of hydraulic fluid. Solenoids control the hydraulic switching of operation modes in modern automatic transmissions, CVT and DSG. The solenoid is inserted in the channel of the hydraulic unit and is fixed by bolts (or a pressure plate) and at the other end through the plug of the wiring harness it is connected to the electronic control unit of the automatic transmission.

How to repair this transmission (Videos)

RayTech Tester for Transmission Solenoid

Hydra-Test Solenoid test machine guide

Transmission Solenoid Testing (Ohms Law)

Automatic Transmission Basic Solenoid Testing

How to test automatic transmission solenoid status: OK or Bad ?

Hydra-Test HT-SOL 25 - Intro

How to test a Transmission Solenoid

Instruction manuals and useful links

Link type	Source	Description
0	Gears Magazine	Transmission Solenoid Test Methods
0	Gears Magazine	Understanding GM 6T40 Solenoids
0	Gears Magazine	Subaru Lineartronic CVT Lock-Up Solenoids
0	Gears Magazine	Ford Solenoid Strategy Numbers: Is It Necessary to Program?

Valve Body Tester Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In the automatic transmission, the valve body serves as the hydraulic control center responsible for gear shifting and torque converter clutch application. Inside a valve body, one will see a maze of channels, different sets of valves, and a variety of solenoids. These all work together controlled by the transmission control unit or module (TCU or TCM) to direct hydraulic fluid through these passages to the valves activating the required clutch pack or servo to apply or release these elements causing gear changes and torque converter clutch application. Modulation of the components is what provides smooth gear changes over the range of throttle application or driving conditions.

Why is valve body testing important and necessary?

Valve body testing covers a significant range of tasks. Among these, one may distinguish 5 principal ones as below:

Speed up the process of repair of a worn valve body,
Be able to pin-point a source of malfunction within a valve body,
Provide confidence in valve body repair for extended warranties,
Be compliant with stringent quality requirements,
Provide end-of-line testing for a new valve body as a factory product and performance valve body testing.

The only other viable option to test a valve body is to test-in the vehicle, which involves a large amount of labor and technician time especially on newer vehicles where installation and removal of the valve body may require other vehicle components to be removed to gain clearance. Simple remove and reinstallation of a valve body inside a car can take up to 4 hours to complete. If a shop is specializing in transmissions and valve bodies and repair volume is low, this might be an option that works for them, but most shops are competing on price and so the required technician time make s this an expensive option. The real issue with this method is when there is a fault or malfunction that is not obvious and the technician has to perform the install, test, remove, and repair procedure multiple times to try and identify the problem or worn circuit in the valve body. If a shop has any significant volume of transmissions to repair, the technician and owner simply do not have the spare time to do this and needs to avoid time-consuming troubleshooting road tests.

Subsequently, conventional scan tools and pressure gauges do not always suffice to determine what exactly is causing the trouble within your valve body, especially if it has significant mileage. An inexpensive vacuum tester is certainly a must-have for a quick bench test upon tear down. It serves as a cornerstone every time one starts valve body inspection and repair. A vacuum test can identify a worn valve or questionable circuit, but it may be difficult to determine the degree to which a valve, or a bore, is worn and it may not identify the wear as clearly as needed. A valve body tester emulates road conditions and actual hydraulic operation of the valve body in all gear ranges as well as near the normal operating temperature of the valve body. The valve body can be tested at a variety of pressures with temperature control and strict control of solenoid amperage to simulate the hydraulic modulation as gear shifts occur. The performance of the unit under test can then be compared against benchmark data in a graphical or tabular format. This allows a technician to identify faults or questionable data that are not able to be seen in the vehicle. The modern valve body test is a complex and eloquent tool that gives the technician the ability to identify the exact source of trouble, leaving little room for doubt and giving confidence that the repair has been performed correctly.

The ability to provide extended warranties and to keep warranty claims as low as possible have a direct effect on the reputation of a shop. In order to be confident in the repairs to offer these types of warranties it is important that the unit is thoroughly tested using consistent test practices. A shop with high warranty claims, even if addressed and the issues rectified, can suffer from unhappy end customers and this can have a direct effect on the reputation of the shop. Therefore, if one is concerned about delivering the transmission shop’s valve body repair guarantee and protecting the shop’s reputation, quality valve body test equipment is crucial.

Another important factor is compliance with certain requirements for a repaired product. This comes into play if a shop or remanufacturer enters in a contract with larger companies providing multiple repaired or rebuilt units. This is common in fleet accounts where the removal and installation of the transmission is not done by the shop remanufacturing the unit. When doing this kind of work there may be a requirement that repaired or remanufactured units meet a certain quality standard (confirmed by thorough testing).

One more application for advanced valve body testing is end-of-line testing. This is typically larger remanufacturing companies or even OEM that need to make sure that the unit just built is performing as per the specification and there has been no fault during the production process. This can also include performance shops that build valve bodies for racing or for heavy duty / towing applications. The volume may be lower, but the use of a valve body tester is critical in these operations as well.

History and principle of operation of a transmission valve body tester

Valve body test equipment started to become common among transmission repair shops in the early 1990s as valve bodies transitioned from hydraulic cast iron three speed units, to aluminum electronically controlled four speed units. During this pre-digital era the equipment was fully analog with multiple pressure gauges to show readings and even lights with pressure switches to show if there was a minimum amount of pressure in a circuit.Valve body test equipment has started to gain among transmission repair shops of various scales back in 1990s and during that pre-digital era the equipment was, obviously, fully analogous with multiple readings shown on the external gauges.

At that point, the principal components of a valve body tester were the machine itself (mainly a pump and pressure regulation system, the corresponding test plates connecting the test unit to the machine and gauges, and a basic shift controller that would fire the solenoids on or off to achieve each gear). An operator would need to watch the gauges upon a gearshift and make a determination on the quality of the unit based on experience. Nowadays, the data acquisition and processing controller integrated into the testing process plays the key role in modern testing. At that point, the pivotal components of a valve body tester were the machine itself and the corresponding test plates connecting the test unit with the tested element. Nowadays, the data acquisition and processing controller integrated into the testing process plays another vital role. Here we may have a close look at all the three key elements that were specified.

If we break down the key elements for modern valve body test machines, we can see there are three key areas:

1) The principal components of a modern Valve Body testing machine:

The hydraulic pump and motor,
Suction and high-pressure filters,
Input and output pressure transducers,
Heating elements and temperature controllers,
Proportional and gate valves,
Oil tank (to be filled with automatic transmission fluid),
Integrated personal computer or a portable laptop.

Based on this list, the idea is that the system feeds ATF into a valve body under varying pressure and temperature conditions. These would vary to emulate real-life driving conditions.

2) Valve Body and Solenoid test plates and adapters

These adapters emulate the case connection for a valve body or the bore in a valve body for a solenoid and allow the unit to be connected to the test machine. Connection test plates may have orifices for compatibility with certain valve bodies and plumbing to closely emulate how fluid is fed in the vehicle. Connection hoses and cables differ depending on the model. Typically, plates and cables are model specific and it is one test plate and one cable for a certain model of valve body.

3) The control system to drive solenoids and data acquisition for recording and presenting test data.

With the advent of modern valve bodies coupled with mechatronics units, the task of powering and controlling solenoids is not getting easier or less critical. As there is currently no universal tool to test mechatronics components (link: https://go4trans.com/technical-valve-body-articles/advanced-hydraulics-testing-for-valve-bodies-why-there-is-still-no-universal-solution-for-mechatronics-assemblies/), valve body testers are designed to universally test the hydraulic parts of these valve bodies. With modern units, PWM solenoids require a special approach that is vastly different from ON/OFF solenoid testing and for this purpose more complex controller systems and software are required.

Data acquisition is much more crucial with testing of modern valve bodies. The ability to capture data at 500Hz-1000Hz is necessary to comply with up-to-date valve body testing standards. With 500-1000 reading per second, one can be sure that no data will be missing, and the valve body or solenoid faults will be easy to identify.

The acquired valve body data is then compared against benchmark data previously store in the system. This is done via graphical overlay of the tested performance data. With a visual graphical display pin pointing faults can be done quickly and easily.

What types of valve bodies can be tested?

Modern valve body testing systems are built to be universal and are suitable for transmission repair shops across the globe. The testing process itself does not change from a valve body to valve body. All units are tested hydraulically, and solenoids are checked electrically. The necessary part is that the manufacturer has to be able to provide a valve body test plate suitable for a new / particular valve body.

There are a few aspects of testing for various valve bodies worth touching on separately:

1) Latest model Valve Bodies with mechatronics, or TEHCM testing (for a thorough review, read the article: https://go4trans.com/technical-valve-body-articles/a-good-closer-look-into-mechatronics-units-testing/)

Generally, the mechatronic part is omitted from the testing circuit. There are 2 key reasons for this. Firstly, there is no universal tool that can test all varieties of TEHCM applications. Secondly, a transmission specialist really wants to test all parts separately – to be able to identify the valve body fault most clearly without questioning if it is a valve body or a TECHM programming/fault.

Power Test’s Axiline has a solution to test just a few types of TEHCM applications with their WinDyn Test Cube system. There is number of limitations with this system as the system can only test:

-6HP19, 6HP21, and 6HP26 mechatronics by ZF but not all types of these models (with exclusions by years),

- some GM (General Motors) models: 6L45, 6L50, 6L80, 6L90, 6T40, 6T45, 6T70;

- DQ200 (0AM) and DQ250 (02E) among DSG’s.

Another concern is whether this solution is worth the investment as the Test Cube by Axiline is nearly as costly as the valve body testing machine itself. The standard solution is to use corresponding TEHCM tools by OEM’s – like ZF Testman for ZF.

Other manufacturers of valve body testing equipment have omitted the mechatronic part from their test cycle.

2) Solutions for Valve Bodies popular in all countries across the globe

Axiline specializes in the USA market and concentrates on the models that drive on the North American roads: GM, FORD, Chrysler, and Allison. For example, the Axiline solution line for GM is widely used globally on popular models such as 4T65-E, 5L40E, and 6T40/45. Some of the supported models are most common in the US becoming quite old – for example, 200C, 400. Concentration on the USA models is not surprising as the USA car market is the largest world market – however, this leaves transmission repair specialists from other countries of the world not covered.

Raytech or Transpeed, which are China-based, offer solutions based upon models popular on the Chinese roads - although they trade globally and strive to provide solutions across the globe.

Hydra-Test has opted for universality and the solution that covers all of most popular models globally and locally: German valve bodies by ZF and VW; American valve body models by Ford, GM, and Chrysler; Asian transmission valve body models by Hyundai, Kia, Toyota, Nissan, and more.

Kinergo’s Valve Body test machine, an emerging solution from the advanced post-Soviet industrial region, is covering what is in demand and the team provides solutions inspired by other manufacturers.

3) Continually adding new testing adapters and solutions

As a repair technician needing to stay current with the ever changing automatic transmission repair market one would want to invest in a tool that will be on pace with the trends, model updates, and new models of the industry. Therefore, it is vital that the likes of the 9HP by ZF, AC-60E by Toyota, 8 speeds by GM, the 10L by Allison, or latest CVT’s like JF016 are being added to the range of solutions by your supplier of automatic transmission repair equipment.

4) Custom-built solutions

If you are developing your own valve bodies or if you are producing performance valve bodies, it is necessary that the manufacturer of your equipment knows to handle solutions that are demanded by your company. A need for personalized valve body testing can be met with reluctance to take it on or a high cheque. However, for some manufacturers this is a good cause for faster introduction of newly-launched valve body models to their product range. For instance, this is how Hydra-Test took on heavy duty solutions: although the company specializes in the models for light-duty civil vehicles, they have introduced VOLVO CE (Construction Equipment) PT2116-PT2509 and PT1860-PT1861 as there was a demand for this.

How do valve body testers check individual solenoids?

Generally, valve body testing equipment allows for solid verification of solenoid operation. The technician can see how solenoids installed in a valve body perform in the valve body assembly. Here we shall focus on how valve body testers can be used with solenoids separately from the valve body.

If a transmission repair specialist is just beginning to repair and remanufacture their own valve bodies, they may opt for a solenoid tester and valve vacuum tester combination. A vacuum tester is conventional inexpensive tools – Sonnax vacuum tester is the option of preference.

There are several methods of solenoid testing but a most thorough check is with implementation of advanced solenoid testing equipment (check the solenoid testing equipment section). The question comes up on if a transmission technician has to have separate solenoid tester and valve body testing machines? The answer really depends upon the volume or work a shop has. If you can split the time needed to test solenoid and valve bodies on one machine then there are solutions to test both in a valve body tester. However, if the volume becomes such that testing solenoids holds up being able to test valve bodies, then the shop is really in a position of needing two separate machines.

The option of testing solenoids with the valve body testing equipment makes sense when you have lower volumes of work. This feature is easy to add as by default the hardware, software and the controller of a valve body testers is more advanced than that of solenoid testers. They only step needed is addition of solenoid testing blocks with a valve body tester so inquire if your potential supplier has the ability to easily add this feature to the valve body test machine.

Here is an example of the UK’s Hydra-Test add on adapter package for solenoid testing on their VBT Deluxe. A solenoid adapter plate is placed in place of a typical valve body pate and their line of solenoid test blocks fit exactly as they do in the solenoid machine. The solenoids can now be checked hydraulically and electronically with all the same quality of data capture and processing as the valve body testing.

Importance of hardware with transmission valve body test stands

Hardware plays crucial role in reliability of the testing equipment and certainly contributes to having the equipment up to actual standards as time advances. The are many internal components that serve to capture and process transmission valve body operational data. These are the pressure transducers, power supply, transducer distribution board, cabling kit and leads, temperature controller, and so on.

The hardware serves as the control center of a valve body test system and it is the key of valve body performance data processing by using pulse width modulated solenoid outputs, analog inputs, discrete inputs, frequency inputs, analog outputs, temperature sensors – as key data acquisition components.

Most often, suppliers of testing equipment develop and apply their own hardware unless there is a need for some specific solution. An example of past cooperation between companies in the industry was Mustang Dynamometer and PCS (Powertrain Control Solutions). PCS controllers were private labeled for Mustang as a means to support a large variety of transmissions in the mid-2000’s for their tests at the time. However, cooperation between a few parties in not a strategy to last long enough and the best approach is using own solutions.

Hydra-Test has brought the controller development in house with their initial release of their HTC-K controller and more recently the HTC-S controller. This is the latest controller capable of valve body and transmission testing. The hardware components here are built to last with extra protection and convenient modular system, so the system can grow as a customer needs more capability and/or as new units are added and need to be tested.

How to repair this transmission (Videos)

Answermatic Valve Body Test machine

Kinergo Valve Body Testing machine

Hydra-Test Valve Body test machine guide

Hydra-Test Valve Body test machine overview

Hydra-Test 0AM (DQ200) valve body testing on a bench

ZF 6HP19 - valve body testing on Chinese machine

Valve body testing explained

A6MF valve body testing on Chinese tester

Vacuum testing with Sonnax tools

ATS Diesel Valve Body testing on a bench

Instruction manuals and useful links

Link type	Source	Description
web		Buy Hydra-Test Valve Body tester

V4A11 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The family of automatic transmissions V4A11 - V4A12 for 4WD (RWD- R4A11) drive of Mitsubishi Pajero Mini was designed by the AT (automatic transmission) department of Mitsubishi in 2000 simultaneously with FWD versions F4A11-F4A12. The difference between V4A11 and V4A12 is in slightly higher transmitted torque, but both versions use the same engine (0.7 liters). The 1-liter engine can be used only for F4A12 or R4A12 (AWD- V4A12). The V4A11 \А12 unit is mainly installed on AWD versions of Pajero Mini for a Japanese market. These transmissions were aggregated with a minimum 4-cylinder engine (0.7 liters) The design of all sub-modifications is quite similar, equally reliable, and this transmission goes so long that the cost of the machine at the time the overhaul of the machine becomes comparable to the cost of the bulkhead automatic transmission. The gearboxes were adapted for different engines and different underfoot spaces of the Mitsubishi mini-cars from (eK WAGON to Pajero Mini).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD/AWD		3,5	2	SP III

Technical issues and repair guidelines

The repair of these transmissions mainly consists of replacement of the filter and change of the transmission fluid.In most cases, the reassembly of the transmission, cleaning of the valve body and replacement of solenoids are performed by car owners. In many cases, the replacement of this automatic transmission with the used one turns out to be less expensive than its repair.

AS69RC Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

AS69RC is a 6-speed A/T produced by Aisin and initially intended for Ram 3500 HD. This gearbox took place of AS68RC in chassis cab modifications for 2013. It transmits the drive torque equal up to 1150 Nm. In terms of design this gearbox resembles AS68RC. AS69RC is large-sized and more reliable than AS68RC and 68RFE. AS69RC has 3 planetary gear sets, 1 overrun clutch, and electronically-controllable gear switching and the converter clutch.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD/AWD	1150	13	6,8	Mopar ASRC

Technical issues and repair guidelines

Specialists assume that the following service procedures are required for this transmission: change ATF every 30 thousand miles or 2 years, replace gearbox filter every 60 thousand miles or every 4 years. Starting from 2014 the modification AS66RC appeared to replace AS69RC in Dodge Ram trucks.

How to repair this transmission (Videos)

AS69RC Teardown Part

4N71B Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

4N71B 4-speed automatic transmission 4N71B was produced in 1984 for rear wheel drive Nissan 300ZX.This transmission is a successor of very famous 3-speed modification 3N71B. Since 1989 this transmission was modified for Mazda 929 under the name N4A-EL. In 2000 4N71B was used as a basis for updated JR401E, which is used with 3-liter engines V6.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	280	7		AT-Matic J

Technical issues and repair guidelines

This transmission appears in repair services very rarely. Due to its simple design specialists usually just need to replace worn-out spare parts and friction clutches to bring this transmission back to life.

How to repair this transmission (Videos)

Valve Body Shift Kit Installation

Instruction manuals and useful links

Link type	Source	Description
pdf	waghornswood.net.nz	Repair manual E4N71B
pdf	shinseiauto.com	Scheme 4N71B

BW8/12 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Flashomatic automatic gearbox was also named as BW8 (1956-66)/BW12 (1956-71). This gearbox had been actively installed on different models of Packard, Rambler, Studebaker during 1956-71.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		9,8	4,2	ATF Type F

This transmission is considered to be quite durable due to its iron case. The BW-12 was installed on some Ford vehicles in 1973-74.It is a hydraulically controlled RWD gearbox. This gearbox resembles Ford-O-Matic manufactured in 3 different case sizes used from 1951 until 1968) and FMX gearbox (released in 1968), but few of the parts are interchangeable.

THM425 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The THM425 (and later 325) is a 3-speed automatic gearbox designed and released by GM. The structure of the THM425 is based on the THM400; most spare parts in these gearboxes are directly interchangeable and some others can be adjusted with the help of slight modifications. The THM425 was designed for Oldsmobile Toronado and Cadillac Eldorado.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		12,3	6	Dexron II

More lightweight gearbox THM325 took the place of the THM425 in both car ranges in late 1978. Since 1979 and later longitudinal engine FWD cars have been equipped with the THM325. The THM325 was upgraded to THM325-4L with an overdrive added in 1982, but all cars with this gearbox switched to more-common transverse engine mounting in 1986.

How to repair this transmission (Videos)

TH-400 rebuild part 1

TH425 Governor Gear Removal

TH400 Rebuild: Governor

THM250 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic gearbox THM250 is based on the THM350. This gearbox was released in 1974 and was applied in Chevrolet cars. The THM250 was developed and designed by GM as a part of Turbo Hydra-Matic family of automatic gearboxes. When taking into consideration the internal structure of the gearbox, the THM250 is very similar to THM350, apart from the intermediate clutch package with a band adjuster.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		9,5	5,6	Dexron II

Generally, the THM250 was attached to small displacement engines. In 1976 this gearbox was taken out of production and was replaced by the light-duty THM200 transmission. However, the THM250 reemerged in 1979 as the THM250-C as a result of numerous issues withTHM200/200C. The 250C version had a reduced weight thanks to the use of a central gear shell applied the THM350, but with three holes to decrease flywheel mass and the low/reverse piston with eight notches.

Instruction manuals and useful links

Link type	Source	Description
pdf	oldcarmanualproject.com	Repair manual THM250

VT1-27 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

CVT VT1-27T Mini (or general name for this family - VT1F) found application on Mini BMW. In addition to Mini, this CVT was offered to Volvo, Land Rover, Hyundai, but this transmission rarely comes to repair services and its hard to find spare parts for repair of this CVT. The following modification CVT VT2 was a budget-friendly solution. This CVT had been offered to many automakers from 2009 to 2013.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	150	7,6	4,3	Esso EZL799

Technical issues and repair guidelines

This CVT has a typical design (with a solid reserve on transmission components) with a push belt and does not require repair for many years, except replacement of ATF and filter, and later – replacement of Bosh belt. This CVT was developed specially for BMW mini.

Settings of the VT1 control unit are adjusted for preserving expensive cones at low speeds, when the belt and surfaces of cones operate closely to the limit. Cones have wear-resistant cover of operating surfaces with the use of space technologies can not be rebuilt and not supplied to the repair market. CVTs of this generation are very sensitive to the level of ATF, therefore the check of this parameter is very technology-savvy.

Rare overhauls with reassembly of spare parts, wear-out of which leads to pressure losses on friction elements and as a consequence their (frictions) wear-out require the repair kit of gaskets and seals. While maintaining these CVTs experienced specialists replace the filter and change ATF as often as possible to avoid time consuming search operations for spare parts. Simultaneously with change of fluid and filter replacement, it is recommended to check the belt for wear-out of the protector. If there are any suspicions about wear-out, it is better to replace the belt. Even slightly wornout belt increases the risk of slipping (metal-on-metal) in situations with usual "non-sporting" acceleration in order to outrun the truck ahead. Generally, this CVT is quite comfortable and “invincible” under the condition of proper care. It is one of the top CVTs on the market.

How to repair this transmission (Videos)

Replacing Belt part 1

Belt replacement pt2

Mini Cooper CVT overview

ZF VT1 CVT Transmission Stepper Motor

Rover - Service Insight - VT-1 Automatic Transmission

Mini CVT transmission teardown

Mini CVT teardown test clip

Mini Cooper cvt adaptation

722.8 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 722.8 transmission (CVT) has been produced since 2005 and mainly used on Mercedes А170. It is also installed on other cars of А series with engine capacity from 1.5 to 2.0 liters.

The design of this CVT is based on model patent CVT with the "push" belt produced by Bosch-Fondorn and the most expensive spare part – the belt itself. This CVT is the analog and competitor of a Japanese CVT JF011E.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	300	7	6	236.20

Technical issues and repair guidelines

Overhauls of old cars with this transmission usually require the kit of spare parts (gaskets and seals from Autoline) and the kit of friction components. Friction components are replaced quite often in the process of the transmission reassembly, because the 722.8 unit is removed together with the engine, and easily wornout frictions already have a negative impact on the clutch. Driving with worn rings and seals lead to oil starvation and premature burning of quite durable friction components.

The fluid in 722.8 should be changed timely together with filter. The fluid and its purity are critical for cones and belts of this CVT, therefore for old 722.8 units, it is recommended to add the fluid at every opportunity and check its level with a service gauge.

The electrical part always causes a lot of problems in Mercedes transmissions. The board was made by the partnering company of Mercedes and after the warranty period you can face such problems as contaminated fluid (metal dust) and overheating. Steel dust magnetized on sensors lead to their failure.The belt is another vulnerable place in this advanced unit. Mercedes used the belt with additional resource on durability and reliability for its CVT.

Shaft bearings are the first among hard parts to get out of order (like with Jatco CVTs) because of lateral dynamic loads. The end of shaft-cones service life means the end for the CVT unit itself. The lifespan of bearings is highly dependent on the fluid cleanness, and most importantly - on its operating temperature.

How to repair this transmission (Videos)

Gearbox control unit sensor

Instruction manuals and useful links

Link type	Source	Description
web	actronics.eu	Mercedes-Benz Temic VGS (722.8)
pdf	autogear.fi	Scheme 722.8

U150E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic gearbox U250E is installed on all FWD and AWD vehicles produced by Toyota and Lexus with engine capacity from 2.5 up to 3.5 liters.

The whole range of U150 is more comfortable and economically viable (and high priced) alternative to "invincible" 4-speeds U140-U240. The 6-speed automatic gearbox U660 was produced in 2007 for Toyota Camry and Lexus car drivers who are more demanding of gear shifting process. The U150, 151 – can transmit a bit higher torque at low speeds than U250E. The U151F unit is intended for 6-cylinder full-wheel drive vehicles- RAV4, Highlander, Sienna.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	FWD/AWD		9	4	Toyota Type T-IV

Technical issues and repair guidelines

Major repairs of U150-250 units almost always starts with the torque converter repair and spare parts replacement ( lockup).The set of pistons is also included in the typical list of spare parts for repair of this transmission. The pairs of firctions (steel disks in the Overdrive drum) is the first component to get burned in these units. The second spare part to be considered is burnt Direct clutch (happens if the vehicle continuously operates with burnt Overdrive frictions).

The kit of friction components is ordered as frequently as the Overhaul kit especially when repair specialists have to deal with gearboxes with burnt ATF. Early wear of the Overdrive friction clutch is linked to the design of the rear cover, which plays the backup role for this clutch cover (drum). The other common issue for majority of these automated gearboxes is related to problems with pump seals and axles. The pump bushing is usually ordered together with abovementioned spare components. The main symptom of the problem is the ATF leakage through the pump seal. The main cause of this problem is an aggressive driving style and a long-term driving with burnt torque converter clutch.

Electrics in U250-150

Problems with electrical parts in U250 and U151 gearboxes are often triggered by issues with the valve body.The valve body U250 (2002-2004) frequently could not maintain set parameters, old (massive) solenoids couldn’t cope with tasks, therefore the valve body wears rapidly. In 2005, the valve body was updated after replacement of solenoids (the valve body itself was left unchanged). Solenoids for valve bodies of U250 and U151 units ranges for different cars and selected according to VIN-code of the car.

Peculiarities of early repairs of U250 and U151 units are related to the fact that the “electric clutch” was widely used in 2000-th and engineers refused from the "full-proof" comcept and did not limit capacity of the driver related to the aggressive driving style, that may lead to burning of friction components and other elements.

How to repair this transmission (Videos)

U151 Teardown

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual ECT U150E
pdf	www.at-manuals.com	Repair manual U150E
pdf	www.at-manuals.com	Scheme U150E
web	www.at-manuals.com	Solenoid identification U150E
pdf	Sonnax	Valve Body Layout U151E/F, U250E
pdf	Sonnax	Vacuum test valvebody U151E/F, U250E

B7TA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic 4-speed transmission B7TA was designed by Honda specialists in 1996. It is intended for front-wheel drive Honda and Acura vehicles.

This modification of automatic transmissions can be installed on 6-cylinder engines with the capacity not higher than 3.5 liters. In the process of operation this transmission made a good impression. Due to its simple design, this transmission is distinguished by its reliability and durability. The maintenance service for this transmission is not complicated.

HONDA ODYSSEY 2.3L; V6 3.5L; Honda B7TA

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		7,1	2,9	Honda Z-1

Technical issues and repair guidelines

After running 50 thousand kilometers it is required to change the oil with a filtering element. The car owner can perform this procedure by himself even with a limited experience in this field. B7TA has no planetary gears that allowed engineers to simplify the design of this transmission. It had a positive impact on the level of durability and reliability of this automatic transmission. It is not unusual, when well-timed maintenance and proper usage helps this transmission to cover 400 thousand kilometers without major repairs. Transmission specialists recommend warming up of the oil in this transmission in winter. It can be done the following way: shift the selector lever to the Drive position and hold the brake pedal depressed for about 30 seconds. This measure will help to warm up the transmission oil and prolong the trouble-free operation of the transmission. It should be also kept in mind that immediate accelerations after the start of the movement and gear-shifting in the manual mode may be harmful for the transmission.

The list of common problems with B7TA includes issues with rubber gaskets which lose their elasticity after running 100-150 thousand kilometers that leads to oil leakages. In this case the repair procedure lies in replacement of these gaskets.

How to repair this transmission (Videos)

B7TA Transmission - Honda Odyssey

Instruction manuals and useful links

Link type	Source	Description
pdf	drive.google.com	B7TA Manual

AB60F Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission AB60F (-Е – for rear drive) or AS68RC for Dodge RAM of the class extra heavy duty, Aisin name TB-68LS. This transmission was produced by Aisin Co since October of 2007 and paired with the engine V8 (5.7 liters) for 4WD SUVs such as Land Cruiser, Tundra, Sequoia, Lexus LX570.

This reliable 6-speed transmission with "invincible" design tested on rear-driven predecessors А760-960 and on 8-speed АА80Е released the year before (2006). The main competitive product of this transmission is ZF6HP32.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD/AWD	680	11,8	4,6	Toyota WS

Technical issues and repair guidelines

Electrical components in this transmission is extremely sensitive to the transmission fluid status. The oil change requires specific knowledge and experience.

During the overhaul the following parts are ordered for reassembly:the kit of gaskets and seals as well as kit of frictions.Friction components in this transmission are not complex and serve reliably till the end of the transmission resource. Frictions are usually changed as a result of operation with worn-out rings, bushings and sealing. First of all the, clutch drum Forward (С1 gears 1-2-3-4) gets burnt. All overhauls of the AB60F unit still involve the torque converter repair with replacement of the lockup clutch, replacement of burnt clutch, replacement of the filter and full spare parts kit: seals and gaskets made of rubber and paper.

The valve body design is similar to the valve body of the А960Е transmission and it should be expected that typical problems with electrical components may be the same (after the mileage higher than 200 thousand kilometers without timely change of the fluid and filter replacement) wear-out of channels of linear pressure solenoids. Aisin 6-speed transmissions also have the mode of regulated torque converter lockup slippery, but in contrast to 6НР26-32, here the lock device turns on much later (starting from the 3-rd gear) and have reduced impact on the friction.

Almost all solenoids (in comparison with the valve body in А960) functionally remained unchanged, except for linear solenoids SLU, SLT, SL2 in some modifications. Dirt in ATF damages the valve body and solenoids, therefore cleaning of these components is usually planned as the first stage of the transmission maintenance. During the first years after the transmission release automakers usually modify valve bodies, replace solenoids and change settings of ECM program. Therefore, it is recommended to monitor software changes, which may solve some problems in shifting.Mud accumulation in the valve body and solenoids as well as wear-out of rings lead to lower pressure in the Forward drum that results in premature burning of frictions with steel disks (Forward-C1) and corresponding Forward pistons.

How to repair this transmission (Videos)

AB60 Toyota Tundra Valve Body Removal and Installation

Toyota AB60E/F Power flow

AB60 Valve Body Removal and Installation

AB60F, Code P0983

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme
web	www.at-manuals.com	Scheme AB60E
web	www.at-manuals.com	Solenoid application chart
web	www.at-manuals.com	Stall test
pdf	Sonnax	Valve Body AB60E
pdf	drive.google.com	AS68RC manual

Allison 2000 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The Allison 2000 series includes modifications 2100, 2200 and 2300. This type of transmission was designed for light commercial vehicles operating in sectors of transportation and public transport. These transmissions are equipped with a turbine-driven power take-off mechanism with the N-locking option, and with a parking brake. Transmissions of 2000 series may have up to 6 gears, including overdrive, and be equipped with an advanced electronic control system of the 5-th generation, which provides more efficient operation and more diagnostic capabilities. These transmissions are reliable and highly efficient and can transmit power equal up to 224 kW ( 300 HP) in modifications with narrow or wide ratio coverage. As a rule these transmissions are used for commercial vans, drop-side trucks with a manipulator and all kinds of special equipment with a load capacity up to 13.6 tons ( 3000 lb). These transmissions are installed on almost all brands of trucks, buses produced in Europe (except MAN), Korea, and China. The instantaneous connection between the engine and the gearbox ensure precise modes of operation regardless of the cargo condition and the road quality.

Accurate gear shifting without interruptions of power ensures the best speed characteristics and fuel economy. Fully automatic transmission allows the driver to pay more attention the driving process that is more important in difficult and tedious road conditions. The transmission electronics can be programmed to prohibit the vehicle movement when the auxiliary equipment is used. Consequently, the auxiliary equipment will be inaccessible when the vehicle moves. This feature provides additional security in operation.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT		841	14	10	Allison TES 295

Technical issues and repair guidelines

The main repair problems are related to the auxiliary power take-off equipment, torque dividers, and the main one – the cooling process or heat exchanger. Designers of these transmissions quite consciously reduced the transmission resource by means of cooling.

There are 3 main problems related to valve bodies of Allison 1000/2000/2400:

1. Sticking E-shift. When the valve sticks TCM detects that the pressure sensor doesn’t change the status and sets the trouble code P0872- after that the gearbox switches to the failsafe mode.

2. F-trim valve sleeve. The inside diameter of the sleeve wears out, leading to the torque converter clutch surge and trouble code P0741 – indicating the torque converter clutch slipping. . When lock-up stops operating and the P0741 code sets, the torque converter can overheat the ATF, causing damage to the torque converter and rapid deterioration of the ATF.

3. Warped castings. Valve bodies for these transmissions do not have separator plate gaskets, therefore it is required that two halves of the valve body should be flat sanded for protection from cross leakages. In this case locating pins should be removed to flat sand the valve body.

How to repair this transmission (Videos)

fluid and filter change

Allison Transmission Assembly

Instruction manuals and useful links

Link type	Source	Description
web	all-trans.by	Identifying Allison 1000/2000/2400 Valve Bodies

POWERGLIDE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The Powerglide is a two-speed automatic gearbox constructed by GM. This gearbox was mainly installed on Chevrolet vehicles (1950-1973) and on some Pontiac cars. The gearbox was uncomplicated and extremely reliable, that gained trust of customers. In spite of its old-fashioned construction Powerglide is still popular in drag racing (as well as in mud racing) because it is not complicated and robust.

Technical issues and repair guidelines

How to repair this transmission (Videos)

Powerglide Transmission Cutaway

LEARN TO REBUILD THE POWERGLIDE

Instruction manuals and useful links

Link type	Source	Description
web	Sonnax	Understanding & Overcoming the Powerglide Servo Pin Bias Effect

FMX Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The FMX is a fully automatic 3-speed gearbox, ensuring automatic up-shifts and down-shifts via the 3-forward gear ratios. This gearbox also includes manual selection of first and second gears. It is reported that FMX combines in itself the best features of MX and FX modifications.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		10,4	5	Type F

Technical issues and repair guidelines

This is a hydraulically controlled RWD gearbox. In terms of design this unit is close to BW8 and BW12, but spare parts are not interchangeable. FMX consists of the following main components: torque converter, oil pump, input shaft, rear-clutch, front-clutch, compound planetary gear set, rear band, one-way clutch, rear support-oil distributor and parking gear, governor, output shaft, vacuum diaphragm, control valve body, front band. This automatic gearbox was used during 1968-81 in many Ford cars.

How to repair this transmission (Videos)

FMX Transmssion part 1

FMX transmission part 2

Rebuild the Ford FMX Transmission

Instruction manuals and useful links

Link type	Source	Description
web	Wikipedia	Ford FMX
pdf	forelpublishing.com	Diagnosis and service FMX Transmission
0	makcotransmissionparts	Scheme FMX

U540E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed FWD automatic transmission U540E was designed by Aisin in 2000 on the basis of the famous A4LB-1, which went out of fashion by that time. The transmission A4LB-1 also was modified in 2002 and a new modification can be found on different cars worldwide.

This automatic transmission has two names - U540E (according to Aisin Co), and Daihatsu gave different names to its sub-modifications: A4Q, A4P, A4L, A4G, ..., depending on the car model. The U540E was upgraded with several hydraulic control solenoids, the valve body and electrics, and the new filter for the valve body.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		6,2	4	Toyota Type T-IV

Technical issues and repair guidelines

This transmission is very reliable as the most of Aisin transmissions. For many years of operation, it only requires change of oil and filter replacement, however it can cover the distance of 150-200 thousand kilometers even with an old filter. For the overhaul of this carefully adjusted transmission, specialists usually order the repair kit of gaskets and seals, which is mainly needed for reassembly of contaminated valve body and replacement of worn out rings causing the burning of frictions.

The kit of all friction clutches is usually ordered together with the repair kit. Frictions get burnt for various reasons, but one of the most popular ones is related to insufficient oil pressure, caused by:

1. worn-out teflon and rubber rings

2. dirty wedging valves of the valve body

3. dirty valves of solenoids

4. faulty electrics of the solenoid or wiring of solenoids

5. clogged filter

This transmission can be rarely met in repair services, all spare parts for this transmission are considered to be rarity and there is no much statistics related to its repair.

Instruction manuals and useful links

Link type	Source	Description
pdf	alltranz.co	Scheme U540E

K410 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

TOYOTA K410 / K411 / K41A / K41B / XA-10LN

Aisin developed the “200” series (K210) of CVT transmissions in 2002. This gearbox was intended for cars with 1.0-1.3 liter engines. The K210 had been produced and installed on some Toyota cars for the domestic market of Japan before 2015.

Nevertheless, this series was not very successful – the CVT was larger than initially planned; it turned out to be not very convenient for underhood space of small cars. Therefore, in 2004, Aisin started

developing a new “400” series on the basis of the K210. The K410 modification was smaller in size, lighter weight, and had enhanced fuel economy in comparison with the “200” series. Toyota considered the K410 to be an ideal CVT solution for small cars with 1.0-1.3 liter engines. This transmission is still applied in numerous Toyota cars (including cars for the European market).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	145	8	5	Aisin CVTF7004, Toyota 08886-02105

In October 2008, Aisin launched production of the CVT transmission named K41A. This transmission was designed on the basis of the K410 modification and was specifically intended for application on cars Toyota IQ. The main difference between these two transmissions lies in the fact the differential in K41A was moved forward (in contrast with K410). This measure made it possible to reduce the size of the CVT for installation on limited underhood space of Toyota IQ (with 1.0 liter engine).

In April 2009, the CVT modification K41b was launched in production. The main peculiarity of this transmission is higher torque transmission capacity. Therefore, this gearbox could have been used for Toyota IQ with more powerful 1,3-liter engine.

In October 2010, Aisin engineers came up with a new CVT solution for the “400” series – the modification K411. The main difference of the K411 transmission from the 410 version is a significant fuel economy, which is achieved by actuation of an active clutch, when starting a car, and thanks to a new control mechanism (flex start control).

In 2007, Aisin produced a new modification of the K410 transmission, which was named as XA-10LN for external markets (not for Toyota cars). This CVT was successfully applied in Suzuki cars (Suzuki Splash and Suzuki Swift). These Suzuki models were sold in the domestic market of Japan.

In the European automotive market, K410/K411 CVTs were installed only on Toyota IQ (K41a and K41b) and Toyota Verso-S/Subaru Trezia (K411). Cars equipped with CVTs K410 and K411 were not sold in the North America (USA and Canada). Cars with these transmissions are quite popular in Australia, New Zealand, and some countries of Southeast Asia.

Typical problems

Typical problems which occur in this range of CVT transmissions include the following:

1) ATF contamination

2) K410/K411 CVTs often get overheated (especially in winter time)

3) Damage of bearings

4) Seal Clutch leakages

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mazda	DEMIO	07-14	CVT FWD	L4 1.3L 1.5L
Subaru	TREZIA	12-13	CVT F/4WD	L4 1.5L
Suzuki	SPLASH	08-14	CVT FWD	L4 1.2L
Toyota	IST	07-16	CVT F/4WD	L4 1.5L
Toyota	PORTE	11	CVT FWD	L4 1.5L
Toyota	RACTIS	06-13	CVT FWD	L4 1.5L
Toyota	SIENTA	03-15	CVT FWD	L4 1.5L
Toyota	VITZ	05-16	CVT FWD	L4 1.5L

VT20E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The CVT transmission VT20E was used for FWD Opel Vectra of English and German assembly with engine capacity equal to 1.8 liters. The VT25E modification found application in American FWD Saturn VUE and Ion (2.2 liters capacity).

This CVT equipped with a push belt is perfectly adjusted, therefore it rarely gets in repair services. During the first 150-200 thousand kilometers of exploitation, drivers just should not forget to replace filters and change transmission fluid in a timely manner (depending on the driving style).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	175	6,5		VTF DEXRON CVT

Technical issues and repair guidelines

A minimum set of procedures during the overhaul of these CVTs includes the following:

- Belt replacement

- Replacement of all spare parts, gaskets, seals, sealing strips, rings, which often include two pistons

Friction elements of Forward pack often get burnt, including a bearing disc and pistons, the whole set of frictions gets replaced.

Problems of “old” VT25E:

- Valve Body, VT25E CVT.

- Planetary gear, Reverse (6 Gear) .

It is required to replace CVT when cones get worn out (because of aggressive accelerations "at a cold motor" and driving with contaminated oil).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Opel / Vauxhall	VECTRA	02-04	CVT FWD	L4 1.8L

How to repair this transmission (Videos)

Repair cvt VT25-E/VT20-E, Saturn, Opel

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme VT20E
pdf	www.at-manuals.com	Scheme VT25E

U660E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission U660E designed by Aisin in 2006 for FWD cars Lexus ES350, as well as for the luxury 6-cylinder models (Camry, RAV4, Avensis) for 3.5 lit. The unit was paired with the V6 engine.The U660F unit is intended for AWD crossovers and sedans. The U660 unit is a competitor of ZF 6HP26. In 2009, the U660 unit was complemented by U760E model cured from "common problems" and intened for a bit lower torque from the engine (up to 2.7 l). After some period of time the U761E sub-modification was released for less powerful engines with 2.0-liter capacity. Repair parts for this gearbox are the same as for U760. Among the market competitors of the U760 unit, specialists point out the ZF 6HP21 unit.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/AWD		6,5	2,8	Toyota Type WS

Technical issues and repair guidelines

Friction lining of the lockup unit is not the most crucial problem for driving, but it is critical for the “health” of this transmission. The torque converter is the main "contaminator" and the source of all problems of clogged valve body and solenoids. This gearbox usually covers 200 thousand kilometers, but the driver can significantly cut its service life by an aggressive driving style. Almost all major repairs of this gearbox include the torque converter repair. The torque converter repair with replacement of worn-out friction lining every 150-250 thousand kilometers (depending on the driving style) allows saving of some money on the valve body replacement.

According to judgement of experts, the most common problem of the U660E unit is related to the main housing bearing, which is attached to a “weak” circlip. The drum of Direct package is one more problem of this gearbox. Many gearboxes with short mileages (only70-100 thousand kilometers) were handed in for the overhaul and replacement of burnt clutch cover С1-С2 - Drum (Direct) in the assembled condition. Another issue is related to wear-out and burning of frictions in braking packages B1-B3 (gears 2 and 6). The most frequently replaced component is a set of frictions in the package C1/C2 (gears 1-4). Generally the whole set of friction components is replaced.

Valve body and solenoids in U660E

The most common problem for all 6-speed automatic gearboxes is the worn valve body. The problem with the valve body, which operated with damaged torque converter lockup and contaminated ATF, is related to wear-out or slagging of channels and plunger-valves of the valve body. The most frequently replaced component in the electrical part is the selector position plate with temperature sensors. The overheated temperature sensor is often considered to be the reason of the valve body malfunction. The first reason of early issues with electrical components (before covering 200 thousand kilometers) is the automatic transmission overheating. Almost each overhaul of overheated U660E transmission is accompanied with the order of pistons kit. The list of spare parts that may be damaged in this sophisticated gearbox as a result of neglected bearing vibrations is quite large (crown gear, sun gear, planetary gears, differential, pistons).

It should be taken into account, that all abovementioned problems with the U660 unit are common for very old or quite worn-out automatics. A high percentage of cars equipped with U660 serve before covering standard 200 thousand kilometers (in many cases even longer) without any repairs under the condition of timely ATF change and filter replacement.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LEXUS	ES	06-16	6 SP FWD	L4 2.0L 2.5L V6 3.5L
LEXUS	RX	08-15	6 SP F/4WD	V6 3.5L
Lotus	ELISE	12-15	6 SP RWD	V6 3.5L
Lotus	EVORA	10-16	6 SP RWD	V6 3.5L
Toyota	ALPHARD	08-14	6 SP F/4WD	V6 3.5L
Toyota	AVALON	07-16	6 SP FWD	V6 3.5L
Toyota	AVENSIS	08-16	6 SP FWD	L4 2.2L
Toyota	BLADE	08-12	6 SP FWD	V6 3.5L
Toyota	CAMRY	06-16	6 SP FWD	L4 2.0L 2.5L V6 3.5L
Toyota	ESTIMA	06-16	6 SP F/4WD	V6 3.5L
Toyota	HIGHLANDER	09-16	6 SP F/4WD	L4 2.0L V6 3.5L
Toyota	MARK X ZIO	07-13	6 SP F/4WD	V6 3.5L
Toyota	RAV4	12-16	6 SP F/4WD	L4 2.0L 2.2L
Toyota	SIENNA	10-16	6 SP F/4WD	V6 3.5L
Toyota	VANGUARD	11	6 SP F/4WD	V6 3.5L
Toyota	VENZA	08-16	6 SP F/4WD	V6 3.5L
Toyota	VERSO	09-16	6 SP FWD	L4 1.6L 2.2L

How to repair this transmission (Videos)

U660E / U760E Gear Set and Components

U760E with code P2716

U760E TCM

U660E Intro ATRA

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual U660E/F
pdf	www.at-manuals.com	Scheme U660E/F
web	www.at-manuals.com	Check Balls U660E
web	www.at-manuals.com	Stall test U660E
pdf	Sonnax	Valve Body Layout U660E/F, U760E/F

U340E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic gearbox Toyota U340 (U341) has been used since 2000 on FWD Toyota Avensis, Corolla etc. with engine capacity up to 2 liters. One more leading transmission which is commonly met in repair services.This transmission was designed together with U140\ U240 (and identical in design) and was a very popular transmission in the field of repair among Aisin gear shifting units. The modification U341E provides higher torque, therefore it is used in engines with higher operational capacity Celica (1.8 l), the U341F unit is the version for four-wheeled vehicles (4WD).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		8	2,9	Toyota Type WS

Technical issues and repair guidelines

The whole mechanical and hydraulic part of these transmissions is very robust and the service life before the 1-st major repair is above 200-300 thousand kilometers depending on the driving style of auto users. During the first years U340-341 units require timely change of fluid and filter replacement. After some period of operation and due to frictions wear-out (torque converter in particular), the fluid gets contaminated more rapidly and that results in more frequent ATF change. Frequent change of automatic transmission fluid postpones the replacement of the torque converter lining. One of the most common problems is the oil leakage from the pump seal located between the gearbox and the torque converter. The seal is changed together with the bushing.

One of the most common parts to be replaced in new units (produced since 2009) is the EPC solenoid, which operates in much more intensive way than others. This transmission gets out of order after continuous operation in contaminated ATF with worn-out rings and seals. Timely change of ATF and repair of rings included in the repair kit makes it possible for this solenoid to operate during the whole period of the transmission usage period.

Typical issues with valve body and solenoids in U340

The electrical components of this transmission are quite durable, therefore the whole U340 unit may be considered as a very reliable transmission. However, during each disassembly procedure of this gearbox, specialists usually rebuild and clean the valve body and solenoids, which get damaged because of contaminated ATF. The clogged valve body may lead to unpredictable slippage in the package, where the fluid is not transmitted through corresponding valve body plunger. Long-term operation of this transmission with such problem leads to premature wear of practically “invincible” friction components in this unit.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Toyota	ETIOS / VALCO	13-16	4 SP FWD	L4 1.2L 1.5L 1.6L

How to repair this transmission (Videos)

U340E Corolla Valve Body Problems

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual U340
pdf	www.at-manuals.com	Manual U340e
pdf	www.at-manuals.com	Scheme U340E
web	www.at-manuals.com	Stall test U340e
pdf	Sonnax	Valve Body Layout U341E/F
pdf	Sonnax	U341E/F TCC Slip Diagnosis

U140E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Transmission repair specialists frequently have to deal with repair issues in the 4-speed automatic transmissions U140E, U240, U241 and the entire range of these transmissions from Aisin Co. Aisin engineers wanted to design the U140E unit with a potential extension to 5 speeds.In 2000, more enhanced modification named U240 was introduced and a lot of U140\ U240 automatics found application in the whole range of popular Toyota cars at the auto market in Japan.

The U241E (U240E) transmission has been operating safely since 2000 on the front-wheel (four-wheel drive) middle class cars with engine capacity from 2 up to 3 liters.The structure of these automatic units is so robust and sophisticated that even the presence of some soft spots (such as the third planetary gear) does not prevent U240-241 transmissions from being installed on very popular Toyota cars.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD/AWD		9,5	4,2	Toyota Type T-IV

Technical issues and repair guidelines

The risk group of car with this reliable transmission includes heavy cars with 3-liter engines, where gearbox components operate under heavy loads and the 1-st overhaul may occur even before the car travels 200 thousand kilometers. The first component to be repaired is the torque converter. In "old" U140 units transmission specialists have to pay closer attention to the output planet, which may have some issues related to the damage of pinion-satellites axles caused by critical loads. The sun gear gets damaged together with satellites of the planetary gear. At the following stage of damaging process, fragments of the damaged planetary gear crush the rear planetary gear of the U140 unit.

The back cover is the second problematic place for this transmission: it performs a support function in U140-240 design. This issue is common for high-power engines both in RAV-4, and in Camry, Lexus RX300. According to the statistics change of frictions and steel disks in the Direct package is performed 3-4 times more frequently than in any other package.

One more frequently replaced element in the Direct clutch package is the rubber-covered piston with a holder. The rubber gets damaged very fast failing under higher temperatures and dry functioning with jittering. When the pump bushing gets damaged it should be repaired together with the torque converter. The typical problem of the ECU during first years of operation – non-soldered contacts, causing unpredictable burning of packages and pressure jumps. Almost each overhaul includes a preventive change of the pump cup seal on the left side and the left semi-axle seal on the housing side.

The 4-speed automatic transmissions U140E , U240 , U241 from Aisin Co traditionally have very reliable and persistent elecal components. Specialists almost every time are restricted to the repair and cleaning of the valve body and solenoids without any expensive replacements. The repair of old valve bodies involves cleaning of soot deposits and rebuilding of channels used for movement of valves.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LEXUS	ES	99-02	4 SP FWD	V6 3.0L
LEXUS	RX	98-03	4 SP F/4WD	V6 3.0L
Toyota	CAMRY	02-03	4 SP FWD	V6 3.0L
Toyota	ESTIMA	00-06	4 SP F/4WD	L4 2.0L V6 3.0L
Toyota	HARRIER	00-03	4 SP F/4WD	V6 3.0L
Toyota	HIGHLANDER	01-07	4 SP F/4WD	L4 2.4L V6 3.0L
Toyota	KLUGER V	00-03	4 SP F/4WD	V6 3.0L
Toyota	WINDOM	00-02	4 SP FWD	V6 3.0L

How to repair this transmission (Videos)

U140 Teardown Inspection

Part 1-4 2002 Lexus RX300 U140

Part 2-4 2002 Lexus RX300 U140

Part 3-4 2002 Lexus RX300 U140

Part 4-4 2002 Lexus RX300 U140

Instruction manuals and useful links

Link type	Source	Description
pdf	Valve Body Pro	U140 Shifting Pre Info
pdf	www.at-manuals.com	Scheme U140
pdf	www.at-manuals.com	Manual U140
pdf	Sonnax	Valve Body Layout U140E/F, U240E, U241E
web	Sonnax	Toyota U140E Detailing

TF70SC Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission AT6 (TF-70SC) from Aisin Co was designed in 2006 for FWD Peugeot cars of the middle class with the engine from 1.6 to 2 liters. This transmission has the torque capacity of up to 220 Nm (according to Aisin). After a long testing this automatic transmission was launched in the mass production in 2009, but was produced not as actively as the TF80 transmission unit. It was developed for Peugeot-Citroen cars on the constructive basis of TF-80SC (AM6 High torque capacity- up to 400 Nm). Inner parts of this transmission are similar to TF60-SN. Aisin name is AWF6F25.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD	220	6,1	3,2	Тойота WS

Technical issues and repair guidelines

The transmission AT6 has an electronic control integrated in the design of the transmission. One of the features of these automatic transmissions is the forced control of the torque converter lock-up. This feature, on the one hand, gives an increase in efficiency and rapid acceleration with fuel economy, but, on the other hand, it significantly loads the torque converter and the valve body. In previous versions of transmissions it led to the rapid wear-out of the valve body and the breakdown of solenoids. The transmission is designed as an "invincible" solution and operates till the old age of the car, when the transmission repair no longer makes sense. But violation of simple rules of operation for this automatic transmission can lead to the overhaul only after 150-200 thousand kilometers.

Repair procedures and typical problems

For the first overhaul specialists order the Repair kit of gaskets and seals. This repair kit is ordered mainly because of teflon rings, which wear out primarily from exploitation with contaminated oil and overloads.

The chain of malfunctions starts with the clogged valve body and solenoids, which do not transmit enough oil to the line of one of the packages, therefore the transmission shifts gears with a delay or a kick. One of the typical problems in modern 6-speed automatic transmissions, and in the TF-80SC in particular, is related to the valve body. The valve body is extremely sensitive to the friction suspension from the torque converter in the ATF. Frequent oil changes facilitate the valve body self-cleaning. But now the valve body itself has become almost invincible because all soft spots related to channels transmitting contaminated oil and the plunger with valves have become the part of the solenoid design.

It should be borne in mind, that the higher the wearout level of rings and rubber gaskets, the more ATF should be transmitted by the pump through valves of the valve body in order to compensate losses. Therefore solenoids operating in heavier oil current wear out much faster. For this reason, each reassembly and replacement of solenoids should be accompanied by replacement of spare parts.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Beijingauto	X65	15-16	6 SP F/4WD	L4 2.0L
Citroen	C4	10-16	6 SP FWD	L3 1.2L L4 1.6L 1.8L
Citroen	C4 LOUNGE	13-16	6 SP FWD	L4 1.6L 2.0L
Citroen	C5	09-16	6 SP FWD	L4 1.6L 2.0L 2.2L
Citroen	DS4	11-16	6 SP FWD	L4 1.6L
Citroen	DS5	11-16	6 SP FWD	L4 1.6L
Dongfeng	AX7	14-16	6 SP FWD	L4 2.0L 2.2L
Dongfeng	B20	16	6 SP FWD	L4 2.0L
Dongfeng	L60	15-16	6 SP FWD	L4 1.8L
DS	DS5 LS	14-16	6 SP FWD	L4 1.6L 1.8L
Fiat	500	10-16	6 SP FWD	L4 1.4L
Fiat	500L	14-16	6 SP FWD	L4 1.4L 2.0L
JEEP	RENEGADE	15-16	6 SP FWD	L4 1.7L
MINI	COUNTRYMAN	2012	6 SP FWD	L4 1.6L
MINI	ROADSTER	2012	6 SP FWD	L4 1.6L
Peugeot	3008	09-16	6 SP FWD	L4 1.6L 2.0L
Peugeot	308	09-16	6 SP FWD	L4 1.6L 2.0L
Peugeot	408	12-16	6 SP FWD	L4 1.6L 2.0L
Peugeot	5008	09-16	6 SP FWD	L4 1.6L
Peugeot	508	10-16	6 SP FWD	L4 1.6L 1.8L 2.0L
Peugeot	RCZ	09-15	6 SP FWD	L4 1.6L
Volvo	S60	15-16	6 SP FWD	L3 1.5L L4 2.0L

How to repair this transmission (Videos)

TF-72SC Teardown

AA80E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 8-speed automatic gearbox AA80E (TL-80SN for Lexus) produced by Aisin Co has been installed since 2007 on RWD Lexus LS460 (IS, GS460) and Toyota Land Cruiser and Crown Majesta with engines V8 from 4.6 up to 5.0 liters. The modification АА80F is used for AWD LS460. The maximum torque is up to 550 Nm. In terms of design, this transmission is related to TR-80SD (0С8).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
8	AT	RWD/AWD	550	11,3	3,7	Toyota WS

Technical issues and repair guidelines

With regard to mechnical components typical problems usually occur in the bushing and the pump seal, which are the first to be affected by the torque converter (TC) lock-up wear-out and overheating. The oil leaks via the seal of pump/TC is the the first signal for diagnostics, cleaning of the valve body, and the TC repair. Further operation with such leakages may result in the necessity for the pump bushing replacement, and in some cases replacement of the pump itself.

In the electric part, the first level repair consists of the valve body cleaning and replacement of solenoids. As in many of Aisin automatic transmissions, the torque converter lock-up solenoid SLU is the first to wear out, because this solenoid operates with all contaminated and overheated oil from the worn-out torque converter. Another problematic area is the main pressure solenoid LPC (SLT), which transmits all ATF to other solenoids.

Specialists recommend to monitor closely the ATF condition in the TL-80SN transmission. In case of rapid ATF contamination after the prior partial change, it is recommended to visit the repair shop for the torque converter repair, without waiting for the friction plate wearout, that may be especially harmful for the AA80E solenoids and the valve body. It is also advisable to replace the filter in due time, and check the pan.

The design of transmission components for all RWD Aisin transmissions is considered to be "invincible", having a large structural reserve. This transmission usually operates without serious problems throughout the car lifespan. However to avoid unnecessary repair costs, car owners have to monitor the ATF state, timely visit specialists for the torque converter repair, cleaning of solenoids and the valve body.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Cadillac	CTS	13-16	8 SP R/4WD	V6 3.6L
Hongqi	L7	12-16	8 SP RWD	V12 6.0L
LEXUS	GS	13-16	8 SP R/4WD	L4 2.0L V6 3.5L
LEXUS	GS	08-12	8 SP RWD	V8 4.6L
LEXUS	IS	07-16	8 SP R/4WD	L4 2.0L V6 3.5L V8 5.0L
LEXUS	LS	06-16	8 SP R/4WD	V8 4.6L
LEXUS	RC	14-16	8 SP RWD	L4 2.0L V6 3.5L V8 5.0L
Toyota	CROWN ROYAL	12-16	8 SP RWD	L4 2.0L V6 3.5L

How to repair this transmission (Videos)

Lexus AA80E (Aisin TL-80SN)

TAAT Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

TAAT automatic gearbox was released in 1991 by Saturn LLC. This type of gearbox was mainly used in 1991-UP Saturn S-Series. In terms of design TAAT is a parallel shaft FWD unit with the drive gear. TAAT has 4 forward gears and 1 reverse gear by means of multidisc clutches, 4-element torque converter with a lock-up clutch, 1-st sprag-type clutch, and a tooth clutch activated by a servo unit.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		6,2	4,2-5,2	Dexron VI

Technical issues and repair guidelines

One of the main peculiarities of this transmission in comparison with common automatic gearboxes lies in the electronic control. This gearbox uses 5 solenoids together with the transmission control module and its sensors to control shift timing, shift feel, and give on board diagnostics.

Repair specialists say that the valve body is the most problematic component in TAAT. Delays, slippages, kicks or lack of Reverse during gear-shifting are likely to be caused by valve body issues. However, there are several other sources of a Reverse problem:

1. Delay or no Reverse may be caused by the loose-fitting main shaft nut

2. Malfunctioning car speed sensor may also lead to no-Reverse condition.

3. Wrong adjustment of the pattern select switch

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Saturn	S-SERIES	95-03	4 SP FWD	L4 1.9L

How to repair this transmission (Videos)

Valve Body Removal 1of 2

Valve Body Removal 2 of 2

Solenoid Testing & Replacing

DIY timing chain kit installation

SWRA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

HONDA SWRA / SWSA / SLTA / SLSA / SYEA / SYFA / SFBA / SFCA

The CVT Honda Multimatic SWRA / SWSA had been installed on right hand drive cars Honda Fit of the first generation (produced from 2001 till 2007) for the domestic market of Japan. It should be pointed out that Honda Fit cars for the American market were equipped not with CVTs, but with common automatic transmissions. Therefore, transmissions for Japanese and American models of Honda Fit are not interchangeable.SWRA is a continuously variable transmission produced by Honda. This transmission is used in some Honda cars (Civic, Jazz, Logo).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		5,9	2,5	Honda Multi Matic Fluid

CVTs SWRA / SWSA differ from each other not by engines (with which they operated), but by the purpose of CVT model (for FWD or AWD). In other words, Honda Fit cars with L13A and L15A engines were equipped with the same transmission SWRA / SWSA, but there was an important difference:

- SWRA – 2WD

- SWSA – 4WD

As the right hand drive Honda Fit of the first generation (produced from 2001 till 2007 ) served as a basis for other cars («Honda Airwave», «Honda Mobilio», «Honda Mobilio Spike»), then CVTs for these cars were slightly upgraded (the main difference lied in the housing mounting). These CVTs received new model names:

· Honda Airwave (from 2005 to 2007) 2WD – SLSA

· Honda Airwave (from 2005 to 2007) 4WD — SLTA

· Honda Mobilio/Mobilio (from 2002 to 2005) 2WD — SYEA

· Honda Mobilio/Mobilio (from 2002 to 2005) 4WD — SYFA

· Honda Mobilio Spike (from 2002 to 2005) 2WD — SFBA

· Honda Mobilio Spike (from 2002 to 2005) FWD – SFCA

· Honda Fit Aria / Honda City (from 2002 to 2009) 2WD — SERA

In fact all these car models were equipped with the same CVT. Transmissions differed only in the drive mechanism (FWD or AWD) and in holders for the CVT case. All other components of these CVTs are absolutely identical. Therefore, these CVTs may become interchangeable with the help of several minor modifications. Modifications usually consist in replacement of holders and some sensors.

According to Honda’s manual, SWRA / SWSA transmissions require ATF change вариатора (CVT) every 45 thousand kilometers. When the car operates in harsh conditions ATF should be changed after 22,5 thousand kilometers.

Harsh conditions usually include:

1.Frequent and short drives - no more than 8 km in the summer time or 16 km in the cold season (at negative air temperatures).

2. Operations under conditions of high temperatures (above +32 °C).

3. Long engine operation at idle speed, driving with frequent stops in traffic jams. Towing of the trailer or running on mountainous terrain.

4.Driving on dirty, dusty roads or on the roads which are subjected to treatment with anti-icing compound.

Honda Fit cars of the first generation equipped with CVTs SWRA / SWSA often face problems with the CVT mount, which tears after the car mileage reaches 50-60 thousand kilometers. Symptoms of this problem include the following: increased vibration, kicks at starting from rest/braking. Visual inspection helps to detect this problem. The mount is oil-filled, therefore transmission specialists recommend using original spare parts.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Honda	CITY	00-12	CVT FWD	L4 1.3L 1.5L

How to repair this transmission (Videos)

Honda Civic CVT Transaxle Operation

RE4R03A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission RE4R03A ( RL4R01А/JR403E, RG4R01А) for engines with the capacity from 2 up to 3-liters was produced by Jatco in 1988 for the off-road vehicle Patrol. This transmission made a good impression and after some adjustments in 1999, it became widely used for RWD Nissan models. This gearbox found application on sport cars 300ZX and on Infiniti Q45 with V8 engines.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/AWD		8,7	4	Dexron III

Technical issues and repair guidelines

This transmission is quite reliable as all rear-driven Nissan vehicles. In terms of design, this transmission is similar to RE4R01B\A and R4A-EL produced by Mazda. Repair parts for this gearbox are ordered in very rare cases. Therefore, in most cases owners of cars equipped with this transmission prefer to replace it with a new or used unit, rather then to spare time and money on its repair.

Typical problems of this transmission are similar to problems of the RE4R01A\B transmission. In most cases, repair specialists order the repair kit of gaskets and seals when they have to deal with this transmission. Sometimes, it is required to replace bushings on cars operating under severe conditions. In rare cases, it is necessary to change one of one-way clutches or set of solenoids, which get cleaned more often than replaced. Not complicated repair procedures for this reliable transmission can add several years to its service life.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dongfeng	RUIQI	08-16	4 SP R/4WD	L4 2.5L
Hyundai	PORTER	03-16	4 SP RWD	L4 2.5L
KIA	BONGO TRUCK	04-16	4 SP RWD	L4 2.5L 2.9L
Nissan/Datsun	300ZX	90-97	4 SP RWD	V6 3.0L
Nissan/Datsun	CARAVAN	12-16	4 SP R/4WD	L4 2.5L
Nissan/Datsun	CIVILIAN	00-16	4 SP RWD	L4 3.0L L6 4.2L 4.5L
Nissan/Datsun	FAIRLADY Z	0	4 SP RWD	V6 3.0L
Nissan/Datsun	FRONTIER	99-15	4 SP R/4WD	L4 3.0L 3.2L
Nissan/Datsun	HARDBODY	00-08	4 SP R/4WD	L4 2.4L
Nissan/Datsun	PALADIN	03-16	4 SP 4WD	V6 3.3L
Nissan/Datsun	PATROL	00-14	4 SP RWD	L4 3.0L L6 4.5L
Nissan/Datsun	SAFARI	97-16	4 SP 4WD	L4 3.0L L6 4.2L 4.5L 4.8L
Nissan/Datsun	TERRANO/REGULUS	03-06	4 SP R/4WD	L4 3.0L

How to repair this transmission (Videos)

RE4R03A Transmission Rebuild

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme

RE4F03A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic gearbox RL4F03A / V RE4F03A / B was designed by Jatco in 1990 for FWD Nissan Primera with the engine capacity up to 2 liters. This transmission replaced the previous version RL4F02A with the hydraulic control.

In 1994, another update was made, and a new modification was released in 2000 under the name RE4F03B. The RE4F03A unit turned out to be very popular in accordance with the ratio price / reliability. After 2000, this transmission has been actively installed on the entire range of Nissan vehicles. Now this range of automatic gear shifting units is used for many models of Nissan cars all over the world.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/AWD	240	8,2	3,5	AT-Matic D Fluid

Technical issues and repair guidelines

During each overhaul of this transmission, repair specialists replace the kit of gaskets and seals, which should be changed after a long-time operation to prevent the damage of the rubber elements. But the main repair procedure consists of replacement of rings, because their wearout may have a negative impact on the oil pressure in clutch packages. In most cases, repair procedures lie in cleaning and reassembly of the valve body, replacement of gaskets, spare parts, springs (of shock absorber), and the torque converter repair. Every second repair includes replacement of the solenoids block The issue with worn-out solenoids may lead to fluid shortages in clutch packages and result in slipping of friction clutches, oil burning and later burning of all frictions.

Hard parts of this transmission are very reliable. This gearbox may be considered invincible except for oil leakages from the pump seal (occur after 150 thousand kilometers), which usually says about the wear-out of torque converter spare parts and the pump bushing. It is recommended to change the fluid not according to its period of operation, but according to its transparency.

When this transmission unit in old cars is exposed to "oil starvation", then it may lead the following malfunctions ( in the following order):

- Reverse drum with the piston, wear-out of the surface by the brake band.

- High clutch drum. The shaft cranks, different types of wear-out of the shaft surface and drum. Reverse friction elements are prone to burning

If the fluid state in monitored and solenoids are timely replaced, then this transmission unit will operate properly for a long period of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Infiniti	G20	94-99	4 SP FWD	L4 2.0L
Nissan/Datsun	AD VAN	06-16	4 SP F/4WD	L4 1.2L 1.5L 1.6L 1.8L
Nissan/Datsun	ALMERA/ALMERA TINO	00-06	4 SP FWD	L4 1.8L
Nissan/Datsun	BLUEBIRD SYLPHY	06-16	4 SP FWD	L4 1.6L
Nissan/Datsun	CUBE/CUBE CUBIC	00-09	4 SP FWD	L4 1.3L 1.4L 1.5L
Nissan/Datsun	LATIO	07-12	4 SP FWD	L4 1.6L 1.8L
Nissan/Datsun	MARCH	06-16	4 SP FWD	L3 1.2L L4 1.5L 1.6L
Nissan/Datsun	MAXIMA	01-12	4 SP FWD	V6 3.0L
Nissan/Datsun	MICRA	03-12	4 SP FWD	L3 1.2L L4 1.2L 1.4L 1.6L
Nissan/Datsun	NOTE	05-13	4 SP FWD	L4 1.5L 1.6L
Nissan/Datsun	NOTE	06-16	4 SP FWD	L4 1.6L 1.8L
Nissan/Datsun	NV200	09-16	4 SP FWD	L4 1.5L 1.6L
Nissan/Datsun	PULSAR	00-06	4 SP F/4WD	L4 1.8L 2.0L
Nissan/Datsun	SENTRA	93-12	4 SP FWD	L4 1.3L 1.6L 1.8L 2.0L 2.5L
Nissan/Datsun	SUNNY	97-16	4 SP FWD	L4 1.5L 1.6L
Nissan/Datsun	TEANA	06-08	4 SP FWD	L4 2.0L
Nissan/Datsun	TIIDA	05-16	4 SP FWD	L4 1.6L 1.8L
Nissan/Datsun	WINGROAD	05-16	4 SP F/4WD	L4 1.5L
Samsung	SM3	02-13	4 SP FWD	L4 1.5L 1.6L
Samsung	SM5	00-09	4 SP FWD	L4 1.8L 2.0L V6 2.0L
Venucia	D50	12-16	4 SP FWD	L4 1.6L
Venucia	R30	16	4 SP FWD	L3 1.2L
Venucia	R50	12-16	4 SP FWD	L4 1.6L 2.0L

How to repair this transmission (Videos)

RE4F03A Nissan

RE4FO3B Teardown

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual RE4F03A
pdf	www.at-manuals.com	Service manual RE4F03A
web	www.at-manuals.com	Line pressure specifications RE4F03A

RL4F02A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission RL4F02A and and its modification RE4F02A (produced by Jatco) found application on FWD Nissan models with the engine capacity of approximately 2.0 liters. The RL modification is intended for lower torque from engines 1.6-2.4 lit, while the RE modification had been installed on 3.0 Maxima until 1994. This transmission had been used on Maxima and Pulsar for 5 years, then it was replaced by more sophisticated and low-priced version- RE4F04A and RE4F03A for engines with the capacity of up to 2-lit.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	260	6		Nissan AT-Matic D Fluid

Technical issues and repair guidelines

This transmission is quite reliable, but when it comes to the repair of this transmission is can be quite expensive. Thus, many car owners prefer to replace this gearbox by the used one. The problem of “old” RL4F02A transmissions as in all Nissan gearboxes lies in the electronic control elements. The torque converter lock-up solenoid operates quite intensively and gets out of service very early. It was modified several times.The rest of solenoids should also be changed before they stop operating properly, because it leads to the oil starvation, cranking of bushings, deterioration of drums, planetary gears and pump.

But usually issues are related to general ageing of rubber gaskets and wear-out of friction components, which contaminate valves of the valve body and solenoids, prevent springs from moving valve cores. All this results in such common issues as jolts and stoppages. The wear-out of friction elements initially affects the torque converter lock-up mechanism, then worn-out clutches start slipping at some gears and the car ceases moving uphill. Generally, this transmission is quite reliable and has a high operational reserve. After the reassembly and cleaning, this gearbox can operate on the snow and in off-road conditions for a long period of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Nissan/Datsun	AXXESS	90	4 SP FWD	L4 2.4L
Nissan/Datsun	PULSAR	88-90	4 SP FWD	L4 1.8L

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme RL4F02A

RL3F01A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

RL3F01A is one of the first 3-speed automatic transmissions Jatco (RN3F01A) had been installed года on some rear wheel drive small cars of Nissan (PULSAR, SENTRA, STANZA) since 1982 until 1989. This is the first transmission with introduced forced torque converter lock-up. The family of 4-speed automatic transmissions RL4F01A \ RE4F02A was released simultaneously with RL3F01A and was very popular.RL3F01A is the successor of 3-speed rear wheel drive automatic transmission 3N71B (later modified in L4N71B, JR401E).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD	150	6,1	2,8	AT-Matic D Fluid

Technical issues and repair guidelines

For the overhaul of this automatic transmission (which takes place very rarely) transmission specialists order the following:

-the kit of friction clutches or clutches Forward (when ordering separate parts).

Metal filter which is usually cleaned and washed. Following the above mentioned recommendations may be enough (if the oil is not burnt) to prolong the service lifespan of this transmission for several years.

- repair kit of gaskets and seals (by the time of the overhaul all gaskets are very old, rubber gets damaged and seals start leaking because of long time in service.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Nissan/Datsun	PULSAR	83-90	3 SP FWD	L4 1.5L 1.6L

How to repair this transmission (Videos)

Transmission valve body assembly

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme RL3F01A

RE0F21A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The infinitely variable speed transmission RE0F21A (JF012E) was developed by Jatco in 1999 on the basis of RE0F06A as a CVT solution of the “extra-lite” class with a minimum torque. For several years, this CVT had been installed on Nissan Cube with the engine capacity equal to 1300 cm3. It was also tested on Italian Fiat (DLTC46FHJ1AA) as an automatic alternative for Punto, Albea, Uno and others, which were in production until recent years. In terms of design, this CVT is similar to RE0F10A, JF011E, RE0F06A.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	130	5	2,5	CVT Fluid NS-1

Technical issues and repair guidelines

Repair procedures for this transmission usually involve timely fluid change and sometimes filter replacement. Sometimes it comes to replacement of the belt which fits to some related CVTs from Honda and Mitsubishi. In rare cases, burnt Forward and Reverse frictions get replaced. Frictions get burnt because of worn-out rings and gaskets (Repair kit of gaskets and seals). Burnt fluid damages rubber seals, therefore experts recommend to replace all rings of this CVT RE0F21A in the course of overhaul. The major part of spare parts for repair of this CVT is bought on the market of used spare parts, and repair of this CVT is less frequent than replacement for "used" CVTs.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Nissan/Datsun	CUBE	00-02	CVT F/4WD	L4 1.3L

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme RE0F21A

R4A51 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission R4A51 (V4A51) was used since 1997 for RWD Montero models with engine capacity from 3-liters. In a couple of years, the new 5-speed R5A51 (2000-2006) and AWD V5A51 versions were launched. This family of automatic transmissions competed with RWD AW30-40LE by Aisin.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		9,6	4	SP III

Technical issues and repair guidelines

Commonly, planned overhaul of these transmissions consists in cleaning of the valve body, repair of the torque converter and ATF change. These measures are assumed to be enough for another 2-3 years of proper operation, if gaskets are intact and the oil pressure in packages conforms to requirements.The reassembly of this transmission usually includes not only the repair kit of gaskets and seals, but also the kit of frictions and the kit of steel discs. A rather long-lived clutch of the torque converter lock-up may be exposed to wearout. In some cases, it may operate until 200 thousand kilometers. The untimely replacement of the friction component results in beatings, damage of the pump seal, and later breakdown of the pump bushing.

Typical problems of R4A51 (V4A51)

Filters are clogged with wear-out products and there are two modifications of filters for transmissions applied in RWD cars. The planetary gear (O.D.) rapidly gets out of order under the condition of extreme and frequent loads close to the torque limit. In the process of reassembly, the valve body is washed and may operate properly till the end of the car lifespan. During the first overhaul, specialists replace some solenoids that operate very intensively, namely EPC solenoid and the solenoid of the clutch lock of the V5A51 torque converter operating in the dirtiest and hottest fluid. Input shaft sensors get out of order because of old age, oil contamination by steel shavings, and overheating It is recommended to replace all frictions and the brake band in case of a long-term operation with burnt fluid.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mitsubishi	MONTERO XLS/MONTERO SPORT	01-04	4 SP R/4WD	V6 3.0L 3.5L

How to repair this transmission (Videos)

F4A51 Teardown Inspection

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual R4A51
web	www.at-manuals.com	Scheme R4A51
pdf	drive.google.com	Repair manual R4A51, V4A51, V5A51
pdf	Sonnax	Valve Body Layout V5A51

MHTA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

HONDA MHTA / SPSA / SMLA / SBLA / STYA / SZCA

MHTA / SPSA / SMLA / SBLA / STYA / SZCA CVT models were developed by Honda for usage in their hybrid vehicles. These CVTs were installed on Honda cars for the domestic Japanese market and for markets of the USA and Europe.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		5,8	3,5	Honda Genuine CVT

■MHTA was used on HONDA INSIGHT from 2001 to 2006 with the engine L4 1.3L

■SPSA was used on HONDA CIVIC HYBRID from 2006 to 2012 with the engine L4 1.3L

■SMLA was used on HONDA CIVIC HYBRID from 2006 to 2012 with the engine L4 1.7L

■SZCA was used on HONDA CIVIC HYBRID from 2003 to 2005 with the engine L4 1.3L

■SZCA was used on HONDA FIT HYBRID from 2003 to 2008 with the engine L4 1.3L

■SBLA was used on HONDA INSIGHT from 2010 to 2014 with the engine L4 1.3L

■STYA was used on HONDA CR-Z from 2011 to 2017 with the engine L4 1.5L

These CVTs are very similar in design and have many common internal parts that greatly facilitates their repair.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Honda	INSIGHT	01-06	CVT FWD	L3 1.0L

MB1 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 3-speed automatic transmission Renault MB1 was released in the early 1980-s. This transmission was used for many Renault vehicles, such as Renault 5, 9, 11, 19, Clio and Twingo.

This transmission has 3 forward gears and 1 reverse gear which are combined in the uniform unit with the drive gear and electronically-controlled differential. The oil pump is activated by the engine shaft via the torque converter and transmits the oil under pressure to the gearbox, where it is used as a lubricant and for controlling actuators.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD	150	5,1	3,5	Dexron III

Technical issues and repair guidelines

The most widespread malfunctions of MB1:

• Gear fails to switch on. Any malfunction of solenoid-controlled valves of the hydraulic distributor switches the automatic transmission into emergency mode.

• Oil leakages. In many cases car owners are bothered by ATF leakages. Usually the oil leaks at the junction of the motor and the automatic transmission.

• Critical breakdowns. Low oil level and the pressure loss caused by the valve breakdown lead to burn-out of friction plates.

• Shifting failure. A poor valve body breaks before reaching 100 thousand kilometers. This problem has the following symptoms: jerks, kicks and failure of some gears.

According to transmission repair specialists the resource of this transmission is equal to 100 - 150 thousand kilometers, but it is very unlikely that this transmission will cover such distance without any repairs.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Renault	R19	00-01	3 SP FWD	L4 1.4L

How to repair this transmission (Videos)

How to make the maintenance

K310 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

TOYOTA K310 / K310F / K311 / K311F / K312 / 313

In 2006, Aisin started production ofCVTs of the K310/K311 series. From Toyota’s perspective, this gearbox was a great option for 1.5-1.8 liter gasoline engines. In November 2008, Toyota cars (Toyota Avensis and Toyota Verso), equipped with the K311, appeared on the European market. In 2012, Aisin improved these CVTs (primary from the point of view of fuel economy) and released a new CVT of this family named as K312/K313.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	175	7	4	Aisin CVTF7004, Toyota 08886-02105

Earlier, each Toyota car model was equipped with a particular CVT from the beginning till the end of its production cycle. With regard to CVTs of “300” series the situation changed. In fact, the K310 CVT model was manufactured until 2015. However in 2012, more modern CVT K313 replaced K310 on some car models (for domestic market). In 2015, Toyota models (Toyota Avensis and Toyota Verso) for the European market were equipped with the K313 CVT instead of K311. The same changes concerned Toyota Corolla.

Typical problems of These CVTs are similar to issues which occur in the “200” series (ATF contamination, overheating, damage of bearings, seal leakages).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Subaru	TREZIA	10-16	CVT F/4WD	L4 1.5L
Toyota	ALLION	07-16	CVT FWD	L4 1.5L
Toyota	AURIS	12-16	CVT 4WD	L4 1.5L
Toyota	COROLLA	12-16	CVT 4WD	L4 1.5L
Toyota	IST	07-10	CVT F/4WD	L4 1.8L
Toyota	PORTE	12-16	CVT F/4WD	L4 1.5L
Toyota	PREMIO	07-16	CVT FWD	L4 1.5L
Toyota	RACTIS	10-16	CVT F/4WD	L4 1.5L
Toyota	RUMION	07-15	CVT FWD	L4 1.5L
Toyota	WISH	09-13	CVT FWD	L4 1.8L

How to repair this transmission (Videos)

Component and Operation CVT K311 K111

K310-K311 CVT Altis Repair

RE7R01A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 7-speed automatic transmission RE7R01A with longitudinal positioning for rear drive (according to Jatco classification - JR710E) was produced by Jatco. It was unitized since 2009 with all engines of Infinity and Nissan from V6 3.0 liters up to V8 5.6 liters (RE7R01B \ JR711E). In addition to Infinity, this transmission is installed on the following SUVs: Nissan Fuga, Pathfinder, Patrol etc.The modification named RE7R01B (Patrol/ QX56/ M56) is intended for high torque models (up to 600 Nm), in contrast with 400 Nm for the RE7R01A.RE7R01A model is a worthy competitor on price and fuel economy with transmissions produced by Aisin and ZF. There are possibilities for the mode of fast and economical car acceleration with switched on "slippery" of the torque converter clutch.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	AT	RWD/AWD	400	9,2	5	NISSAN Matic S

Technical issues and repair guidelines

Like in all RWD automatic transmissions of Jatco, the design of RE7R01A elements implies a very long resource for this gearbox under the condition of preventing operation with contaminated fluid, which leads to the chain reaction: contaminated oil results in worn-out teflon rings, clogged valve body, worn-out solenoids leading to oil starvation of frictions.

It is common to replace torque converter spare parts in the course of overhaul of this transmission. Traditionally, the JR710 reassembly includes the repair kit of gaskets and seals. All rings, gaskets, and seals get replaced. The brake pack В3 (2-3-4-6) is the first to sense reduced oil pressure. Frictions with steel discs get burnt. The pack of С1 (Input) frictions is the second to get burnt. In this case, it is required to replace the whole set of frictions. Regular cleaning of the valve body and repair of the torque converter are performed together with replacement of the hydraulic clutch frictions. Problems in the RE7R01 electrical part are related to the valve body and the control unit.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Infiniti	EX/QX50	08-16	7 SP R/4WD	V6 2.5L 3.5L 3.7L
Infiniti	EX35	11	7 SP R/4WD	V6 3.5L
Infiniti	FX	08-16	7 SP R/4WD	V6 3.0L 3.5L 3.7L
Infiniti	FX35	09-12	7 SP R/4WD	V6 3.5L
Infiniti	G	08-15	7 SP R/4WD	V6 2.5L 3.7L
Infiniti	G/Q60	08-16	7 SP R/4WD	V6 2.5L 3.7L
Infiniti	G25	10-12	7 SP R/4WD	V6 2.5L
Infiniti	G37	09-12	7 SP R/4WD	V6 3.7L
Infiniti	M/Q70	10-16	7 SP R/4WD	V6 2.5L 3.5L 3.7L
Infiniti	M35	9	7 SP R/4WD	V6 3.5L
Infiniti	M37	09-12	7 SP R/4WD	V6 3.7L
Infiniti	Q50	13-16	7 SP R/4WD	L4 2.0L V6 3.0L 3.7L
Infiniti	Q60	16	7 SP R/4WD	V6 3.0L
Infiniti	Q70	16	7 SP R/4WD	V6 3.0L
Infiniti	Q70L	12-16	7 SP R/4WD	V6 2.5L 3.0L 3.7L
Renault	1T PICKUP	16	7 SP R/4WD	V6 4.0L

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Solenoid/component application chart
web	www.at-manuals.com	Transmission breakdown illustration

JR405E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic gearboxes RC4A-EL for RWD and AWD vehicles with engines 1.6 – 3 lit. were designed in 1999 for Mazda and Nissan on a Japanese market. It was frequently installed on RWD models Isuzu and Suzuki.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/AWD	300	8,7		AT-Matic J

Technical issues and repair guidelines

Old cars with the mileage higher than 150 thousand kilometers commonly get some linehaul external filter cut in the oil cooling line by specialists in order to refine quickly contaminating oil and protect solenoids and the valve body. After travelling more than 200 thousand kilometers, it is necessary to repair the torque converter for saving the pump and the bushing. This transmission is quite rare and reliable unit, for which it is necessary to change fluid and monitor conditions of gaskets and seals on a timely basis. It is a common case to order solenoids and sometimes repair kits of gaskets and seals for major repairs of this transmission.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	COLORADO	04-11	4 SP R/4WD	L4 2.4L 2.8L 3.0L
Isuzu	ADVENTURE MASTER	03-07	4 SP RWD	L4 3.0L
Isuzu	D-MAX	02-13	4 SP RWD	L4 3.0L
Isuzu	GRAND ADVENTURE	00-03	4 SP RWD	L4 3.0L
Isuzu	MU-X	13-16	4 SP 4WD	L4 3.0L
Isuzu	SPACE CAB	00-03	4 SP RWD	L4 3.0L
Mazda	BONGO	99-16	4 SP R/4WD	L4 1.8L 2.0L
Santana	300/350	05-08	4 SP RWD	L4 1.6L
Suzuki	VITARA	00-05	4 SP RWD	L4 1.6L

How to repair this transmission (Videos)

JR405E Transmission Rebuild

Instruction manuals and useful links

Link type	Source	Description
pdf	ukrtrans.biz	Repair manual RC4AEL
pdf	automaticchoice.com	Scheme JR405E

RE4R01A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission RE4R01A\B (medium-duty class) RL4R01A (JR402A) found application in RWD and 4WD vehicles (Pathfinder, PickUp X-Terra) with engine capacity from 2 up to 4.5 liters. This gearbox rarely fails and traditionally is considered to be an “invincible” RWD transmission. The RE4R01A\B transmission was produced by Jatco-Nissan in 1987. The design of this transmission was updated several times and as a result it got an electronic control unit (and letter Е in its name instead of hydraulic "L" - RL4R01A). All these modifications have the same structural design and differ in only in some spare parts.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/AWD		6,9	3,1	Matic-D

Technical issues and repair guidelines

The overhaul of this transmission is commonly performed after running 250-400 thousand kilometers. Well-timed and correct reassembly of this system adds a significant resource to the whole unit. In the course of reassembly, it is required to clean the valve body and fix the worn-out torque converter. Another measure is to check and replace spare parts - gaskets, rings, friction components.The package High typically is the first to get burnt. The kit of gaskets and seals (Overhaul kit) is a common order for the overhaul procedure.

Each repair of the "old" RE4R01A involves replacement of the following components:

- Brake band Overdrive 37 mm (Low-Reverse)

- Set of 4 solenoids (together with replacement of the torque converter spare parts).

The first hard part to exhaust its solid resource is the assembled planetary gear (Rear-Front) and burning High package. Worn solenoids cause insufficient oil pressure almost unnoticeable while driving, but results in wearout of all bushings and burning of friction components.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	EVEREST	03-15	4 SP R/4WD	L4 2.5L
Infiniti	J30	92-97	4 SP RWD	V6 3.0L
Infiniti	M30	90-92	4 SP RWD	V6 3.0L
Infiniti	QX4	97-03	4 SP 4WD	V6 3.3L 3.5L

How to repair this transmission (Videos)

RE4RO1A Teardown

RE4R03A Transmission Rebuild

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme RE4R01A

JF405E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed JF405E automatic transmission with the east-west mounting (its forerunner is JF402E) was produced by Jatco in 2000 for the mini cars of the Korean FWD family Hyundai-Kia-Daewoo. The JF405E is used on FWD cars Daewoo / Chevrolet, Kia and Hyundai with the engine capacity up to 1.1 liters. The most common models to be found in repair services are Daewoo Matiz and Kia Picanto.In terms of design, this automatic transmission is related to the 4-speed SR410 (SR412, SR413) designed by Jatco in 1998, on order of Suzuki for Wagon R, and then installed on Alto, therefore many spare parts are interchangeable.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		7,5	4	JWS 3314

Technical issues and repair guidelines

The most common repair procedure for this CVT is the transmission reassembly with replacement of gaskets and seals (Overhaul kit) which are different depending on years of production – before 2003 and after 2003.The most common order this transmission is a budgetary repair kit of gaskets and seals. A standard order on the transmission reassembly also includes the kit of friction components.

Suzuki repair lies in procedures preventing oil leakages, namely the pump seal replacement. This procedure should be accompanied by the pump bushing replacement. One more required measure is the torque converter repair, which has a worn-out locking mechanism, which causes vibrations, hub heating, and damage of the pump seal.

In many cases, owners of JF405E-equipped cars with dirty valve bodies just replace EPC solenoid . This solenoid operates more intensively than others, has no pre-filter from dirt in ATF and wears out earlier. Worn-out rings are usually replaced together with the abovementioned solenoid because leakages in these rings result in lower oil pressure in packages. Old JF405E usually have problems with planetary gears (front and rear).The main pressure solenoid (EPC) is the first to get out of order in the electrical part, then comes solenoid of the torque converter lock-up.

Generally, it’s a very reliable and long-serving transmission where the major part of overhauls lies in the replacement of solenoid, replacement of the valve body, rubbers, sealing rings from the repair kit. It is also required to change the friction lining of the torque converter, which is the "enemy" №1 to the cleanness of ATF and the valve body.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	SPARK	03-13	4 SP FWD	L3 0.8L 1.0L
Chevrolet/GM	SPARK	09-16	4 SP FWD	L4 1.0L
Daewoo	MATIZ	05-15	4 SP FWD	L3 0.8L L4 1.0L
Hyundai	ATOZ	98-14	4 SP FWD	L4 1.1L
Hyundai	SANTRO	00-07	4 SP FWD	L4 1.1L
KIA	MORNING	04-10	4 SP FWD	L4 1.0L 1.1L
KIA	PICANTO	06-09	4 SP FWD	L4 1.0L
KIA	VISTO	00-03	4 SP FWD	L3 0.8L
Maruti-Suzuki	A-STAR	10-14	4 SP FWD	L3 1.0L
Nissan/Datsun	MARCH	02-06	4 SP FWD	L4 1.0L
Opel / Vauxhall	AGILA	00-06	4 SP FWD	L4 1.0L
Suzuki	ALTO	04-14	4 SP F/4WD	L3 0.7L
Suzuki	CERVO	07-10	4 SP F/4WD	L3 0.7L
Suzuki	CULTUS	00-03	4 SP FWD	L4 1.3L
Suzuki	KEI	00-10	4 SP FWD	L3 0.7L
Suzuki	LAPIN	02-15	4 SP F/4WD	L3 0.7L
Suzuki	MR WAGON	02-11	4 SP F/4WD	L3 0.7L
Suzuki	PALETTE	08-11	4 SP F/4WD	L3 0.7L
Suzuki	WAGON R	00-12	4 SP F/4WD	L3 0.7L

How to repair this transmission (Videos)

J405E internals

Valve body repair JF405E

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme JF405E
web	autocats.ws	SCHEMATIC DIAGRAMS JF405E

JF404E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission JF404E of the class "mini" was produced by Jatco in 2000 for FWD vehicles with engine capacity from 1.3 up to 1.6 liters. The JF404E unit is usually installed on Nissan, Suzuki (Ignis and Wagon). This transmission was designed on the basis of SR410 (SR412) used in Suzuki Wagon R and JF405E for engines with a lower torque and related transmission of the "middle" class JF403E for engines up to 2.5 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	150	7,5	4	Matic Fluid D

Technical issues and repair guidelines

The valve body has two modifications. The first one has 6 solenoids and higher demand on the market. Solenoids are simple “on-off” electrovalves with a ball, they operate properly during the whole service life of the transmission, even if channels are worn-out by contaminated ATF. There is also a rare modification with the angled filter and 5 solenoids (the second type of the valve body).

Vulnerabilities and repair procedures

Soft spots of old JF404E transmissions are similar to vulnerabilities of JF405E units. But the main reasons for overhauls are related to overall contamination and aging of the transmission, the torque converter wear-out, accumulation of friction dust in the valve body, wear-out of friction elements. If a driver notices problems with the gearbox at the proper time, then the repair procedure involves the valve body cleaning, solenoids washing, torque converter repair. Usually implementation of these procedures adds several years to the service life of the transmission.

When dirty valves of the valve body operate for a long period of time, then wear-out of housing channels of the valve body leads to harmful ATF overflows and necessity to change the whole valve body or more often change of the whole transmission unit. Rare overhauls lie in the gearbox reassembly and replacement of the overhaul kit – repair kit of spare parts, consisting of teflon rings, gaskets, and seals. This transmission is very reliable, not complex in the repair. When monitoring fluid cleanness, preventing a smell of burning, then the transmission will operate for many years without serious problems.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	LASER	00-06	4 SP FWD	L4 1.5L
Isuzu	GEMINI	0	4 SP FWD	L4 1.5L 1.6L
Nissan/Datsun	ALMERA	00-06	4 SP FWD	L4 1.6L
Nissan/Datsun	NV	00-06	4 SP FWD	L4 1.5L 1.6L
Nissan/Datsun	PULSAR	00-12	4 SP FWD	L4 1.5L 1.6L 2.0L
Nissan/Datsun	RASHEEN	00-01	4 SP F/4WD	L4 1.5L 1.8L
Nissan/Datsun	SENTRA	00-09	4 SP FWD	L4 1.3L 1.6L 1.8L
Nissan/Datsun	SUNNY	00-04	4 SP FWD	L4 1.3L 1.5L 1.6L 1.8L
Nissan/Datsun	TIIDA	12-16	4 SP FWD	L4 1.6L
Seat	AROSA	00-04	4 SP FWD	L4 1.4L
Seat	CORDOBA	02-07	4 SP FWD	L4 1.4L
Seat	IBIZA	01-08	4 SP FWD	L4 1.4L
Skoda	FABIA	01-08	4 SP FWD	L4 1.4L
Suzuki	IGNIS	04-07	4 SP FWD	L4 1.5L
Suzuki	WAGON R	00-04	4 SP FWD	L4 1.3L
Volkswagen	LUPO	00-05	4 SP FWD	L4 1.4L
Volkswagen	POLO	01-07	4 SP FWD	L4 1.4L

Instruction manuals and useful links

Link type	Source	Description
pdf	ukrtrans.biz	Technical manual JF404E
pdf	alltranz.co	Scheme JF404E

RE4F04A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission RE4F04A was designed by Jatco in 1993 for 3 liter Maxima using the experience of the JF403E gearbox which was created in 1990 for Isuzu. Later this transmission was installed on other popular Nissan and Infinity models with engine capacity up to 3 liters. At the same time, another modification RE4F03A was released for lower torque from engines with the capacity up to two liters. This family of 4-speed automatic transmissions is used on FWD vehicles with engines from 2 up to 3 liters. Experts call this gearbox as " the 04-th Nissan", which is considered to be Jatco's achievement in terms of reliability and price.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	290	9,5	4,5	Nissan Matic-D

Technical issues and repair guidelines

RE4F04A is the most popular Nissan gearbox in repair services, which is called "the 4-th Nissan" according to the professional slang.

Typical repair procedures for old automatic gearboxes RE4F04\ LJ4A-EL

In addition to the common set of repair parts for reassembly of the old RE4F04A, it is required to replace the friction lining of the torque converter lockup. When using a powerful engine, the torque converter of this transmission damages its clutch coupling. The lock-up mechanism, damaged till the glue layer, clogs the valve body and gives severe vibrations on the pump shaft, damaging both the pump seal and the pump itself. The first sign of the faulty torque converter is a leaking seal.

Repair of torque converter

In these Jatco transmissions, the brake band may be considered as the spare part of the first priority. The brake band is replaced together with change of frictions in the High package. All friction elements get replaced if the car comes in the repair service with burnt fluid. Many repair parts of the JF506E transmission can be used for repair of RE4F04A. Typical problem element of this transmission is the rear planetary gear. When driving for a long period of time with worn-out torque converter and leaking pump seal, you can face the problem of worn-out pump cover bushing. Another common component to be replaced is the set of solenoids in the RE4F04 unit. Solenoids operate under different load, pair of the most extensively operating solenoids is the first to exhaust its resource from the whole block, but they are replaced altogether. High Clutch and Forward Clutch get out of order in most cases.

In general, this transmission has a significant reserve, allowing drivers to use the potential of this transmission to the fullest. It gets out of order only when the pan already contains much of metal chips and shavings. Under the condition of well-timed torque converter repair and maintenance services, this transmission can serve for incredibly long periods of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	ESCAPE	12	4 SP F/4WD	L4 2.3L
GEO	STORM	90-93	4 SP FWD	L4 1.6L 1.8L
Isuzu	IMPULSE	90-92	4 SP FWD	L4 1.8L
Mazda	MPV (VAN)	00-02	4 SP F/4WD	L4 2.5L V6 2.9L
Nissan/Datsun	MAXIMA	00-02	4 SP FWD	V6 3.0L

How to repair this transmission (Videos)

RE4FO4A Teardown

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual RE4F04A
web	www.at-manuals.com	Stall test RE4F04A
web	Sonnax	RE4F04B Solenoid Identification

JF016E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In 2012, Jatco released the next generation of CVTs named as CVT8- JF016E to replace its best-selling JF011E. Firstly, Jatco tested CVT7-JF015E for classes "mini" and "micro" with engine capacity from 0.7 up to 1.6 liters. And when it became apparent that new features allow this gearboxes to be installed on vehicles with engines up to 1.8 liters, JF016E version was introduced for medium and premium class vehicles with engines up to 2.5 liters. Since 2014, this CVT entered production, and completely replaced its predecessor JF011E.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		8	4,5	CVT Fluid NS-3

Technical issues and repair guidelines

The valve body of the CVT8 unit has a reduced number of valves. The torque converter lock-up zone was expanded,allowing to improve acceleration and fuel saving characteristics, but on the other side the lock-up clutch wear-out leads to rapid contamination and necessity to repair the torque converter.

Repair procedures

During the first years after release of the series, Jatco engineers adjusted the TCM settings in such a way that they allowed loading of CVT components to the limit to attract potential buyers with enhanced acceleration dynamics. Therefore, the valve body replacement may occur during the warranty period. The design of JF016E components is very similar to the JF011E unit. Thus, it is expected that this CVT will be “invincible” on vehicles with engines up to 2.4 liters and that CVT on Nissan Murano with 3.5 liter engine will frequently appear in repair services.

During the first years of operation, repair specialists have to replace the oil filter-cartridge. This filter-cartridge is installed in the heat exchanger and maintains the "right" fluid level in the pan. Cone bearings are considered to be another vulnerable place in this CVT as in its predecessor. Bearings for the next JF017E modification were significantly improved. Problems may occur with the pump JF016E- 017E, which has fewer components in comparison with JF011, but operates as intensive as its predecessor. This CVT is also sensitive to contaminated and overheated transmission fluid.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	CITY EXPRESS	14-16	CVT FWD	L4 2.0L
Dongfeng	MX6	15-16	CVT FWD	L4 2.0L
Dongfeng	YUMSUN	15-16	CVT FWD	L4 2.0L 2.5L
Mitsubishi	DELICA D:5	14-16	CVT F/4WD	L4 2.0L 2.4L
Mitsubishi	LANCER	13	CVT FWD	L4 1.8L 2.0L 2.4L
Mitsubishi	OUTLANDER	14-16	CVT F/4WD	L4 2.0L 2.4L
Mitsubishi	RVR	12-16	CVT F/4WD	L4 1.6L 1.8L 2.0L
Nissan/Datsun	ALTIMA	12-16	CVT FWD	L4 2.5L
Nissan/Datsun	ELGRAND	13-16	CVT F/4WD	L4 2.5L
Nissan/Datsun	JUKE	13-16	CVT F/4WD	L4 1.6L
Nissan/Datsun	MURANO	15-16	CVT 4WD	L4 2.5L
Nissan/Datsun	NV200	13-16	CVT FWD	L4 2.0L
Nissan/Datsun	PATHFINDER	13-16	CVT F/4WD	L4 2.5L
Nissan/Datsun	PULSAR	14-16	CVT FWD	L4 1.2L 1.5L
Nissan/Datsun	QASHQAI	13-16	CVT F/4WD	L3 1.2L L4 1.2L 2.0L
Nissan/Datsun	ROGUE	13-16	CVT F/4WD	L4 2.0L 2.5L
Nissan/Datsun	SYLPHY	12-16	CVT FWD	L4 1.6L 2.0L
Nissan/Datsun	TEANA	12-16	CVT F/4WD	L4 2.0L 2.5L V6 2.5L
Nissan/Datsun	TEANA VIP	13-16	CVT FWD	L4 2.0L 2.5L
Nissan/Datsun	TIIDA	13-16	CVT FWD	L4 1.6L
Renault	CAPTUR	16	CVT F/4WD	L4 2.0L
Renault	CLIO	12-13	CVT FWD	L4 1.5L
Renault	FLUENCE	14-16	CVT FWD	L4 2.0L
Renault	KADJAR	16	CVT F/4WD	L4 1.2L 2.0L
Renault	LAGUNA	16	CVT FWD	L4 1.2L 1.3L 1.6L 2.0L
Samsung	LAGUNA	16	CVT FWD	L4 2.0L
Samsung	QM5	16	CVT FWD	L4 1.6L
Samsung	SM3	16	CVT FWD	L4 2.0L
Suzuki	SX4 S-CROSS	13-16	CVT F/4WD	L4 1.6L
Suzuki	VITARA	15-16	CVT FWD	L4 1.4L
Venucia	T70	15-16	CVT FWD	L4 2.0L

Instruction manuals and useful links

Link type	Source	Description
pdf	automaticchoice.com	Scheme JF016E

JF015E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In 2010, Jatco produced the next generation of CVTs named as CVT7-JF015 (RE0F11A) to replace its predecessor JF011E. In terms of design, this CVT is significantly distinct from JF011E. The JF015 unit also has the torque converter (TC), that reduces the load on shafts, planetary gear for the back run, but the primary peculiarity lies in two forward motion speeds and 3 friction clutch packages: Direct №1(Low), - №2(High) and Reverse.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD		8	4,5	CVT Fluid NS-2

Technical issues and repair guidelines

This construction may be regarded as a mixture of CVT and 2-speed transmission, that allows reducing cones by exceeding the gear ratio by means of two forward gears. As JF015E, this transmission has been used on Suzuki Swift, Splash, Alto, and on some Mitsubishi cars since 2012.

Common problems of the JF015 unit are similar to issues of its predecessor JF011. In most cases, problems occur after significant mileage and may be characterized as "spare parts wear-out". The most urgent repair procedure for CVTs is the replacement of teflon rings, which are replaced together with the input shaft repair and replacement of frictions, replacement of bearings, or change of the belt caused by the exploitation with worn-out rings which rapidly decreases the resource of all these parts. A common issue of JF015 is the input shaft bearing failure. The main shaft is considered to be a soft spot leading to the abovementioned problem.

This transmission is sensitive to contaminated and cold ATF. Frequent usage in winter time with oil temperature below +60 results in slipping and damage of the belt and cones. The belt is a common spare part for all “ageing” Jatco units. Well-timed replacement of the belt having still operating protector helps to prolong the resource of cones, which are considered to be the most important and high-priced unit of the CVT design.

Another frequently replaced component of JF015E is the damaged sun gear. The wear-out of solenoids occurs because of ATF contamination caused by the wear-out of rings and seals, forcing the pump to transmit increased ATF volume in order to make up for shortage of pressure on clutches. Therefore, solenoids are replaced together with all gaskets and rings. The issue of input and output shaft bearings is expected to occur when driving with a slipping belt.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	SPARK	12-16	CVT FWD	L3 1.0L L4 1.0L 1.2L 1.4L
Citroen	RVR	12	CVT FWD	L4 1.6L
Maruti-Suzuki	SWIFT	14-16	CVT FWD	L4 1.2L
Mazda	CAROL	15-16	CVT F/4WD	L3 0.7L
Mazda	FLAIR	16	CVT F/4WD	L3 0.7L
Mazda	FLAIR CROSSOVER	14-16	CVT F/4WD	L3 0.7L
Mazda	FLAIRWAGON	12-16	CVT F/4WD	L3 0.7L
Mitsubishi	ATTRAGE	13-16	CVT FWD	L3 1.0L 1.2L
Mitsubishi	EK SPACE	14-16	CVT F/4WD	L3 0.7L
Mitsubishi	EK WAGON	13-16	CVT F/4WD	L3 0.7L
Mitsubishi	FORTIS	14-16	CVT FWD	L4 1.8L
Mitsubishi	I	12-13	CVT FWD	L3 0.7L
Mitsubishi	LANCER	13	CVT FWD	L4 1.5L 1.6L
Mitsubishi	MIRAGE	12-16	CVT FWD	L3 1.0L 1.1L 1.2L L4 1.3L
Mitsubishi	RVR	13-16	CVT F/4WD	L3 1.2L L4 1.6L 1.8L
Mitsubishi	TOPPO	13	CVT FWD	L3 0.7L

How to repair this transmission (Videos)

Teardown and Failure Analysis - Part 1

Teardown and Failure Analysis -Part 2

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout JF015E (RE0F11A)
pdf	Sonnax	Vacuum Test Guide JF015E

JF010E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The constantly variable transmission (CVT) RE0F09A/B (also named as JF010E – according to Jatco classification) is designed on the basis of famous RE0F06A, but for higher torque of Nissan engine with capacity equal to 3.5 liters V6 and since 2002 it has been used on Nissan Murano, and later (2007) modification for rare Maxima, Pressage, and for some time past installed on Teana of the Russian assembly.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD/AWD		10,1	6	CVT Fluid NS-2

Technical issues and repair guidelines

The delicate usage with a long oil heat-up and frequent oil change (NS-2) accompanied by the torque converter repair is the best way for a car owner to preserve CVT during the first years of operation.

Typical problems of “old” CVTs RE0F09A:

In general, this CVT family is one of the most reliable in the world and these transmissions have been a standard in the world of transmission manufacturers for a long period of time. But this CVT lost competition on the market of 3-4 liter cars to automatic gearboxes and even to DSG. The typical overhaul of this CVT requires the torque converter repair. Common problems of “old” CVTs are related to the pressure control valve (of the pump) wedging caused by overheating and contamination in summer time. The valve can wedge and switch-on after a heat-up, that leads to the dynamic load on transmission components and rapidly damages the belt and cones.

The long-term operation with contaminated oil wears out valves and plungers of the valve body. The most popular spare part for JF010E is a driving belt. The first reason of rapid belt wear-out is related to insufficiently warmed up transmission in winter time. The second reason of the belt damage is the driving at low speeds in traffic jams with harsh accelerations. The most common reason of damage for surfaces of the belt and shafts is related to the oil cleanness.

- Forward Clutch is exposed to burning in most cases. It is also common to replace Reverse clutches.

- Sometimes orders for repair include the step-motor which has quite limited operational life in overheated oil ( as in JF011).

The main factor for operational durability of this transmission is related to the state of shafts (input and output) which are unique in terms of design. The surface of cones is the main resource of this transmission. All other units of this gearbox are much cheaper or easily operate during two service lives of this CVT.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Renault	MEGANE	09-11	CVT FWD	L4 1.9L
Renault	SCENIC	09-11	CVT FWD	L4 1.9L

How to repair this transmission (Videos)

Murano CVT Transmission Repair Part 1

Murano CVT transmission Repair Part 2

Murano cvt transmission repair part 3

Murano cvt transmission repair Part 4

CVT transmission repair Part 5

CVT Transmission Repair Part 6

Instruction manuals and useful links

Link type	Source	Description
0	Sonnax	Valve Body Layout JF010E (RE0F09A)

KM175 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Standard automatic transmissions KM175-5, 176, 177-5,6,7/8 (another name- F4A21-F4А22) found application in FWD Mitsubishi cars. This transmission has been installed on Mitsubishi Galant, Sonata,...etc since 1988. It was developed on the basis of a successful 3-speed family KM170. This family of FWD automatic transmissions was actively installed on Hyundai Elantra, Sonata, Excel etc. It was also installed on budgetary cars Dodge, Plymouth, etc. The new series of 4-speed automatic transmissions named as A4AF-1 (and its modification A4AF-2, A4BF-2) was designed by Hyundai AT-department under the supervision of Mitsubishi in 1992 on the basis of КМ175 series for small cars Hyundai.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		5,8	3	SP-III

Technical issues and repair guidelines

It’s a popular series of transmissions from Mitsubishi – Hyundai and one of the most popular Mitsubishi transmissions in repair services. Owners of cars with this type of transmissions prefer a cosmetic repair by their own forces or replacement with the used transmission.

The repair kit of gaskets and seals is ordered together with the kit of friction components. Rarely, owners decide to perform a classic reassembly and additionally order the kit of steel discs. For cars with short mileages and normal pressure state in packages, it will be enough to replace the filter (for series КМ175-177) and change ATF.

Seals are usually replaced because of fluid leakages between the transmission and the torque converter unit, which is considered to be a sign of the torque converter wear-out. Bushings and all rings are replaced in order to restore the pressure in packages. Firstly, frictions burn in Forward/Direct packages (with steel discs), then its turn for friction clutches of the package Overdrive with steel discs and the Low/Reverse package. In most cases, replacement of spare parts and friction elements is accompanied with replacement of the brake band (Kick-down). The electrical mechanism of this transmission is very reliable, and only solenoids,which reached the end of their service life, should be replaced. Before solenoids replacement, it is recommended to check the wiring integrity.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	COLT	92-94	4 SP FWD	L4 1.8L
Eagle	SUMMIT/SUMMIT WAGON	93-96	4 SP FWD	L4 1.8L
Eagle	TALON	90-94	4 SP FWD	L4 1.8L 2.0L
Hyundai	ELANTRA	92-96	4 SP FWD	L4 1.8L
Hyundai	SONATA	91-98	4 SP FWD	L4 2.0L
Mitsubishi	EXPO LRV	92-93	4 SP FWD	L4 1.8L
Mitsubishi	GALANT	89-93	4 SP FWD	L4 2.0L
Mitsubishi	MIRAGE	93-97	4 SP FWD	L4 1.8L
Mitsubishi	PRECIS	90-95	4 SP FWD	L4 1.5L
Plymouth	COLT/COLT VISTA	92-94	4 SP FWD	L4 1.8L
Plymouth	LASER	90-94	4 SP FWD	L4 1.8L 2.0L

F1C1 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The F1C1 CVT solution has been applied on FWD cars (Colt and Lancer) with engines of approx. 1.5 liters since 2000.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	145	7,8		CVT Fluid NS-1

Technical issues and repair guidelines

The transmission fluid for this CVT has unique qualities, namely, when the oil is hot it becomes "sticky", allowing the belt to stick to cones without slipping. Therefore the fluid should be kept clean and the filter should be replaced when the oil loses its transparency. The belt slippage damages the belt itself and cones (the main CVT unit).The fluid is heavily contaminated by friction elements and loads wear the belt protector that increases the possibility of the belt slipping and wearout of cones surface. Frequent change of fluid and filter significantly prolongs the resource of this transmission.

Advantages of of this CVT frequently turn out to be its porlems. The push belt of this CVT (as in JF011E Jatco) has a comparatively short resource and almost became a "spare part", especially if the driver likes accelerations without the warm-up. The repair kit of gaskets and seals is ordered for rebuilding of this transmission.

CVT components have the following problems:

Issue with the Forward drum consist in damage of the stop ring, rapid wear-out of the Forward frictions leading to contamination of even fresh ATF. The problem reveals itself in the failure of moving forward. It is recommended to replace not only the burnt drum, but also the belt with the filter.Cones are not subjects for repair or grinding, therefore sometimes they are replaced with used cones which have some resources.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Citroen	RVR	12	CVT FWD	L4 1.6L
Mitsubishi	COLT PLUS	04-14	CVT FWD	L4 1.5L 1.6L
Mitsubishi	DION	00-05	CVT FWD	L4 2.0L
Mitsubishi	LANCER	01-16	CVT FWD	L4 1.5L 1.6L 1.8L

How to repair this transmission (Videos)

F1C1A

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme F1C1
web	www.at-manuals.com	Scheme F1C1

TF80SC Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed front drive automatic transmission AW TF80SC (AF40-6) has been available on the market since 2003 as more expensive alternative of the 4-speed AW50-40 and the 5-speed AW55-50 for 2-... 4-liter cars: Ford (as AF40-6), Mazda (as AW6A-EL), Volvo, SAAB, Opel, Fiat and all "French" automakers Peugeot-Citroen-Renault (as AM6).

The family of AW TF80SC transmissions has two different sub-modification, for two classes of engines: "middle class" (up to 2.0 liters)- AF40-6\TF80SC and AF21\TF81SC - "heavy duty" (2.0 - 4.0liters) and has the torque capacity of up to 450 Nm.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/AWD	450	7	3,8	Type T-IV

Technical issues and repair guidelines

The torque converter intensively contaminates the ATF with dust from carbon friction lining. Almost each transmission repair includes cutting of the torque converter and replacement of the friction lining. The worn-out friction lining of the torque converter has a negative impact on the valve body. The more aggressively the driver pushes on the gas pedal, the earlier the computer switches on the slipping mode of the torque converter friction, resulting in rapid wear-out of friction plates and the necessity to rebuild the the torque converter and the valve body. This transmission is sensitive not only to contaminated oil, but also to the wear-out of teflon rings (where oil leakages may occur). The operation with worn-out spare parts leads to burning of frictions, and later to problems with solenoids and the valve body.

The whole kit of friction discs is replaced in case of burnt oil. The package С2 (4-5-6) is usually the first to burn (in some cases it may be the package 1-2-3-4 Clutch (C1)). The standard kit for reassembly includes the kit of pistons. (С2 piston+retainer, retainers С1 and С3). The kit includes the most popular pistons ordered by transmission specialists. In case of burnt ATF, it is also recommended to replace the Reverse brake band , because its friction lining is affected by burnt ATF. The problem of frictions burning are usually related to the wear-out of teflon rings.

The pump bushing turns out to be the most vulnerable part in the TF80 transmission, in case of the torque converter parts wearout. Problems may also occur in the differential (in AWD Mazda CX7, CX9). The problem lies in the spline failure. This issue is caused by the ECU settings, allowing overloading.

Generally, the TF-80SC transmission is extremely reliable and successful 6-speed unit, which causes less problems in comparison with its predecessors TF60SN and AW55-50. It may be considered as an “invincible” solution and the most maintenance-friendly 6-speed automatic transmission.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	REGAL	12	6 SP FWD	L4 2.0L
Cadillac	BLS	06-09	6 SP FWD	L4 1.9L V6 2.8L
Cadillac	SRX	09-11	6 SP F/4WD	V6 2.8L
Opel / Vauxhall	SIGNUM	05-08	6 SP F/4WD	L4 1.9L 2.8L 3.0L
Opel / Vauxhall	VECTRA	05-09	6 SP F/4WD	L4 1.9L V6 2.8L 3.0L

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme TF80
pdf	www.at-manuals.com	Valve body valves
web	www.at-manuals.com	Solenoid application chart
pdf	Sonnax	Valve Body Layout TF80SC
pdf	Sonnax	Valve Body Layout TF81SC

A999 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 3-speed automatic transmission A999 (also referred 32 RH) was produced by Chrysler. This transmission is very similar to the A904 transmission. It is equipped with 5 direct friction discs. Both automatic transmissions A999 as well as A904 have lower 1-st and 2-nd gear ratios, which help low-capacity engines to ensure better acceleration without any losses to highway fuel efficiency.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD		8,5	4,2	Mopar ATF+3

The A999 transmission is commonly applied in XJ or YJ models with the engine capacity of 4 liters. The main difference between A999 and A904 consists in the rear band, which holds the planetary gear carrier: the band used in the 32RH transmission is more efficient. This gearbox is considered to be quite reliable, so it commonly outlives other stock components.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	PICKUP/RAM	00-02	3 SP R/4WD	V6 3.9L
Dodge	VAN/WAGON 1500-2500	95-03	3 SP RWD	V6 3.9L

How to repair this transmission (Videos)

Fixing a leaking shift shaft seal A999

Instruction manuals and useful links

Link type	Source	Description
web	advanceadapters.com	999 (32RH) TORQUEFLITE
pdf	parker.com	Scheme 32RH

RE5R05A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic gearbox RE5R05A with the longitudinal positioning was used since 2000 on all powerful RWD models of Nissan as well as on Infinity with engine capacities 2.5 -6 lit.

There are a lot of various sub-versions of the RE5RO5A solution for various torque and various types of cars, which are distinct in filters, friction components, steel discs, hard parts, and valve body. All sub-versions are founded on very fail-safe construction of RWD Nissan 4-speed automatic gearboxes, which were modified with the Overdrive planetary gear and more intellectual electronic control.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD		10,5	4,2-5	Nissan Matic-J

Technical issues and repair guidelines

Typical major repairs of this transmission involve the torque converter (TC) repair, reassembly, cleaning and change of friction elements, oil and filter, and repair kit of gaskets and seals. The main repoair issue of this transmission is caused by aggressive accelerations leading to fast wear-out of the TC locking unit, resulting in wear-out of channels and valves of the valve body. Consequently, the pressure shortage takes place in different packs depending on the computer settings provided by the automaker and driving style of the car owner. The brake band is also considered to be a spare part in this gear shifting unit. On powerful and heavy vehicles, the brake band may distort the drum. This part is commonly replaced during major repairs, when the car comes to the repair service after travelling 200 thousand kilometers or gets for repair with burnt fluid, burnt frictions and steel discs.

The unpredictability of vulnerabilities of this transmission is attributed to the point that this smart system was adjusted for many various cars. The wear-out of channels of the valve body and solenoids takes place in distinct areas for different models resulting in the oil pressure loss in various areas of the gearbox. The abovementioned issue results in rapid wear-out of frictions. In Nissan Pathfinder, Infinity etc, the valve body failure is specified by the following caption "Check Engine". It is one of three typical problems with the valve body and sensors. The other two problems are breakdown of solenoids and wear-out of valve body channels.

It is advisable to change fluid in this transmission more frequently, not waiting before it becomes opaque. When performing the fluid change on a timely basis, the valve body may operate properly even after 200 thousand kilometers and the overhaul may be delayed until 300 thousand kilometers. The valve body rebuilding is performed in rare cases. More frequently, this component is cleaned or changed by the new one. Issues of the valve body may be divided into mechanical (wear-out) and electrical – breakdown of sensors, wiring, solenoids, circuit boards of the valve body.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Gonow	AOXUAN G5	10-16	5 SP RWD	L4 2.4L
GreatWall	HOVER H5	10-14	5 SP R/4WD	L4 2.0L
GreatWall	HOVER H5/H7	12-13	5 SP RWD	L4 2.0L 2.5L
Haval	HOVER H5	14-16	5 SP R/4WD	L4 2.0L
Hyundai	GENESIS COUPE	08-12	5 SP RWD	L4 2.0L
Hyundai	GENESIS COUPE	08-16	5 SP RWD	L4 2.0L
Hyundai	H350	15-16	5 SP RWD	L4 2.5L
Hyundai	PORTER	12-16	5 SP RWD	L4 2.5L
Hyundai	SOLATI	15-16	5 SP RWD	L4 2.5L
Hyundai	STAREX	07-16	5 SP RWD	L4 2.5L
KIA	BONGO TRUCK	12-16	5 SP RWD	L4 2.5L
KIA	BORREGO	09-10	5 SP R/4WD	V6 3.8L
KIA	MOHAVE	07-16	5 SP R/4WD	V6 3.8L
KIA	SORENTO	02-12	5 SP R/4WD	L4 2.5L V6 3.3L 3.5L 3.8L

How to repair this transmission (Videos)

RE5RO5A Teardown Inspection

P1757 Front Brake Solenoid Circuit

RE5R05A - TCC Shudder

RE5RO5A Part 1

RE5RO5A Part 2

RE5RO5A Part 3

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual RE5R05A
web	www.at-manuals.com	Scheme RE5R05A
pdf	Sonnax	Valve Body Layout RE5R05A
web	Sonnax	Measure the TCC Plunger Valve to Avoid RE5R05A Pressure Problems
web	Sonnax	Converter SHUDDER After a Radiator Cooler Failure Repair
web	Sonnax	RE5R05A Facts and Observations

A860E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed transmission Aisin А860Е was designed in 2005 for trucks Hino Dutro (Toyota Dyna) 300 and hit the Japanese market in 2006. However, the mass production of this “invincible” unit was started in 2009.

This transmission transmits the torque up to 420 Nm from diesel engine with the capacity 4 liters. This transmission is the main competitor of the Allison 3000 transmission.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD	420	12		Toyota T-IV

Technical issues and repair guidelines

This transmission is very reliable as all RWD Aisin transmissions. The repair of this transmission in most cases includes oil and filter replacement.The transmission reassembly requires the repair kit of gaskets and seals with valve body spare parts, which are ordered because of sealing rings, which wear out earlier than all other spare parts and gaskets.

The electrical part of this transmission is maximally unified: the valve body has 3 simple and invincible On-Off solenoids, 3 interchangeable linear solenoids ( А, C, D solenoids according to the manual), responsible for an ideal gear shifting and a linear solenoid (B). Solenoids usually are quite reliable, but in case of any issues related to the valve body, solenoids are considered the main cause of these problems. Aisin valve bodies produced after 2009 are notable for enhanced durability and are almost not ordered for replacement.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hino	DUTRO	99-16	6 SP RWD	L4 4.0L
Toyota	COASTER	97-16	6 SP RWD	L4 4.0L

A540E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission А540E produced by Aisin Warner has been used since 1989 on AWD and FWD 2- 3 liter Toyota Camry, RAV4, Sienna and Lexus ES250 and ES300. In terms of design, this transmission is the part of А140 - А240 series with interchangeable parts, but it can transmit a higher torque. There are several sub-modifications of this transmission.

The most significant design changes were introduced in 1994 for А541E used with 3-liter engines, this gearbox differs in friction components of the 2-brake package andadditional 4-th solenoid of the torque converter lockup in the valve body. Tested design, simple electrical components and most importantly control settings that made it impossible to load components of this transmission to maximum torques – all these conditions ensured high reliability parameters of the A541 unit and durability of this transmission.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD/4WD	280	8	3	Toyota Type T-IV

Technical issues and repair guidelines

There is no much information on the repair of this transmission, because it operates for a long time without any problems, therefore it is hard to point out any soft spots in А540-541 transmission units. It has been reported that the first released gearboxes (A540H before 1991) had some issues with the reverse gear. The most common reason for appearance of these transmissions in repair services is related to the change of oil and replacement of filter (for А541Е Camry V6).

The А540E unit usually gets in repair service with worn-out torque converter frictions causing clogging of the valve body and solenoids, resulting in the pressure shortage in packages (frictions and discs get burnt) and short supply of the pump lubrication (bushing and seal burn and leak).Problems of А540E (А541E, 540H) are commonly related to ill-timed preventive measures for the torque converter, and have nothing to do with durability of this robust transmission capable of covering one million kilometers (standard for Toyota) with just few replacements of the torque converter lockup and ATF change.

Usually at the early stages of wear-out of old Toyota cars owners restrict repair actions to the low-cost repair-cleaning of the valve body with replacement of seals and the pump bushing.The repair process obviously includes the pan gasket replacement. When taking more serious approach to the overhaul of used transmission, it is common to replace all gaskets and seals kit. After the overhaul, this transmission can operate until the end of the car service life.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LEXUS	ES	90-01	4 SP FWD	V6 2.5L 3.0L
Toyota	CAMRY	88-93	4 SP FWD	V6 2.5L 3.0L
Toyota	CAMRY GRACIA	00-01	4 SP FWD	L4 2.0L 2.2L V6 2.5L
Toyota	RAV4	96-00	4 SP F/4WD	L4 2.0L
Toyota	SIENNA	98-03	4 SP FWD	V6 3.0L

How to repair this transmission (Videos)

A540E teardown

Toyota Avalon Transmission A541E

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Manual A540E
pdf	www.at-manuals.com	Scheme A540E

A440F Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Automatic transmissions A440 and A442 are very reliable units. Repair services for these transmissions resemble the repair of manual transmissions.These 4-speed automatic transmissions were installed on "invincible" and powerful Land Cruiser with the engine 4 liters since 1985 up till 1995 (440F), and then from 1993 the A442F modification made this transmission family of Aisin Warner very popular as well as А340 (AW30-40LE).In 1998 electrical components and the valve body of the A442F. It is a low-maintenance transmission in regard to ATF status, but the fluid cleanness should be taken into consideration.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/4WD	420	15	6	Dexron III, VI

Technical issues and repair guidelines

The А440 - 442 units are notable for their reliability and even 20-year old transmissions basically require only replacement of friction filters and repair kits.The torque converter with worn-out lockup clutch is frequently repaired in this transmission. After 10-12 years of service all gaskets, seals and rings get worn and fragile, therefore they should be replaced. The replacement of spare parts of the repair kit gives this transmission additional 3-5 years of service life. The Precision overhaul kit is used more often than Transtec overhaul kit.The first spare parts that get worn-out are teflon rings and frictions of Forward and Direct packages.

The pump cover bushing is a common component to be replaced in these “invincible” transmissions. This problem may be caused by the worn-out torque converter, overheating, clogged valve body or ageing of the transmission itself.The planetary gear Forward is the first to get out of order in old Land Cruisers. It’s a rare case when in this gearbox you get burnt drums, pump gears, valve body, torque converter, but when it happens the structure of this transmission is not to blame, except for the fact that it is allowed to heat the oil with slipping up to 150 С. It is said that after the overhaul this simple and resourceful transmission starts a new service life. This family of transmissions has a long service resource, that allows us to call this transmission “invincible” under conditions of sufficient cooling and timely fluid change.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Toyota	LAND CRUISER	88-92	4 SP 4WD	V6 4.0L 4.2L

How to repair this transmission (Videos)

A442F Automatic Transmission Service

Landcruiser Transmission

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme A440F

A24A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

First of all Japanese engineers pay much attention to the reliability rate when manufacturing automatic transmissions. Reliability became an important factor when Japanese specialists decided to produce 4-speed automatic transmission M4TA (released in 1997) without planetary gears. The advantage of this solution is considered to be improved reliability. But it the same time it should be noted, that such transmissions have a massive size, therefore it complicates the process of repair. The automatic transmission M4TA was installed on Honda Civic, Odyssey, Prelude, Accord, crossover CRV. The maximum engine capacity allowed for this transmission equals to 2,4 liters.

Honda CIVIC; 92-95 4 SP FWD L4 1.5/1.6L; Honda A24A

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		5,9	2,7	Honda Z-1

Technical issues and repair guidelines

As it has been mentioned above the automatic transmission M4TA is notable for its enhanced reliability. The car owner only needs to regularly change the oil with filter elements. It is required to use high-quality transmission oil, that preserves bushings and friction clutches from wear-out.

In most cases it is required to perform the overhaul after travelling 300.000 kilometers or more. At the same time it should be noted, that improper operation of the transmission and aggressive driving behavior may lead to frequent malfunctions resulting in the overhaul after running 100.000 kilometers and even earlier. Therefore it is necessary to point out, that this transmission is mainly intended for operation in urban environment.

In the list the most frequent malfunctions we should point out problems with seals and rubber-covered gaskets. Rubber covered linings may get out of order rapidly leading to oil leakages. In this case it is required to replace rubber covered gaskets and seals. Implementation of these repair procedures may be troublesome because of the transmission dimensions. The pan disassembly is a complicated procedure and should be performed in the service facility. In the process of overhaul specialists perform the valve body state check, replacement of friction clutches and drums. In some specific cases it is required to replace burnt clutch. Generally this transmission makes a good impression, distinguished by reliability and repairability.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Honda	CIVIC	92-95	4 SP FWD	L4 1.5L 1.6L

How to repair this transmission (Videos)

S24A/A24A/M24A

Honda Civic Teardown Inspection

Instruction manuals and useful links

Link type	Source	Description
0	www.at-manuals.com	Scheme

A240 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

This family of 4-speed automatic gearboxes 240 (А240 - 245, А246Е etc.) has been used since 1985 on famous and reliable Corolla as well as on Corona, RAV4 models with engine capacity up to 2 liters. The А246 unit without any significant updates is still used on Corolla and RAV4.This line of gearboxes also includes А140-series intended for higher torque. The A140E unit had been used since 1983 up to 2004 on more powerful Camry (with the engine capacity from 2 liters) assembled in the USA and Japan.

At the same time, a bit more sophisticated and highly-priced version named А540 was produced for even more powerful engines of Camry and Lexus. The modern line generation of this transmission family ( A245E/ A246E /247Е) hit the market in 2003. The А247Е model has a bit more improved hard parts aimed to endure higher torque from 2-liter engines. In 2003, the valve body was modified one more time: the unit received a linear solenoid of main pressure, the filter with a pan, as well as a significant improvement of the software part.

Despite the fact that this gearbox is not complicated and has a low price, the family of these 4-speed gearboxes is not so popular as more "sophisticated" Aisin analogs of "U" series. The market rivals of this gearbox are not German ZF4HP16 - 4HP18, competing with U240, but Jatco's 4-speed RE4F03 - RE4F04 units.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	186	7,2	3,1	Toyota Type T-IV

Technical issues and repair guidelines

Overhauls in repair services commonly consist of repair of the torque converter, valve body, gearbox reassembly and replacement of spare parts and burnt friction components. Usually during the overhaul specialists have to deal with old gearboxes having the lockup mechanism worn to the glue layer, which reaches other frictions. Therefore, it is advisable to replace the whole set of friction discs during reassembly procedure. For problem-free exploitation of this gearbox, it is required to change fluid and (after 8-10 years) replace the filter on a timely basis. It is also recommended to replace the filter, if the gearbox has been used with burnt fluid or worn friction in the torque converter.

The most sensitive issue for the A240 unit is the wear-out of the lockup friction in the torque converter (TC) clutch which makes solenoids and valve body dirty.These gearboxes can cover substantial distances without any repair, but after 200 thousand kilometers it is advisable to monitor possible leakages of the pump seal and timely perform repair of the TC unit. Seals (of pump, axle shaft, cuffs etc.) start leaking because of a long exploitation period or due to wear-out of the TC lockup and resulting vibrations. The transmission shaft seal is replaced together with other seals. When delaying with replacement of seals, then it may be needed to change the rotating pump bushing.Solenoids are quite durable as well as, the brake band. The design of these elements hasn’t been changed since 1985.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Daihatsu	APPLAUSE	0	4 SP F/4WD	L4 1.6L
Pontiac	VIBE	03-09	4 SP F/4WD	L4 1.8L
Pontiac	VIBE	04-07	4 SP F/4WD	L4 1.8L

How to repair this transmission (Videos)

A140E Solenoid Test

Teardown - Rebuild A140E

Tranny Sub-Assemblies A140E

Transmission Assembly A140E

Transmission Assembly A140E p.2

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme A140
pdf	www.at-manuals.com	Repair manual A140
pdf	www.at-manuals.com	Scheme A240
pdf	www.at-manuals.com	Repair manual A240

6R140 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

6R140 is one of the most reliable automatic transmissions created by Ford. Repair specialists of the company introduced a durable single-piece bell shaped construction for 6R140. This construction is notable for its stiffness. The gearbox has a deep first gear with a double overdrive.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	AWD		16,5	8,5	Mercon LV

Technical issues and repair guidelines

The Lepelletier toothed gearing solves the problem of matching gearboxes’ gear sets and clutches. So this gearbox employs just 5-clutch sets to get 6 forward gears. 6R140 is reinforced by the usage of a metallic powder carrier within the compounded gear set. The carrier consists of four compressed elements, which are forced together to form a hard composition. 6R140 has a new torque converter which contributes to longer operability and a high-powered turbine damping mechanism introduced to smooth the force from the engine.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	F-250	11-16	6 SP RWD	V8 6.2L
Ford	F-250/350 SUPER DUTY	10-16	6 SP R/4WD	V8 6.2L 6.7L
Ford	F-350/450/550 CAB CHASSIS	16	6 SP R/4WD	V10 6.8L V8 6.2L 6.7L

How to repair this transmission (Videos)

Transmission Disassembly and Identification

6R80 Teardown

Fluid and Filter Replacement

6R140W Intro ATRA

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout 6R140
pdf	Sonnax	Vacuum test 6R140

6F50 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The family of 6-speed automatic transmissions Ford 6F50 / 6F55 was designed jointly with GM for FWD and AWD vehicles Ford with engines capacity up to 3.5 liters. This transmission is used for powerful Explorer and Taurus with gasoline engines (3.5 liters) and diesel engines (2.5 liters) and intended for a maximum torque equal to 380 Nm. In two years more advanced modification 6F55 was released for the torque equal to 407 Nm and engine V6 (3.5 liters). The list of cars with transmissions of this family is constantly growing. Over the last years these transmissions found application on Mazda Tribute and CX-9, Mercury Mariner, Milan etc. 6F50 is also classified as 6T70 by GM.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/AWD	380	9,5	5	Mercon LV

Technical issues and repair guidelines

The 6T70 unit is considered to be more problematic in comparison with Ford modification. 6T70 had many problems related to electrics and transmission components. In 2012 several significant updates were introduced with addition of wavelike rings in packs and performance optimization of solenoids plate and the valve body.

The 6F50 / 6F55 (GM 6T70 / 6T75) transmissions found application on rare American vehicles. For rare overhauls specialists usually order the filter with the pan gasket, which should be replaced with ATF after 50-80 thousand kilometers.It should be taken into account that for this class of automatic transmissions it is crucial to monitor the ATF state (DEXRON-VI - GM or Mercon 5 - Ford) and its temperature. The quantity of fluid required for full change is approx. equal to 9.5 liters. It is advisable to repair the torque converter and clean the valve body when having problems with shifting and operation of the valve body with solenoids.

A quick failure of the torque converter caused by contaminated fluid may be considered as a soft spot of this transmission. This problem leads to oil starvation or increased pressure and cranking of bushings. The valve body is repaired by replacement of worn valves with enlarged valves from Sonnax. Problems of this transmission often start with the wear-out of rings and bushings. Contaminated fluid from the torque converter speeds up the wear-out of these seals and damages solenoids.This transmission rarely gets in repair services as well as cars with this good automatic transmission produced by Ford.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	EDGE	06-16	6 SP F/4WD	V6 3.5L 3.7L
Ford	EXPLORER	10-16	6 SP F/4WD	V6 3.5L 3.7L
Ford	FLEX	08-16	6 SP F/4WD	V6 3.5L
Ford	FUSION	09-12	6 SP F/4WD	V6 3.5L
Ford	TAURUS	07-16	6 SP F/4WD	V6 2.7L 3.5L 3.7L
Lincoln	MKS	08-16	6 SP F/4WD	V6 3.7L
Lincoln	MKT	09-16	6 SP F/4WD	V6 3.7L
Lincoln	MKX	06-14	6 SP F/4WD	V6 3.7L
Lincoln	MKZ	12-16	6 SP F/4WD	V6 3.7L
Mercury	SABLE	08-09	6 SP F/4WD	V6 3.5L

How to repair this transmission (Videos)

TSS and OSS sensor removal and installation

6F50 overheating problem

Drivers Side Axle Seal Replacement

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme 6t70
pdf	Sonnax	Valve Body Layout 6F50
pdf	Sonnax	Valve Body Layout 01JGM 6T70 (Gen. 1), 6T75 (Gen. 1)
pdf	Sonnax	Vacuum test GM 6T70 (GEN. 1), 6T75 (GEN. 1)
pdf	Sonnax	Vacuum test 6F50, 6F55
pdf	Sonnax	How Small Changes Led to the New Form & Function of Gen. 2 6T70/75 Valve Bodies
pdf	Sonnax	GM Gen. 1 6T70/75/80 \| Ford 6F50/55 Concerns & Repair Techniques

6F35 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission 6F35 (6F30) is a collaborative investment project of Ford with GM released in 2002. With regard to transmission components 6F35 is practically a complete analog of the GM 6T40- 6T45 transmission, details for manufacturing of these transmissions are unified to the fullest extent and differ only in electrical elements, filters, and pans. This transmission has been installed since 2008 on popular American FWD and AWD vehicles of Ford (Kuga, Focus, Escape, Fusion...) and Mazda (Tribute) with the engine from 1.6 up to 3 liters. There are two different modifications of the 6F35 – with engines less than 2.5 liters and 3 liters engine. The design of the 6F35 is based on the flagship model 6F50 /6F55= 6T70 /6T75, constructed on modular principle of maximum standardization and interchangeability of blocks.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/AWD	350	8,5	4,8	Valvoline MaxLife Multi-Vehicle ATF / Mercon LV/ Motorcraft XT-10-QLVC

Technical issues and repair guidelines

In most cases repair procedures f6F35 transmission consist of oil (DEXRON®VI or original XT-10-QLV) change and filter replacement. This transmission is very sensitive to the ATF level. It has no ATF level gauge and its levellevel is tested in compliance with the overflow stopper. As all 6-speed transmissions, the 6F35 (6F30) is sensitive to loads when the ATF is cold.

Many complaints have surfaced about erratic gear shifting, with gears harsh engagement and sometimes even slipping out of reverse or forward gear. The problem is most pronounced when the car is on the road, and happens when the transmission is stuck in one gear. It has been found that moving components within the transmission can create more friction, leading to issues requiring repair.

The 6F35 Transmission in Ford Fusion and Ford Perform cars is particularly prone to overheating issues. It is important to ensure that the control unit settings are adjusted appropriately, and also that the driver’s driving style is suitable for the vehicle. A dogged cooling system with less than optimal capacity has been found to depend on overall performance, so it may be worth removing Automatic Transmission Fluid (ATF) from the car.

This is one of the most common problems with 6F35 conventional 5-speeds transmission issues, and can be easily rectified by a keen driver. The 6F35 transmission offers better fuel economy than its conventional 5-speeds counterparts and covers their 6f35 cars in Ford, covering over 50,000 miles in some cases. It is also good for long run drivers as it provides a greater gear span and optimal speed load combinations with much better optimal combinations.

The 6F35 Transmission has a number of design flaws which can cause problems for drivers. One of the most common issues is that the transmission tends to drag engine rpm when shifting gears, especially when towing heavy loads. Another started problem is reluctance or little reluctance when starting off from a complete stop, especially on mountain roads or when driving in stop and go traffic on a Saturday afternoon. Towing is usually the most common cause of transmission problems as it runs the engine harder than normal and can cause significant wear on components over time. The 6F35 Transmission has been known to be reliable but certain design flaws can cause problems if not addressed properly.

One common issue is that the computer commanded 1st gear and 5th gear command will switch when read drive is commanded by the computer. This can be easily fixed by changing the range switch to read range switch and ensuring that the input speed sensor is operating properly. Another issue is when the shifter is moved, the rpm figure drops about 200 rpm from its original figure of around 2. This happens for a short time and can cause a few issues if it happens multiple times.

One of the most common 6F35 transmission problems is a failed one way clutch. This clutch can cause the wheel speed signal to be lost which will limit engine power and prevent the vehicle from moving. If this happens, it may be necessary to replace the converter. Additionally, if equipped with a problem vehicle, there may also be an issue with floor shift selector lever and display shifts. In some cases, it can even cause a push button start to not work correctly or no throttle response when starting the vehicle.

6F35 Transmission Problems And Possible Solutions can include malfunction valves, control valve, and the valve body separator plate. The malfunction can cause a compromise cooling in the heat exchanger. As a solution on transmissions, it is important to install a fluid heater in order to properly lubricate the transmission. Additionally, removing check ball is necessary to allow for proper flow of transmission fluid. It is also recommended to install a fluid cooler before any additional modifications are done. When using Mercon LV transmission fluid, it is important to note that the deleted hole must be drilled back into the valve body separator plate in order for it to pass proper flow of coolant from one side of the transmission dipstick tube over to the other side.

This external cooler bypass valve is necessary for the proper flow of coolant in order to prevent overheating and eventual transmission failure. If an experienced fluid leak is present, it can lead to a deteriorating fluid which compromises lubrication, leading to deterioration of internal components and eventually catastrophic failure of the transmission. Ford Fusion cars that are experiencing 6F35 transmission issues may be left with a failing left half shaft seal or other related issues if not addressed properly.

If you are having transmission problems, post your car in our cars section to see if others are having the same issues. Certain problems may be resolved with a simple transmission fluid flush or replacing the left half shaft seal. On our 2015 Ford Explorer, we had to completely rebuild the transmission and it was a costly endeavor. To keep track of any potential issues with your car, it is best to keep a log of when you drive your car and the mileage each time.

This can help you detect any problems with your 6F35 transmission early on. I recently had to repair my 6F35 transmission, and Ford sent me a rebuild kit to fix the inherent 6f35 problems. I took my car to the repair shop and they were able to use the kit from Ford to fix the problem. If you are not comfortable with fixing the issue yourself, I would advise you to take your vehicle into a dealership for them to look at it. They may be able to provide you with a powertrain warranty for any potential issues that may arise in the future. If this does not work, then Ford may even send your mechanic out a kit so they can use it in order to fix it up for you. However, this does not always guarantee that the problem will be fixed as some of their kits use faulty factory parts which could just postpone any inherent 6f35 problems until later down the line when they appear again.

In order to make sure that this doesn’t happen, it is a good idea to bring the car to a repair shop and have an experienced technician install the unit. The technician will also be able to use engine and transmission data as well as perform line pressure checks, hook pressure transducers, and hook cases to the mainline pressure port.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	EDGE	11-16	6 SP F/4WD	L4 2.0L
Ford	ESCAPE	08-16	6 SP F/4WD	L4 1.5L 1.6L 2.0L 2.5L
Ford	EXPLORER	11-16	6 SP F/4WD	L4 2.0L 2.3L
Ford	FOCUS	14-16	6 SP FWD	L4 1.5L
Ford	FUSION	09-16	6 SP F/4WD	L4 1.5L 1.6L 2.0L 2.3L 2.5L
Ford	GALAXY	15-16	6 SP FWD	L4 1.5L
Ford	S-MAX	13-16	6 SP FWD	L4 1.5L 2.0L
Ford	TAURUS	13-16	6 SP FWD	L3 1.5L L4 2.0L
Ford	TRANSIT CONNECT	13-16	6 SP FWD	L4 1.6L 2.5L
Lincoln	MKC	14-16	6 SP F/4WD	L4 2.0L 2.3L
Lincoln	MKZ	12-16	6 SP F/4WD	L4 2.0L
Mazda	TRIBUTE	08-11	6 SP F/4WD	L4 2.3L 2.5L V6 3.0L
Mercury	MARINER	09-10	6 SP FWD	L4 1.6L 2.0L 2.5L V6 3.0L
Mercury	MILAN	09-10	6 SP F/4WD	L4 2.5L V6 3.0L

How to repair this transmission (Videos)

6F35 Oil (Fluid) Change procedure on 2009-2012 Ford Explorer Escape Fusion

ATF Fluid Change on 2013-2019 Ford Explorer Escape Fusion

LH Axle Seal Leak Repair in 6F35 transmission

6F35 Full Rebuilding Process

Highlights and Valvebody

6F35 Teardown

6F35 Calibration Program

Solenoid Body Strategy Programming

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Vacuum test 6F35 (Gen. 1), 6F35 (Gen. 2)
web	Sonnax	Solenoid Differences Between 6F35 Gen 1. & Gen. 2
web	ATSG	6F35 Repair Manual
0	Unknown	Installation Guide for 6F35
0	Transmission Digest	6F35 Overheating Issues Solution
0	Sonar	Solving One-Way Clutch Failure on Ford 6F35 Torque Converter

68RFE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission 68RFE produced by Chrysler has been installed since 2006 on pickups Dodge RAM 2500-3500 with engine capacity of 6 liters and higher. In terms of design, this transmission is based on 45RFE and on the 5-speed 5-45RFE.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	AWD		15,7	6,5	Mopar ATF+4

Technical issues and repair guidelines

During the reassembly, specialists use the following repair kits:

-Kit of gaskets and seals or a complete kit of gaskets, seals, frictions and steel discs (Master Kit)

- Kit of pistons (5 pieces). Many details and spare parts are common with the 5-45RFE.

- The complete kit of friction components is ordered for the automatic transmission reassembly.

The valve body and the block of solenoids are the main vulnerabilities for the 5-45RFE transmission. After 100 thousand kilometers, it is required to monitor the state of these components (oil pressure, cleaning). The valve body and solenoids often reach the end of their service lifespan after 3-5 years of active exploitation, especially with the worn torque converter clutch.

There are problems with the 68RFE torque converter (overrunning clutch, friction, gaskets). It is recommended to replace spare parts in the torque converter quite early, because of problems related to American torque converters.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	PICKUP/RAM 2500-3500	09-16	6 SP R/4WD	L6 6.7L

How to repair this transmission (Videos)

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Introduction to the 68RFE
pdf	www.at-manuals.com	Scheme 68RFE
pdf	Sonnax	Valve Body Layout 68rfe
pdf	Sonnax	Vacuum test 45RFE, 545RFE, 65RFE, 66RFE, 68RFE
web	Sonnax	Solving the 6R80 Transmission Leak Mystery

5HP30 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission ZF5HP30 is one of the first 5-speed transmissions with a maximum torque. This transmission was developed for special vehicles with RWD and powerful engines with the capacity from 4.5 liters.

In terms of design, this transmission is related to 5HP24 (intended for a bit lower torque) and has some common spare parts (such as seals and solenoids) with a legendary 5HP19. Compared to 2 abovementioned transmissions, ZF5HP30 has the reserve of structural integrity. This transmission was designed to become an "invincible" unit without obvious soft spots and a high safety degree in all components.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD		13	5,5	LT -71141

Technical issues and repair guidelines

The transmission requires a planned overhaul after running well beyond 300 thousand kilometers (under the condition of normal operation and timely fluid change). The transmission reassembly is performed together with filter replacement, torque converter repair and replacement of rubber and paper gaskets. The drum (Forw/Rev. Clutch A+C) is considered to be a soft spot of this transmission (aluminum teeth get cu

All solenoids are replaced with the purpose of ensuring reliability, because their resource usually comes to an end after 7-10 years of exploitation together with wear-out of the torque converter. The worn-out torque converter clutch is the main source of premature ageing of solenoids and as a consequence – problems with pressure in packages. In general, this transmission is quite reliable with a high safety reserve on transmission elements.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Aston-Martin	DB7	00-04	5 SP RWD	V12 5.9L
BMW	5-SERIES	91-03	5 SP RWD	V8 3.5L 4.4L
BMW	7-SERIES	95-01	5 SP RWD	V8 3.5L 4.4L V12 5.4L
RollsRoyce	ARNAGE/SILVER SERAPH	00-03	5 SP R/4WD	V8 4.4L V12 5.4L

How to repair this transmission (Videos)

Oil Change Part 1

Oil Change Part 2

Valve Body disassembly

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual 5HP30
pdf	www.at-manuals.com	Spare parts catalog 5HP30

5HP18 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed ZF5HP18 transmission is related to 4-speed 4НР14 and 4HP22 units. It had been installed on RWD BMW of 3-rd,5-th and 7-th series with 2-3 liter engines since 1991 up to 1999. The ZF5HP18 unit is a predecessor of famous ZF 5HP19 for a bit less powerful engines (310 Nm in comparison with 325 Nm in 5HP19). This well-designed gear shifting solution with high reserve on transmission components, which served as a prototype of the ZF 5HP19 solution.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD		10,5	5-5,5	LT -71141

Technical issues and repair guidelines

This transmission endures exploitation with contaminated fluid, fluid shortage, and operation without a warm-up. This transmission will fully serve the service life, if you monitor the ATF quality and timely replace the metal-plastic filter with a felt membrane. This transmission can operate with different types of oil (works well with oils like Dexron III).Too rapid ATF contamination is a signal of gaskets wear-out and trigged by it risk of oil starvation on fiction components.

To perform a typical overhaul with reassembly of worn-out gaskets and rings repair specialists usually order the Overhaul kit for this transmission.The most vivid soft spot of the 5HP18 unit is the clutch package F – the first one to get out of order because of ATF shortage and burnt frictions.The cause of this problem is related to design of the drum F bushing with a sealing, which become the source of leakages leading to oil starvation and bushing cranking.If the abovementioned problem stays neglected, then the clutch drum F with a piston gets burnt together with frictions. This problem is solved by the bushing replacement with the bearing.

The oil pump is one more typical part to be worn-out in “old” transmission hard parts under the condition of long-term exploitation with worn-out torque converter and pump bushing.The valve body is a long-running and maintainable unit.

The pressure solenoid (EPC) is a main part to be replaced or repaired among electrical components.Shifting solenoids are similar to solenoids used in the 4HP18 unit and they serve for a long period of time. EPC solenoids are the first to get out of order, then comes the turn of the TCC solenoid. In all other respects, the resource of this transmission is compatible with the resource of the whole car.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
BMW	3-SERIES	0	5 SP RWD	L6 2.5L 2.8L
BMW	5-SERIES	93-95	5 SP RWD	V8 3.0L
BMW	7-SERIES	0	5 SP RWD	L6 2.8L
BMW	M3	95-98	5 SP RWD	L6 3.0L 3.2L

How to repair this transmission (Videos)

Complete Tear Down

5HP18 Clutch Rebuild

Valve Body DIY

Valve Body DIY Part 2

G Clutch & Spring Damage

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual 5HP18
web	www.at-manuals.com	Scheme 5HP18

5EAT Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed RWD transmission 5EAT was designed in 2003 by Jatco on commission from Subaru for popular models Tribeca, Impreza, Outback, Legacy on a constructive basis of Jatco JR507E , reengineered for the engine room of Subaru.

Since 2005, the 5EAT unit has been operating on LEGACY model equipped with engines having the capacity from 2 to 3.6 liters. Later this transmission was paired with 3-liter engines Н6 on American models of Tribeca and Outback. The Impreza model for the Japanese market was also equipped with this transmission.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	AWD	350	10	5,6	Subaru ATF HP

Technical issues and repair guidelines

This transmission allows accelerating as DSG by means of the torque converter lock-up slipping, leading to rapid fluid contamination and resulting in damage of the friction lock-up. Consequently solenoids wear out and the valve body gets clogged.Therefore, manufacturers of automatic transmissions assume that it is better to change the fluid with filter after covering 80 thousand kilometers (depending on the driving style) and change it the next time when oil transparency is not good enough. After 120-150 thousand kilometers, it is necessary to check for the presence of metal grit in the pan.

Oil change and first overhauls usually require order of the plastic filter with felt "accordion" connection.Specialists install the external main filter sequentially to metal coarse mesh filter. The filter is located outside of the transmission and access to it is maximally facilitated. The main filter helps to keep the oil clean and reduces the wear of the friction components and aging of solenoids. These measures are recommended for all old transmissions, which have a regular filter with a metal mesh.The repair kit of gaskets and seals/Overhaul kit is usually ordered with the kit of friction components.

There are two types of solenoids which are usually get replaced: solenoid in the Direct package (this solenoid operates more intensively than others) and solenoid of the second type with a cover plate, and the problem is specified by the computer error (The problem may lie in the spooling burn-out resulting in improper gear shifting or wear-out of the valve mechanical part.). The list of typical problems in the 5ЕАТ unit also includes solenoids and the speed sensor overheating and clogging with dirt and metal chips from the torque converter.

The list of soft spots for this transmission also include:

-Pump with bushing and seal.

- Shaft with a sun gear of an interaxle planetary gear for vehicles with engine capacity over 3-liters.

The design of the 5ЕАТ unit is similar to the construction of Jatco’s RE5R05. Many spare parts in these transmission units are interchangeable. But the valve body and solenoids are different.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Subaru	EXIGA	08-16	5 SP F/4WD	H4 2.0L
Subaru	IMPREZA	11-13	5 SP 4WD	H4 2.0L 2.5L
Subaru	LEGACY	03-14	5 SP 4WD	H4 2.5L H6 3.6L
Subaru	OUTBACK	09-14	5 SP 4WD	H6 3.6L
Subaru	TRIBECA	06-14	5 SP 4WD	H6 3.0L 3.6L

How to repair this transmission (Videos)

Subaru 5eat Valve Body

Instruction manuals and useful links

Link type	Source	Description
pdf	subarufanclub.cz	Technical data 5EAT
pdf	atsg.us	5EAT VALVE BODY ASSEMBLY
pdf	transmissionpartsus.com	Scheme 5EAT

4T80E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 4T80E was designed in 1993 together with 4.6 liter engine V8 Northstar for FWD Cadillac models. In 2004, this heavy and high-priced transmission was significantly updated and installed with the same engine on Buicks and Oldsmobiles.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	450	14,2	6,6	Dexron VI

Technical issues and repair guidelines

The owner of this rare transmission usually order only a 3-component filter. The overhaul generally consists in the valve body cleaning, the torque converter repair and gaskets replacement.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	LUCERNE	05-11	4 SP FWD	V8 4.6L
Cadillac	CONCOURS/SEVILLE	95	4 SP FWD	V8 4.6L
Cadillac	DEVILLE/SEVILLE/CONCOURS	96-05	4 SP FWD	V8 4.6L
Cadillac	DTS	05-11	4 SP FWD	V8 4.6L
Cadillac	ELDORADO	95-02	4 SP FWD	V8 4.6L
Cadillac	LIVERY/HEARSE/LIMO	97-01	4 SP FWD	V8 4.6L
Oldsmobile	AURORA	95-03	4 SP F/4WD	V8 4.0L

How to repair this transmission (Videos)

4T80E Teardown

4T80 transmision from cadillac 2003

4t80e trans side case bearing

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Sensors 4T80
pdf	www.at-manuals.com	Converter Update for GM’s 4T80E
web	www.at-manuals.com	Scheme 4T80e

4HP18 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission ZF 4HP18 (4HP18FLA Audi) was on SAAB 9000 (4HP18Q), Rover, Peugeout, Citroen. In 1989 this transmission was updated. Later, several more modifications were released. Presently, this transmission is mainly installed on FWD Audi 100 with engine capacity from 2.0 up to 3.0. Later this transmission was updated for AWD Audi 100 and Audi Quattro. ZF 4HP18 had been used on the abovementioned cars until 1994. This transmission competed with the legendary 097-01N transmission from Audi.The design of the 4HP18 unit became the foundation for the 5-speed 5HP18 and later for extremely popular 5HP19.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD/AWD		9	4	LT 71141

Technical issues and repair guidelines

The majority of 4HP18 repair cases accounts for the transmission modification for Audi. But about the fifth part of all repair operations is related to Saab, Alfa 164, Lancia, Citroen, which have a round filter.

This transmission successfully operates with different types of fluid (LT 71141 as well as with Dexron 2 or 3). Synthetic oil is more efficient, therefore analogs of Dexton III are often used when performing complete fluid change.It is required to keep the fluid clean by means of regular and partial ATF change to reach the mileage of 300-400 thousand kilometers before the first overhaul. It is prohibited to use fluids of different colors, when performing partial oil change.

The repair kit of gaskets and seals is usually ordered when performing reassembly of this transmission. Overhaul and Precision kits are also quite popular. All compression rings and rubber elements of all burnt packages also get replaced. It is common to replace frictions of Forward and 3-4 packs.

This transmission is handed in for repair (that happens quite rare) with the complaint, typical for old transmissions: burnt clutch packages and brake bands. Common parts for replacement in this transmission are pump bushing and turbine shaft bushing. Vibrations turn down the compression ring located on support of the pump.The “cosmetic” overhaul of this transmission with worn-out torque converter sometimes is limited to the pump repair and its bushing with the pump seal replacement. Minor repair operations of electrical parts (decayed isolation and contacts) are performed without transmission removal by owners themselves.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	MONACO	90-92	4 SP FWD	V6 3.0L
Eagle	PREMIER	90-92	4 SP FWD	V6 3.0L

How to repair this transmission (Videos)

ZF4 HP18 Transmission: Part 1

ZF4 HP18 transmission. Part 2

How to replace ZF4-HP18 governor seals

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Application chart
web	www.at-manuals.com	Scheme

09G Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 09G (TF60-SN - according to Aisin Co classification) is the first 6-speed transmission which has been used since 2003 for virtually all FWD cars of Volkswagen and Audi family (A3, A4 and TT) with engine capacity from 1.4 up to 2.0 liters (Mini Cooper, Skoda Fabia, Polo)

The 09G is designed for torque up to 280 Nm.This solution is the successor of 5-speed AW55-50. It competes with the German transmission ZF 6HP19-/21 and considered to be more durable and relatively cheap in repair.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD	280	7	4	G 052 025 A2

Technical issues and repair guidelines

The 09K and 09M sub-modifications were released after testing and upgrade of the 09G transmission. They were used together with engines with the capacity equal up to 3.5 liters (TF-62SN -61SN, Passat, Superb, Transporter). Many other modifications of this transmission, which differ mainly in electric components and the valve body construction, can be encountered in the repair shops. Peculiarities of the TF60SN transmission are typical for most of 6-speed transmissions and are associated with fast ATF contamination by the friction lining of the torque converter which operates with slipping of the lockup clutch, and when the engine operates under unusually high temperature. The torque converter is rebuilt during each overhaul.

Typical repair procedures for the 09G (TF-61SN \TF-60SN) transmission

Typical overhaul of the 09G transmission involves reassembly and replacement of following spare parts:

A set of 4 problematic pistons consisting of a piston / retainer pair for a problematic package К2 (С2) and retainers of clutches K1 and K3 is almost always changed together with seals and gaskets (overhaul kit). It is recommended to replace friction clutches together when the К2 package burns out completely and the rest of friction linings are stained with burnt ATF
Abnormal operation of the TF60-SN valve body often manifests itself in problems with 4-5-6 speeds. Error codes - P0734, P0735 or P0729 signal that solenoids and valves of the valve body are worn / clogged. The solenoids are rebushed with the help of the Bushings Repair Kit.
The transmission pump is the next stage in the repair process. The axle deformation, surface damage and bushing cranking are caused by an uneven wear out of friction lining and related thereto vibrations. The tool kit of bushings (5 pieces) also gets replaced. The most deformed bushings are: bushings of sun gear, rear cover, pump, and package К3 (С3).

The typical malfunction can be described as follows:

1-st stage. The torque converter friction gets actuated with slippage starting from the 3-rd gear, without waiting for the levelling of the transmission and engine shaft RPM. The friction element gets damaged and contaminates ATF with hard and sticky powder.

2-nd stage. Plungers and valves get blocked and give less oil pressure to one of the packages, and as a result, worn parts have leakages, oil overflows, critical decrease of pressure in the clutch packs.

One of the most complicated cases is the wearout of the valve body and/or one of its irreplaceable components. Then it is required to change the entire valve body. Another reason the valve body failure is the replacement of solenoids which exhausted their performance potential. Preliminary, it is required to check the wiring and electrics contacts. It is rare that problems are caused by the shaft speed sensors ISS and OSS, they are cleaned and the ATF is washed off. The replacement of pump and semi-axle seals is also performed quite frequently.

The pump bushing (46.9x43.9x14.8) is replaced, if the wear-out reaches 0.10 mm. First of all, friction components and clutch steel discs K2 4-5-6 (C2) are examined for wear. Clearances in clutch packages affect the quality of switching and hard parts wear-out. It is required to change the Piston К2 (C2) and the retainer. The retainer K1 is also replaced quite frequently. The cause of this problem is solved by replacing the repair clutch of the rear cover. It is more rarely that you have to replace spare parts of the K3 package. In many cases, the clutch drum wear-out leads to some kicks (impact) while shifting gears. The factory clearance (gap) is 1.4 mm. When the clearance (gap) increases up to 1.8 mm, then kicks become noticeable. Such friction components are replaced to stop the wearout chain reaction.

Problems with the rear planetary gear are mainly explained by slipping of insufficiently lubricated bushings. The torque converter is one of the typical problems for 6-speed automatic transmissions. It works with a wide “slippage mode”. The pressure for blocking is provided not by simple electric valve, but by the PWM solenoid. This mode of operation increases the car efficiency, but enormously speeds up the process of wear-out for the torque converter friction lining.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	TT	03-06	6 SP F/4WD	L4 1.8L
Volkswagen	TOURAN	03-06	6 SP FWD	L4 1.6L 1.9L

How to repair this transmission (Videos)

09G Transmission Repair - Part-1

09G Transmission Repair Part-2

TF60SN solenoids fix recondition repair upgrade shift kit

Instruction manuals and useful links

Link type	Source	Description
pdf	media.cylex.com	6-speed automatic gearbox 09G Service
pdf	www.atra.com	Disassemble the Solenoids 09G
pdf	www.evosoft.dk	Design and Function Self-Study Program 09G
web	www.at-manuals.com	Solenoid/clutch application chart 09G
pdf	Sonnax	Valve Body Layout TF-60SN
pdf	Sonnax	Vacuum test AW TF-60SN, BMW 6F21WA, VW/AUDI 09G, 09K, 09M

JF506E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission 09A \ 09B (according to Jatco - JF506E classification) was designed in 1999 by Jatco for the European market of FWD cars with engine up to 3.8l. The first budget version of this 5-speed automatic transmission is used in the cars as a reliable and unpretentious alternative to expensive the AW55-50 from Aisin and ZF 5HP19-24.

After several modifications, this transmission has been actively used in Nissan – as RE5F01A and in Mazda as JA5A-EL. Most of all, this transmission is found under the German name 09A \ 09B in VW, Audi and under the name JF506E - in the English Jaguar and Land Rover. American Ford tried to use this transmission for European Mondeo and Galaxy (as 5F31J). The Japanese had been installing this transmission until recently at American assembly plants of Nissan (Altima, Quest) and Mitsubishi (Eclipse, Galant). JF506E is mainly installed on English Jaguar X, Rover, Freelander, less often – on German Golf, Bora, Jetta and even less often on Portugese SEAT Alhambra and AUDI А3.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	FWD	350	9	5	G 052 990

Technical issues and repair guidelines

The 09A\09B/JF506E filter with metal mesh is replaced during the transmission reassembly. The planned overhaul of older JF506E lies in replacement of worn-out rings and gaskets which are frequently exposed to leakages. The overhaul includes the assembly and replacement of the whole friction components kit. Kicks, pushes, and slipping in this transmission are considered to be the symptom of solenoids and valve body malfunction.

One of the reason for valve body malfunction is the damage (by contaminated ATF) of the channel and valve (TCС Pressure Regulator Valve) controlling torque converter blocking . Then goes a chain reaction related to fast ATF contamination by the torque converter clutch, and dirt starts damaging other channels and solenoid-operated valves. The whole solenoid kit (9 pcs) is usually replaced in the process of transmissions (which covered more than 200-300 tonne-kilometre) overhaul. Common spare parts for cosmetic repair are: pump seal and pump bush, which is identical for RE4F03A. The filter helps to preserve ATF clean and reduces friction units wear-out.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Volkswagen	BORA	00-05	5 SP F/4WD	L4 1.8L 1.9L L5 2.3L
Volkswagen	GOLF/GTI	00-07	5 SP FWD	L4 1.8L 1.9L L5 2.3L
Volkswagen	JETTA	02-08	5 SP F/4WD	L4 1.8L 1.9L DIESEL V6 2.8L
Volkswagen	SHARAN	00-10	5 SP F/4WD	L4 1.8L 1.9L V6 2.8L

How to repair this transmission (Videos)

09A Transmission - Teardown Inspection

Freelander Transmission

solenoid replacement

transmission N92 solenoid bolt fix

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Technical supplement JF506E
pdf	www.at-manuals.com	TransTec Manual JF506E
web	www.at-manuals.com	Solenoid application chart JF506E
pdf	drive.google.com	Repair manual Update Handbook ATSG JF506e

010 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Since 1975 this 3-speed automatic transmission VAG 010 (later in 1983, it was used as a prototype for the automatic transmissions 087 and 089) has been successfully operating on many FWD models of Volkswagen (CABRIOLET, GOLF, JETTA) and Audi (80, 100, 200, ... and 4000S) with engines from 1.6 to 2.2 liters and on all Audi models starting from simple Audi 80 up to Audi 5000S. One more rare modification of this transmission for RWD vehicles - "090" (VANAGON) was released in 1978.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD		6	3	Dexron III

Technical issues and repair guidelines

The most popular kit of spare parts for maintenance of this “invincible” transmission, which often comes to the repair shop with half million kilometers of mileage usually consists of:

- Kit of friction components

- Kit of gaskets and seals (Overhaul Kit)

- Full kit of spare parts, which includes all gaskets, seals, frictions and steel discs (MasterKit). Sometimes, repair specialists order a separate kit of steel discs.There is some difference between repair kits of gaskets and seals for Audi 087 and 089 models.

As for the replacement frequency, then come the following spare parts:

- pump and axle seals (included in the repair kit), which are replaced with a full kit of bushings, their wear-out causes vibrations (which damage seals) and oil pressure in packages gets lost (that leads to friction linings burning);

- Rubber-covered pistons with friction clutches of packages Forward or Direct;

- Brake band (Direct, High/ Reverse) is replaced when it is completely worn;

- Rebuilding of the torque converter with replacement of spare parts.

This automatic transmission is very simple and reliable, which is used by many specialists as a guidebook for learning trasnmission repair methods.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Volkswagen	CABRIOLET	85-92	3 SP FWD	L4 1.8L
Volkswagen	GOLF	85-92	3 SP FWD	L4 1.8L 2.0L
Volkswagen	JETTA	80-92	3 SP FWD	L4 1.6L 1.7L 1.8L

How to repair this transmission (Videos)

BUILDING A VW TRANSMISSION

010 AUTOMOTIVE AUTOMATIC TRANSMISSIONS – LAYOUT and OPERATION

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Type 010 3-Speed Diagnosis & Overhaul
pdf	www.at-manuals.com	Transmission breakdown illustration 010
pdf	sympatico.ca	010 troubleshooting guide
pdf	thesamba.com	Repair manual 010 transmission

BAXA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4- speed automatic transmissions BAXA had been installed in Honda Accord since 1998 until 2002 and in Acura with the engine capacity 2.3 liters since 1998 until 1999. The list of construction peculiarities of BAXA transmission includes: 6 solenoids, 2 pressure sensors, and lack of overrun clutches. The design concept of solenoids helps to manage the shift overlap for upshifts and downshifts.

Honda Accord; 98-00; L4 2.3L; Honda BAXA; ATF Capacity/Change: 6.4/6.1 2.9/2.7

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		6,1	2,7	Honda Z-1

Technical issues and repair guidelines

The list of commonly replaced spare parts in this transmission includes two typical problems: wear-out of clutches of the 2-nd gear and damage of bearings. With worn-out clutches the car can operate for quite a long time, but the damage of bearings leads to non-operability of all transmission units. Bearing chips easily get through filters and penetrate aluminum transmission parts, plastic ring gaskets, and literally “eat” transmission components. The differential bearing is damaged in most cases, and sometimes needle bearings on shafts.

Wear-out of the 2-nd gear has the following symptoms:

1. Slipping when switching on the 2-nd gear

2. Jolt when stopping the car

3. Experiencing a jolt when shifting from mode D to 2 (when the car is stopped with started engine and depressed brake pedal).

The wear-out of bearings is identified with the help of following signs:

1. The sound of transmission disappears when shifting gear in “Park” or “N” mode. This symptom indicates damage of needle bearings in shafts.

2. Slap noise in chassis when running over high spots on the road, a large clearance of the transmission driven shaft, oil leakages from seals of driving gears.

1. Regular change of ATF and installation of additional radiator cooling system can really help in extending the service life of BAXA transmission.

2. When first signs of the transmission malfunction are detected, it is required to dissemble transmission and replace clutches, ring gaskets, and bearings.

How to repair this transmission (Videos)

Part 1 Disassembly BAXA

Part 2 Disassembly BAXA

Part 3 Disassembly BAXA

BAXA Automatic Transmission Overhaul Part 1 Teardown

Overhaul Part 2 Reassembly

AXOD Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The history of 4-speed FWD AXOD / AXOD-E / AX4S transmission started in 1986 when Crown Victoria was very popular with the engine 4.6 liters and Ford came up with the idea to produce a new bestseller for vehicles of lower class – Ford Taurusс with the engine capacity equal to 3.0 liters.

This transmission can be considered as a model emulated by the whole world of automatic transmissions. The transmission identification is specified according to the shape of the oil pan and gaskets. The gasket was covered with rubber in 1999 for the AX4S, but the pan shape was the same.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	250	12,2	6,6	Mercon V

Technical issues and repair guidelines

This family of automatic transmissions didn’t have a strong reputation among transmission experts. The transmission had a lot of problems with shifting gears 1-2, required frequent ATF changes, and had a short resource before and after the overhaul.

It is assumed that design solutions on the torque converter for this transmission are not good enough. All updates intended for improving the comfort of driving and its cost efficiency led to the following consequences: the transmission started operating under harsh conditions in terms of ATF temperature and its contaminanation.

The overhaul usually consists of transmission reassembly with the repair kit of gaskets and seals "Overhaul kit". “Old” vehicles (and vehicles which get in repair services with burnt oil) require replacement of brake bands O.D. and Rear (for old models). Due to the oil pressure losses in the line, problems occur in the shaft and its bushings. Spare parts of packs Direct and Forward usually get burnt because of high rate of operation. The main problem is related to the transmission design. And it is recommended to solve this problem by installing additional transmission radiator and each year change the ATF and replace the filter.

How to repair this transmission (Videos)

AX4S Overheating

transmission problem

AX4S 4F50N No Forward Gears

Instruction manuals and useful links

Link type	Source	Description
pdf	drive.google.com	AXODE (AX4S) UPDATE HANDBOOK ATSG

ATX Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

ATX is a 3-speed automatic transmission manufactured by Ford within the period from 1981 until 1994. It was Ford's 1-st automatic gearbox designed for FWD and cross-mounted engine. The structural design of this transmission is not complicated, but very reliable. This gearbox has a lockup torque converter, but no overdrive gear.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD		5,6	3,2	Type H ATF /Dexron III/Mercon ATF

Technical issues and repair guidelines

ATX was mainly installed in Ford Taurus and Ford Escort models. This fully hydraulic transmission is rarely met in repair services. However, owners of ATX may have problems with gear shifting if the engine is not warmed up. But transmission repair specialists say that the reason of this issue lies in wear-out of plastic gears, which can be replaced without dismounting and disassembly of the transmission.

How to repair this transmission (Videos)

Ford Escort ATX Transmission Fluid Change

A618 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The family of 4-speed automatic transmissions "TorqueFlite" - A518 / A618, has been mainly installed on the rear-wheel drive trucks and vans produced by Dodge and Jeep since 1990. The A518 was modified to 46RH (retainer hydraulic) and later to 46RE (retainer electronic), while A618 was updated to 47RE and 48RE. The A618 transmission is considered to be a heavier-duty modification of A518. The driving torque of the A618 transmission is equal to 610 Nm.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	610	13,4	4,8	Mopar ATF+4

The design of the A518/A618 and 46RH / 46RE / 47RH / 47RE / 48RE transmissions is based on the same principle. All differences and modifications consist in the increased number of gears and addition of the torque converter and the block of solenoids.

Typical problems

Transmissions of this family were used by car manufacturers for three decades thanks to their easy maintenance and resistance to wear. Not complicated assembly of these transmissions simplifies their repair process. Early transmissions of this family rarely require any repair. The problem of spare parts replacement occurs in cars equipped with transmissions, which have solenoids and the valve body. These transmission components get out of order when the car mileage reaches 100 thousand kilometers. Such breakdowns result in expansive repair services, because damaged components should be replaced.

The most problematic areas in A518/A618:

- Central Support

- Retained (Governor) is usually rebuilt

- Direct Drum – exhausts its resource, but more often this component burns out because of a long-time operation with insufficient linear pressure

- Reverse Drum

- Frictional wheel-hub. Direct.

- The set of solenoids and sensors

Other seals, bushings, springs and bearings fail to function occasionally, due to peculiarities of the driving style and operation.

How to repair this transmission (Videos)

47rh tear down

Remanufactured Transmission

48RE Transmission Teardown Inspection

Dodge 47RE

CUMMINS 47RE TRANSMISSION REBUILD

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout 48RE
web	Sonnax	Dodge 48RE Hydraulic Features Revealed

A40D Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The legendary family of automatic transmissions А40D (А42, А43, А44, А45, A46) was developed by Aisin Warner and belongs to Toyota Group. They have been used since 1985 as a 3-speed transmission named as 03-55(А40), and since 1979 as a 4-speed transmission for RWD cars with the engine capacity from 1.6 up to 3 liters. The 4-speed gearbox has D letter in its name and an additional clutch "Overdrive" in the 4-speed in the design.This gearbox is mainly used in right-hand drive cars (Hiace, Liteace etc.) and in other Toyota RWD cars in Asia. The modification with some other valve body AW03-70 .../72 or AW371, AW372 was produced for other markets. This modification was installed on Suzuki, Mitsubishi, etc. The most popular models of this family in repair services A44DE, 46DE \F (Previa), A42DE, 43DE were updated and released in 2000. This transmission is an example of a standard structural design, which was widely used by ZF in 4HP22 and by American Ford in its A4LD. The design of almost all rear-driven gearboxes ensures uniform wear-out of all units and solid safety coefficient of gearbox components, therefore these gearboxes easily travel 500 thousand kilometers. Earlier the repair process mainly involved transmission replacement.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	230	6,3	4	Toyota T-IV

Technical issues and repair guidelines

Typical issues of the А40 transmission are mainly caused by the the unit's ageing:

- Damaged torque converter lockup clutch. The damage of the lockup frequently causes heavy vibrations, resulting in the seal damage, then leading to issues with the pump liner and the pump itself.

- Worn-out friction components in Direct- Forward and Reverse packs. Old cars usually require replacement of these frictions.

- Rubber elements become hard with time and overheating causes the wear of rings, leading to pressure supply deficiency in packages and burning of friction components.

Overhauls mainly include the transmission reassembly and cleaning procedures accompanied by spare parts replacement – namely, worn-out brake blocks, frictions and gaskets with seals. All friction components are usually replaced during the overhaul of transmissions in cars with high mileage and burnt oil.The second most commonly replaced component in this transmission is the Low reverse clutch. Major repairs of hard parts mainly take place when the pump bushing (and leaking seal) gets damaged by the torque converter lockup clutch.

How to repair this transmission (Videos)

A40 Series Transmission Parts Identification

A40 Series Transmission - Powerflow

A40 hydraulic overview

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual A43D
pdf	www.at-manuals.com	Repair manual A46DE
pdf	www.at-manuals.com	Scheme A40D
web	www.at-manuals.com	Clutch application A40
pdf	mitsubishi-motors	Repair manual V4AW2-3

A130 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In terms of design, the 3-speed automatic transmission A131L with hydraulic control belongs to the family of FWD transmissions (А140 -\240-\540). Almost all hardware and spare parts are interchangeable.

This automatic gearbox is a very rare “guest” in repair shops. This is partly thanks to the fact that this transmission is maintenance friendly, simple, trouble-free in operation and its service life is much longer than the lifespan of the most reliable car. Usually this transmission is installed on American Corollas.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD	150	6,3	2,4	Dexron VI

Technical issues and repair guidelines

Simple and robust design of the A130 unit with two “invincible” planetary gears and without solenoids gives no reason for visits to repair services.The overhaul of this gearbox takes place after impressive mileages and frequently involves the torque converter repair, replacement of seals and gaskets, and less frequently replacement of worn-out friction components and even less often – brake bands.

Car owners prefer to change the filter (possible to use a А140 filter) than cleaning it, therefore statistics related to selling of spare parts for this transmission is unimpressive. A new filter with a narrow slot scoop produced in 1990 was supposed to force auto owners to change filters.The most common spare parts that wear out in these gearboxes are the following: seals, gaskets, rubber elements that become hard, weakening spring, damaged Direct and Forward friction elements, worn-out brake band.

How to repair this transmission (Videos)

Service A131L

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme

6T40E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The family of 6-speed automatic gearboxes of GM 6T30E, 6T40E, 6T45E "Hydra-Matic" is a state-of-the-art range of FWD gearboxes used on Buick and Chevrolet vehicles from 1.4 to 3.2 lit. The 6T45E found application on FWD and AWD vehicles.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD	250	8,2	4	Dexron VI

Technical issues and repair guidelines

These gearboxes can operate properly with spare parts of different quality. Standard repair kits of gaskets and seals produced by ATOC often ordered for repair of these gearboxes.In case of ATF overheating it is often required to change all pistons because the rubber gets hard under the influence of the temperature. The set of pistons consists of 5 pieces.

The transmission fluid for these gearboxes should be changed every 40-80 thousand kilometers and checked for opacity every visit to repair services taking into account short service life of solenoids and torque converters (TC) with slippages. In the course of each overhaul, TC is reassembled and the lock-up clutch is replaced, because its wear-out reduces the resource of solenoids.Leaking seal of the TC unit is a sign of possible issues with the pump bushing, which gets damaged by vibrations and wear-out of the TC lock-up.

The construction of this gearbox is conceptually the same with ZF of 6HP series and problems in these gearboxes are caused by the same factors:vibrations which damage bushings. Vibrations lead to situations when ATF leaks through worn-out bushings.This is one more present-day gearbox in which it is important to examine the quality and temperature of ATF. In situation of any apprehensions related to contaminated ATF – change the fluid for protecting the valve body. It is also recommended to keep a wary eye on symptoms of the pressure loss in the line after a long-term operation as well as check and clean the valve body with solenoids. The TC unit repair with replacement of friction discs is required in the situation of rapid ATF pollution and issues with the valve body (especially with the mileage higher than 130-150 thousand kilometers). Overloading with high torques and aggressive accelerations also may have a bad impact on this gearbox.

On the top of everything else, experts recommend to install additional transmission radiator for the whole 6Т range of transmissions. Cars with this transmission manufactured over the last years are adjusted in more cautious way and stop drivers from using the car with neglect to this good 6-speed gearbox, which is capable to compete with Jatco CVTs in terms of comfort.

How to repair this transmission (Videos)

Removing the bellhousing to install seals and a filter

6T40 Teardown

6T40 Series, no reverse

6T40 Valvebody

6T75-E Transmission - No Reverse

6T70 Teardown

6T70 Valvebody

6T75 TCM REPAIR

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Scheme 6t40
pdf	www.at-manuals.com	Repair manual valve body 6t40
web	www.at-manuals.com	Solenoid identification 6t40
web	www.at-manuals.com	Stall test
pdf	Sonnax	Valve Body Layout 6T30 & 6T40 (Gen. 2), 6T45 (Gen. 2), 6T50 (Gen. 2)
pdf	Sonnax	Valve Body Layout GM Gen. 1 6T40, 6T45, 6T50
pdf	Sonnax	Vacuum Test Guide 6T45 (Gen. 2), 6T50 (Gen. 2), 6T30, 6T40 (Gen. 2)
pdf	Sonnax	Vacuum test valvebody 1st GEN. 6T40, 6T45, 6T50

4HP22 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission ZF 4HP22 was designed in the early 1980s for 2-3 liter diesel (rear-driven) car models. It has a "classic" engineering structure, ensuring not only high robustness, but also even wear-out of parts without obvious soft spots. The 4HP22 - 24 unit was used by all European automakers of high-priced and reliable cars: Audi, BMW, Jaguar etc. In terms of design, this transmission is similar to famous A4LD from Ford and A40-series from Toyota. The 4HP24 unit found application in 4WD models.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	400	9,3	4	LT 71141

Technical issues and repair guidelines

The difference between 4HP22 and 4HP24 modifications lies in frictions and steel discs in packages. The modification with the valve body (type Е9) and 4 solenoids is the most common in repair, while earlier series with 5-solenoids in the valve body are considered to be a rarity.The ZF 4HP24 unit is a fail-safe and massive transmission, constructed with the help of high-quality materials, ensuring enhanced safety margin.

Repair procedures

Friction components of the Forward package are the first to get burnt because of intensive operation. The percentage of hard parts replacement and seals (separately) is quite low only in the overhaul kit (repair kit). It is common to replace worn-out pump housing bushing (covers – 17 mm), and less frequently bushings (13 mm) with the pump gasket and pump seal in the 4HP22/24 unit suffering from oil starvation. Land Rover’s oil pump gets out of service early because of contaminated fluid and long-term operation with a faulty torque converter. It is required to perform the torque converter repair together with the abovementioned procedure.The improper operation of clogged or worn-out solenoids and valve body is named as the main reason of oil starvation causing burning of the package Forward.

The replacement of solenoids is a scheduled procedure for old cars using this transmission. The problem of a dirty valve body is usually explained by worn-out locking clutch of the torque converter. If there are some delays with gears shifting, kicks or slippage in ZF 4HP22 with mileages above 200 thousand kilometers, then it signals that springs and solenoids cannot handle the dirt from frictions falling on valves. The minor overhaul prolongs the resource of this transmission for many years. It is suggested that the average resource of ZF4HP22 (4HP24) before the overhaul can reach up to 300 thousand kilometers, but it depends on the driving style “aggressiveness”.

How to repair this transmission (Videos)

Service & Valve Body Recondition

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme

BGHA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

This family of 5-speed automatic transmissions Honda includes several sub-groups. A typical order for reassembly of 5-speed automatic transmission in old cars includes the following:

- Repair kit of gaskets and seals
-Kit of friction components
- Filter
- Electrical parts and Low block

Spare parts for the 5-speed automatic transmission designed by Honda should be selected according to the VIN-code.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	AWD		7,9	3,3	Honda Z-1

Technical issues and repair guidelines

In many cases, the Low Hub one-way clutch gets out of order because of overloadings. It gets wedged and the sun gear breaks. High torque from 3-liter engine damages the rear drum of the 3-rd package (3rd Drum). The spring breaks, that causes damage to the entire unit. Specialists also replace piston, a thin spring holder, retaining ring. In addition a powerful engine damages rear bearings.EPC line pressure solenoids (which operate very intensively) get out of order because of ageing and overheating. Another soft spot of the valve body is the jar of accumulators, rubbing shafts with teflon rings that leads to the pressure loss.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Acura	MDX	01-02	5 SP 4WD	V6 3.5L

How to repair this transmission (Videos)

BGHA Transmission - Teardown Inspection

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout BVGA Honda/Acura 4/5 Speed
web	Sonnax	Keeping Cool While Investigating Mystery Honda Overheat
pdf	Sonnax	Honda/Acura 4/5 Speed Identification Guide
web	Sonnax	Overheated Honda Converters/740 Codes

M4VA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The first Honda CVT transmission named as M4VA (Multimatic) was designed in 1995 for Civic with engine 1.6 liters and had been installed on American models of Honda until 2000. In 2000 this CVT was slightly updated and renamed as MLYA, but after a short time a new modification under the name SLYA was released and installed not only on American Civic but also on Honda City. The modification SLYA didn’t have typical problems of the predecessor and this CVT had been produced from 2002 until 2005 for Civic with the engine 1.7 liters. To this day SLYA is installed on 1.5 liter Honda Fit.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	AWD		6,8	4,1	Honda Genuine CVT (VTF)

Technical issues and repair guidelines

The belt is the main spare part which specifies the lifespan of this gearbox. In terms of design, this gearbox is very similar to the RE0F06A equipped with a push belt. The chain gets strained and and side teeth wear down. Timely detected problems with the belt allow saving surfaces of shafts and only to replace the belt. As with all pushing belts, it is crucial to set the right direction of the belt during the assembly operation, otherwise the owner will soon have to order a new CVT.

The overhaul of this popular and rare (in repair) CVT is usually accompanied with order of the following spare parts:

- Filter cassette

- Filter in the pan

- Pan gasket

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Honda	AIRWAVE	05-11	CVT F/4WD	L4 1.5L
Honda	CIVIC HX	96-00	CVT FWD	L4 1.6L
Honda	FIT	09-12	CVT FWD	L4 1.3L

JF613E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed transmission JF613E with transverse mounting was produced by Jatco in 2006 for FWD Mitsubishi cars with engine capacity from L4 2.0 to V6 3.5 liters. According to Jatco, this heavy-duty transmission can transmit the torque up to 330Nm. The JF613E unit competes with Aisin's TF80SC, but Jatco transmission is considered to be less complex and cheaper, and when taking into account parameters of reliability and endurance with American 6T45 and Korean A6MF1.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/4WD	330	7,6	5,5	DiaQueen ATF J3

Technical issues and repair guidelines

Transmission fluid is changed after travelling 50-60 thousand kilometers without waiting for scheduled replacement of worn-out spare parts (rings and bushings).The torque converter is repaired in the course of the overhaul. The overhaul also requires Kit of gaskets and seals, complete kit of frictions, and less often kit of steel discs.

The main source of problems for all modern 6-speed automatic transmissions is related to the valve body and solenoids.Settings of the JF613 control unit do not allow excessive loading of solenoids. This gearbox as well as Aisin's 4-speed transmissions use forced locking of the torque converter starting at the 4-th gear (that has a positive impact on the transmission durability). Thanks to this feature JF613 may be called "invincible".

“Active locking” and “auto-neutral” features implemented in JF613E are considered to be the pride of Jatco. Both options improve acceleration characteristics, fuel consumption, driving comfort, driving uphill, but at the expense of the friction lining locking wear-out in the torque converter, leading to quicker ATF contamination. Planned repair for this transmission is not complicated and it is required in case of high mileage. The repair helps to prolong service life of this transmission for a long period of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mitsubishi	DELICA D:5	12-16	6 SP 4WD	L4 2.2L
Mitsubishi	LANCER	07-16	6 SP FWD	L4 1.8L 2.0L
Mitsubishi	OUTLANDER	08-16	6 SP F/4WD	L4 2.2L 2.4L V6 3.0L
Mitsubishi	RVR	13-16	6 SP 4WD	L4 2.2L
Nissan/Datsun	MURANO	10-15	6 SP 4WD	L4 2.5L
Nissan/Datsun	PATHFINDER	14-16	6 SP 4WD	L4 2.3L V6 3.0L
Nissan/Datsun	QASHQAI / QASHQAI+2	07-13	6 SP F/4WD	L4 1.6L 2.0L
Nissan/Datsun	X-TRAIL	07-15	6 SP 4WD	L4 2.0L
Renault	ESPACE	07-16	6 SP FWD	L4 2.0L V6 3.5L
Renault	KOLEOS	08-16	6 SP F/4WD	L4 2.0L
Renault	LAGUNA	07-15	6 SP FWD	L4 2.0L V6 3.0L 3.5L
Renault	LATITUDE	10-16	6 SP FWD	L4 2.0L V6 3.0L
Renault	MEGANE	09-16	6 SP FWD	L4 2.0L
Renault	SCENIC	06-16	6 SP FWD	L4 2.0L
Samsung	QM5	07-16	6 SP F/4WD	L4 2.0L
Samsung	SM7	11-16	6 SP FWD	V6 2.5L 3.5L

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Solenoid application chart

JF011E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The RE0F10A (JF011E) transmission is a popular Jatco model of 2005 for FWD vehicles with engine capacity from 1.6 up to 2.5 l. This transmission is assumed to be a marvel among CVTs. JF011E is a genuine leader of CVTs with record-breaking productions. It is very popular thanks to its durability, comfort, easy maintenance in combination with a low price. This CVT unit is very maintenance-friendly. Well-timed rebuilding procedures with replacement of spare parts add 3-4 years of service life before the next overhaul.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD/AWD	7,4	4,5		CVT Fluid NS-2

Technical issues and repair guidelines

In the process of major repairs, it is required to change the friction clutch of the torque converter lock-up. CVTs produced after 2007 turn out to be reliable (for CVTs) under the condition of proper usage and operates for 150-200 thousand kilometers with a low number of visits to repair services. It is one of the most reliable CVTs around the globe. Common spare parts usually include belt, step-motor (stepper), shaft bearings.

Spare parts of the first priority include:

- seals of the pump, axle shafts (left and right)

- Pan gasket

The step-motor ("stepping" motor of the gear ratio adjustment). The electric drive regulates the space between cones and gear ratio of CVT. Early breakdown of the step-motor is related to the overheating or CVT resource exhaustion. This issue comes from the RE0F06A and it is typical for JF011.

One of the most common reasons for getting into repair services for this transmission is related to the oil pressure shortage connected with improper working of worn-out valve of the high-pressure pump. In many cases, it is required to replace 4 bearings of input and output shafts. The issue is caused by overheating and critical wear-out of the belt, forcing solenoids to apply maximum effort on pressing the belt to cones. One of the most popular spare parts for JF011 units is a metal push belt RE0F010А (Bosch). Timely replaced belt preserves the surface of cones.

Solenoids with exhausted resource are also common for replacement. Some solenoids are interchangeable with other Jatco CVTs. But there also can be some differences with CVTs of Mitsubishi and Dodge. Another typical problem for the RE0F10A (RE0F06A) unit is related to the depress valve. This problem leads to oil starvation in CVT units. In the pump, the valve is replaced by the new one of a larger size. The service life of this CVT and the car itself is estimated by wear-out of cones. Surfaces of cones are considered to be the most important resource of CVT. The price of new cones with replacement service sometimes is higher than the price of an “old” car.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Citroen	C-CROSSER	09-12	CVT F/4WD	L4 2.0L 2.4L
Citroen	RVR	12	CVT FWD	L4 1.8L
Dodge	CALIBER	06-12	CVT F/4WD	L4 2.0L 2.4L
Dongfeng	S15	11	CVT FWD	L4 2.0L
Mitsubishi	CX	10-11	CVT FWD	L4 1.8L 2.0L
Peugeot	4007	09-12	CVT F/4WD	L4 2.0L 2.4L
Suzuki	SX4	11-13	CVT FWD	L4 2.0L

How to repair this transmission (Videos)

Transmission RE0F10A JF011E teardown

RE0F10A JF011E F1CJA CVT2M Disassembly Teardown Analysis

CVT TRANSMISSION BALL TO PIN CONVERSION PART 1

CVT TRANSMISSION BALL TO PIN CONVERSION PART 2

TRANSMISSION BALL TO PIN CONVERSION PART 3

JF011E Valve Body Inspection

RE0F10A JF011E Fault P0868 & Removal for Overhaul

Coolant Contamination

Jatco CVT

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	An Overview and a Look at Power Flow
pdf	www.at-manuals.com	Electronic and Computer Control Systems
web	www.at-manuals.com	Transmission RE0F10A (JF011E) Stall Test
pdf	Sonnax	Valve Body Layout JF011E (RE0F10A)
web	Sonnax	Chasing Bearing Noise in the JF011E CVT
pdf	aamcoftp.com	Manual JF011e

FNR5 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission FNR5 (FS5A-EL - Mazda, 5F27E - Ford) was designed in 2004 on the basis of the 4-speed automatic transmission 4F27E. This unit has several new elements, some upgrades in the valve body and settings of the control block for better acceleration characteristics, fuel saving and increase of smoothness in gear shifting. Since 2005, this transmission has been installed on FWD Mazda 6 (3-8) and Ford Fusion with the engine capacity from 2.0 up to 2.5 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	FWD	250	8	5	ATF-FZ

Technical issues and repair guidelines

A typical soft spot of this automatic transmission family lies in the combination Drum Reverse + Rear cover. Aggressive driving style leads to the Overdrive clutch burning. Another typical problem of the 4F27E transmission occurs in Mazda cars, namely, wear-out of the servo mechanism seat of the band Overdrive. This problem is caused by vibrations from operation of the worn-out drum brake band. This chain of malfunctions includes different minor problems like wearout of teflon rings located between this drum and the support of the cover, which are replaced during each overhaul even if these components have no indications of damage.

Valve bodies of this transmission for Mazda and Ford are different. The valve body for Mazda has two solenoids of the main pressure EPC (А and В). The most common problem of all present-day automatic transmissions is related to contaminated ATF clogging the valve body, that in chain order leads oil shortage in packages and burning of friction elements. Frictions in this transmission may serve quite reliably together with other spare parts and solenoids for 200 thousand kilometers and even more, under the condition of well-timed ATF change, filter replacement, and avoidance of frequent forced accelerations. The valve body requires standard cleaning and replacement of spare parts.

Traditionally, Mazda's torque converter quite early requires repair or replacement of worn-out friction lock -up simultaneously with cleaning of the valve body and replacement of the pressure solenoid. The lack of locking, unusually rapid contamination of ATF and leaks through the seal near the torque converter may be considered as the sign of repair necessity for the torque converter. Operation with the worn out torque converter leads to vibrations on the shaft of the oil pump and cranking of the pump bushing (at the first stage of wear). This problem also has a negative impact on the pump seal.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercury	MILAN	05-08	5 SP F/4WD	L4 2.3L

How to repair this transmission (Videos)

FNR5/4F27E Common Causes for Code P0741

FS5AEL/FNR5 Highlites

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Solenoid identification FNR5
web	www.at-manuals.com	Stall test FNR5

F5A51 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The family of front-wheel drive 5-speed automatic transmissions A5GF1, A5HF1 (F5A51) from Hyundai has been modified since 2005 on the basis of 4-speed predecessor F4A51 and installed on the range FWD and AWD vehicles of Kia (Sportage, Sorento...) and Hyundai (Sonata, Santa Fe, Opirus, Karens... ) for the entire range of engines from 2 up to 3.5 liters. Mitsubishi uses this transmission named as F5A51.0. This front drive family of transmissions is related to the rear drive V4A51. Parts are maximally unified and interchangeable.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	FWD/4WD		8,4	3,5	SP III

Technical issues and repair guidelines

With regard to clutch packages this automatic transmission is well balanced. These packages work properly during their lifespan. Problems are mainly related to wear-out of seals leading to oil shortages and problems with transmission components.The pump assembly is also replaced under the condition of a long-term operation with worn-out torque converter clutch and subsequent vibrations. Contaminated oil speeds up ageing of the pump and bushing. The pump bushing and the seal are the first to get out of order because of above mentioned problem.

Worn-out bushings are repaired and replaced quite frequently. Then the list of parts to be replaced includes the drum with a sun gear and the brake band. As far as the electrics of this transmission is concerned, speed sensors of the input and output shafts are the first to reach the end of their service lifespan. Solenoids Shift are standardized in all valve bodies. These solenoids operate properly for quite a long time, Solenoid-electric controller EPC (VFS) is the first to get out of order because of high loads.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hyundai	EQUUS	00-08	5 SP FWD	V6 3.0L 3.5L
Hyundai	GRANDEUR XG	00-05	5 SP FWD	V6 2.5L 3.0L 3.5L
Hyundai	SANTA FE	00-06	5 SP F/4WD	V6 3.5L
Hyundai	XG	01-05	5 SP FWD	V6 3.0L 3.5L
KIA	AMANTI	04-05	5 SP FWD	V6 3.5L
KIA	CARNIVAL	00-05	5 SP FWD	V6 3.5L
KIA	GRAND CARNIVAL	04-10	5 SP FWD	V6 3.5L
KIA	OPIRUS	03-05	5 SP FWD	V6 2.7L 3.0L 3.5L
KIA	SEDONA	02-05	5 SP FWD	V6 3.5L
Mitsubishi	DIAMANTE	00-01	5 SP FWD	V6 2.5L

How to repair this transmission (Videos)

F5A51 Sprag Rotation

F5A51 Transmission, No Forward, Slips in Reverse

F5A5A,F5A51, Transmission Rebuild

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout F5A5A (F5A51), A5GF1, A5HF1 (F5A51)

F4A51 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic transmission F4A51 from Mitsubishi company was developed in 1998. This transmission modification is intended for FWD and AWD vehicles with engine capacity from 1.3 up to 2,8 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD/4WD		8,5	3,5	SP III

Technical issues and repair guidelines

This 4-speed automatic transmission has two modifications. The modification F4A51 was used cars with engines capacity from 1,3 up to 1,8 liters. The modification F4A52 was used for more powerful engines. In terms of design, these transmissions are similar, but at the same time some elements in one transmission are larger than parts in the other one. This automatic transmission was installed on Japanese cars Mitsubishi Galant, Lancer and Korean cars Hyundai Serato, Santa Fe and Sonata. Subsequently, the transmission found application in different American and Chinese mid-size cars. Later this transmission was upgraded and a maximum engine torque was increased. It should be emphasized, that the F4A42 unit gained a good reputation. Thanks to simplicity of its design, this transmission is notable for reliability and durability. Its not a surprise when after running 300.000 kilometers this transmission does not require the overhaul. However, the service lifespan of this transmission also depends on operating conditions and the driving style of the car owner. This transmission is very sensitive to abrupt accelerations and is mainly intended for operation in urban areas.

In order to simplify the repair procedure of the F4A52 system, it is required to use special repair kits, which help transmission specialists to fix any malfunctions. Pump and seals are the main soft spots in this transmission. In specific cases, problems may occur in the valve body. The valve body damage usually leads to expensive and time-consuming overhauls.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chery	DONGFANGZHIZI	03-14	4 SP FWD	L4 2.0L 2.4L
Chery	DONGFANGZIHIZI	12-13	4 SP FWD	L4 1.8L
Chery	EASTAR	08-16	4 SP FWD	L4 2.4L
Chery	TIGGO	05-16	4 SP F/4WD	L4 2.0L 2.4L
Chery	TIGGO / TIGGO 3	05-13	4 SP FWD	L4 2.0L 2.4L
Chrysler	SEBRING	01-05	4 SP FWD	V6 3.0L
Dodge	STRATUS	01-05	4 SP FWD	V6 3.0L
Hyundai	GRANDEUR XG	00-05	4 SP FWD	V6 2.5L
Hyundai	SANTA FE	01-06	4 SP F/4WD	L4 2.0L
Hyundai	SANTA FE	06-12	4 SP F/4WD	V6 2.7L
Hyundai	TRAJET XG	00-07	4 SP FWD	L4 2.0L V6 2.7L
Hyundai	TUCSON	04-09	4 SP F/4WD	L4 2.0L
Hyundai	XG	01-05	4 SP FWD	V6 2.5L
Inokom	SANTA FE	12-13	4 SP F/4WD	V6 2.7L
KIA	CARENS	06-11	4 SP FWD	L4 2.0L
KIA	CARNIVAL	00-14	4 SP FWD	V6 2.5L 2.7L
KIA	LOTZE	05-10	4 SP FWD	L4 2.0L
KIA	SPORTAGE	04-10	4 SP F/4WD	L4 2.0L V6 2.7L
Mitsubishi	CHARIOT GRANDIS	00-04	4 SP FWD	V6 3.0L
Mitsubishi	DIAMANTE	97-05	4 SP FWD	V6 2.5L 3.0L 3.5L
Mitsubishi	ECLIPSE	96-05	4 SP F/4WD	V6 3.0L
Mitsubishi	GALANT	99-07	4 SP F/4WD	V6 3.0L 3.8L
Mitsubishi	LANCER	09-15	4 SP FWD	L4 1.5L 1.6L 1.8L
Zhonghua	JUNJIE	06-15	4 SP FWD	L4 2.0L
Zhonghua	ZUNCHI	02-12	4 SP FWD	L4 2.0L 2.4L

How to repair this transmission (Videos)

F4A51 Teardown Inspection

F4A51 Highlights

F4A51 Transmission Planet Failure

Pump Leak Cracked

Pump Alignment

No Forward, Slips in Reverse

F4A41 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission F4A41 / F4A42 from Mitsubishi was designed in 1997 for FWD vehicles of the middle class with engines (1.3 - 2.8 lit.). This transmission was strongly influenced by Chrysler. In terms of design, this range of transmissions is more related to А604, then to KM series. The F4A41 unit is installed with engines 1.3 - 1.8 lit., updated modification F4A42 for engines 1.6 - 2.8 lit F4A41-42 has been used since 1999 on many well-known FWD cars of middle class with engine capacity about 2 lit. The W4A42 is a rare version on the basis of FWD automatic gearbox for 4WD light motor vehicles.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		7,8	3,8	SP III

Technical issues and repair guidelines

This Mitsubishi-Hyundai family of transmissions is frequently repaired. The distinction between F4A41 and F4A42 units lies in distinct quantity of frictions in packs, and consequently clutch drums of various capacity. The transmission reassembly commonly requires the kit of gaskets and seals, filters and complete kit of frictions. In old cars which went through the oil starvation, specialists change the entire kit of bushings together with usual procedures related to cleaning and reassembly.

In terms of design, the main soft spot of the F4A41 unit is the planetary gear Overdrive, where the needle bearer gets dyed when exposed to overloading. The rear planetary gear and a crown gear also get out of order. This planetary gear was repeatedly updated. In most cases, specialists replace burnt Overdrive package, frictions with steel and bearing discs. The valve body is one of the causes for burning of packages Underdrive and 2-nd Brake. The wearout and clogging of valves and solenoids leads to fluid shortages not only in these packs, but also in the TC unit. The valve body was repeatedly updated and now has modifications with 5 and 6 solenoids.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mitsubishi	CARISMA	95-03	4 SP FWD	L4 1.6L
Mitsubishi	DINGO	00-02	4 SP FWD	L4 1.3L 1.5L 1.8L
Mitsubishi	LANCER	12-13	4 SP FWD	L4 1.5L 1.6L 2.0L
Mitsubishi	LANCER	13-16	4 SP FWD	L4 1.6L
Mitsubishi	LIBERO VAN	00-02	4 SP FWD	L4 1.5L 2.0L
Mitsubishi	MIRAGE	98-03	4 SP FWD	L4 1.5L 1.6L

How to repair this transmission (Videos)

Part 1 - Teardown

Part 2 - Valvebody Rebuild

Part 3 - Clutch Assemblies and Seals Replacement

Part 4 -Reassembly

Part 5 FINALE -Reassembly

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout F4A41, F4A42, F4A51
web	Sonnax	F4A41/42/51 2-3 Flare or Flare/Bump

F4A33 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Thsi family of automatic transmissions is not complicated and quite reliable solutions based on the KM170. Thanks to their simplicity and durability these transmissions found application even on American cars Dodge, Plymouth. The 4-speed automatic transmission F4A33-1 was designed in 1991 for FWD cars of business class with engine capacities from 2.0 up to 3 liters. In most cases, it is installed on Hyundai Sonata. Mitsubishi installs its own version of this gearbox on models 3000 GT, DIAMANTE, ECLIPSE. For AWD cars the modification of this gearbox is named as W4A32/ W4A33.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		7,5	4,5	SP III

Technical issues and repair guidelines

Overhauls of these transmissions are triggered by two main reasons: fluid leakages via the damaged pump seal and issues with gear shifting. Generally, the leaking pump seal is a sign that the torque converter (TC) has been operating with a worn-out lock-up and vibrations for a long time leading to the damage of bushings and seal. Overhauls of these transmissions are usually performed when the car reaches high mileages and consist of reassembly and repair of the TC unit and filter replacement. Specialist always perform the repair of TC, valve body reassembly in half of the cases with check and change of solenoids and wiring. It is also required to replace brake bands if the transmission operates for a long time with burnt fluid. The long-term operation with worn-out torque converter may lead to the damage of seal and pump bushing. As a result, the pump bushing may be replaced. Vibrations may have a negative impact on the pump, therefore specialists have to order a complete kit of bushings for these transmissions.

Overdrive frictions are frequently replaced. Specialist assume that the main reason is related to poor design of an old O.D. piston. In new modifications, this piston has an updated configuration. Usually Direct-Forward ffrictions wear out because they are highly loaded. Solenoids are quite reliable, but when problems occur they are mainly caused by circuits of solenoids (solution –cleaning of contacts). The design of this gearbox is similar to the KM170. After proper reassembly, these gearboxes easily operate for several years until the next overhaul.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	STEALTH	91-96	4 SP FWD	V6 3.0L
Eagle	TALON	91-98	4 SP FWD	L4 2.0L TURBO
Hyundai	SONATA	94-98	4 SP FWD	V6 3.0L
Mitsubishi	3000 GT	91-99	4 SP FWD	V6 3.0L
Mitsubishi	DIAMANTE	92-96	4 SP FWD	V6 3.0L
Mitsubishi	GALANT	94	4 SP FWD	L4 2.4L
Plymouth	LASER	91-94	4 SP FWD	L4 2.0L TURBO

How to repair this transmission (Videos)

DSM Transmission Tips- Volume 1

DSM Trans Tips Volume 2 - Pump 11 742 просмотра 53 1 ПОДЕЛИТЬСЯ

Trans Tips Volume 3

Instruction manuals and useful links

Link type	Source	Description
web	mitsipedia.info	F4A33 info
pdf	atdsm.com	AUTO TRANS OVERHAUL F4A33
pdf	at-manuals.com	Repair manual F4A33
pdf	at-manuals.com	Scheme F4A33
web	at-manuals.com	Solenoid identification F4A33

F3A Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 3-speed automatic transmission F3A was designed by Mazda for its top of the line FWD vehicle Mazda 626 in 1983, when 3-speed automatic transmissions were extremely popular.

This transmission turned out to be quite good in the ratio price\quality, and despite some vulnerabilities, after some adjustments it was used on Ford vehicles in the class up to 1.6 liters - Ford Festiva, Stylus, Aspire.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD	120	6,6	3	Dexron VI

Technical issues and repair guidelines

This transmission was also installed on Chevrolet Spectrum and Mazda started using this transmission in 1986 on the 323 model.Then GEO, Suzuki Swift, and Mercury had been using this transmission until 1995. Ford had been manufacturing a budgetary Aspire equipped with the F3A until 1997, when 3-speed automatic transmissions were ousted from the market. It’s a very rare case when the F3A transmission gets in repair services. Spare parts for repair of this transmission are only kits of gaskets and seals and kit of bushings. The open filter with a metal lath gets replaced quite rarely, in most cases it is just washed for reasons of economy.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	ASPIRE	94-97	3 SP FWD	L4 1.3L
Ford	FESTIVA	90-93	3 SP FWD	L4 1.6L
GEO	STORM	90-93	3 SP FWD	L4 1.6L 1.8L
Isuzu	STYLUS	91-93	3 SP FWD	L4 1.6L

CD4E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission CD4E has been used since 1994 on well-known FWD vehicles with engines 2.0 - 2.5 liters of Mazda such as 626, Tribute and MX6 (LA4A-EL). Ford used this transmission on the Probe, and later after some updates on Mondeo, Escape and Fiesta (named as the 4F44E according to a new Ford classification).This transmission became quite competitive according to the ratio price/quality and had been used until 2007 (was in production for 13 years).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	250	9,5	3,7	Mercon V

Technical issues and repair guidelines

Experts assume that the design of the CD4E transmission is not good enough for 3 liter vehicles and profitable for repair services. This is due to the fact that CD4E is installed on long-living and unique vehicles, and also that this transmission is repairable and after some minor repair it operates for a long time. It is considered to be an American version of the 5HP19 transmission (on BMW-Audi-VW).Each overhaul of this transmission is accompanied by replacement of the filter. The filter has a felt membrane. ATF is changed every 60 thousand kilometers. The electrical part in the CD4E is considered to be simple and reliable. In some cases, transmission specialists only have to replace worn out block of solenoids.

One of the most vulnerable and repairable components in this transmission is a double drum, (clutch basket) Forward/Direct (6 Cylinder). Friction components and steel discs of both drums get replaced in the process of the drum repair. It is recommended to check the bushing of this drum together with steel and cover plates. This bushing is the 1-st element to get worn-out and requires replacement to prevent vibrations and losses of oil pressure.

Another common problem is the pump shaft failure caused by overloads. The oil pump often gets out of order when metal pieces appear in gears. The rubber of pistons rapidly wears out because of oil starvation and overheating. The kit of bushings is commonly ordered for repair of the CD4E transmission. Worn-out bushings in this automatic transmission is the sign of oil shortages and abnormal dynamic loads. In terms of design, the Forward planetary gear is considered to be another soft spot of the CD4E transmission. This planetary gear cannot endure ultimate loads from the engine. The reason is related to the bearing failure.

Torque converters of the CD4E are quite sensitive for such engines. One of the most frequent problems is the wheel hub bushing wear-out. The problem is related to insufficient oil pressure, overloads and overheating. The torque converter preventive repair should be performed in the course of the first overhaul after travelling 130-150 thousand kilometers. One more issue characteristic to the “old” CD4E transmissions is related to wear-out of the differential “teeth”. It is advisable to check the differential condition during the overhaul and reassembly.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	CONTOUR	95-00	4 SP FWD	L4 2.0L V6 2.5L
Ford	ESCAPE	01-08	4 SP F/4WD	L4 2.0L 2.3L V6 3.0L
Ford	MONDEO	00-07	4 SP F/4WD	L4 2.0L
Ford	PROBE	94-97	4 SP FWD	L4 2.0L
Mazda	626	94-02	4 SP FWD	L4 2.0L V6 2.5L
Mazda	MX6	94-97	4 SP FWD	L4 2.0L V6 2.5L
Mazda	TRIBUTE	00-08	4 SP F/4WD	L4 2.0L 2.3L V6 3.0L
Mercury	COUGAR	99-02	4 SP FWD	L4 2.0L V6 2.5L
Mercury	MARINER	05-08	4 SP F/4WD	L4 2.3L V6 3.0L
Mercury	MYSTIQUE	95-00	4 SP FWD	L4 2.0L V6 2.5L

How to repair this transmission (Videos)

Teardown Inspection

CD4E Teardown Inspection

Rebuild Part 1 - Transmission Repair

Rebuild Part 2 - Transmission Repair

Rebuild Part 3 - Transmission Repair

CD4E Quick Tip

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme CD4E
web	www.at-manuals.com	Solenoid identification CD4E, LA4A-EL
web	www.at-manuals.com	Application chart CD4E, LA4A-EL
pdf	drive.google.com	Repair manual CD4E ATSG

BMXA Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Honda transmissions differ completely from the rest of automatic transmissions, because Honda does not use planetary gears. Honda transmissions are not complex in terms of design, have larger dimensions and as a result considered to be more robust. But automatic transmissions produced by Honda also have some vulnerabilities related to electronic gear shifting control: friction discs, solenoids, and the valve body.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		6	2,7	Honda Z-1

Technical issues and repair guidelines

The most well-known range of 4-speed 3-shaft transmissions M4TA - Honda (CR-V) with engines from 2 to 2.4 liters. Automatic transmissions Honda are notable for their simplicity and reliability. Because of this, many car owners neglect basic maintenance services such as ATF quality control and timely replacement of the filter. Subsequently it results in clogging of valves in the valve body and solenoids, oil starvation and rapid wear-out of sealing rings, frictions and bushings. 300-400 thousand kilometers is considered to be a standard mileage before the first overhaul for these Honda transmissions.

Repair procedures

The torque converter (TC) is the first component to be repaired in Honda automatic transmissions. A major repair with reassembly starts with change of transmission fluid and replacement of a metal filter. The main external filter is usually installed by specialists on old transmissions.The repair of this family of transmissions with the filter is performed with the help of ordered repair kit of gaskets and seals with friction elements and steel discs. Friction elements are frequently replaced separately and steel discs as a full kit. Masterkit is the fullest repair kit of friction elements and steel discs with kit of gaskets.

Honda friction components usually operate for a long time, but after exhausting an enormous resource of frictions (above 300 thousand kilometers) or when these elements are soaked with burnt oil, then the change of all frictions would be the best option.Worn-out switching solenoids of linear pressure and the clutch lock-up solenoid are commonly replaced during repair procedures. The design of solenoids includes anodized plate element, which is likely to wear. This component is changed after running over 200 thousand kilometers.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Honda	JAZZ	08-12	4 SP FWD	L4 1.5L
Honda	STREAM	02-06	4 SP F/4WD	L4 1.7L

How to repair this transmission (Videos)

Honda Bmxa Teardown

BMXA, Teardown Inspection

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	TransTec Manual
pdf	www.at-manuals.com	Scheme
pdf	drive.google.com	Transtec BMXA manual

DP0 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The French automaker PSA (Peugeot Citroen Association) in collaboration with Renault launched the mass-production of the 4-speed automatic transmission DP0 (also named as AL4) in 1999. The automatic transmission AL4 is intended for a FWD vehicles with engines from 1,4 up to 2 liters. The automatic transmission AL4-DP0 is a unique and successful solution of French engineers. The design of this transmission is very simple and well-balanced according to the principle «nothing extra».

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	210	8	4	LT 71141

Technical issues and repair guidelines

The DP0 unit has a heat exchanger for oil cooling. All transmissions with the heat exchanger operate at a temperature close to critical. In summer time, the DP0 regularly overheats and has some problems with the electrical components, namely with the valve body. It is a constructive peculiarity of many automatic transmissions with the heat exchanger. After running 80 thousand kilometers its up to the auto owner to preserve this transmission from overheating. Friction components contaminate ATF, the dirt settles in the heat exchanger (which also operates as a filter) and as a result after critical contamination of the heat exchanger the oil does not have time to cool in case of the hot weather. Therefore, the valve body (and solenoids) start operating improperly. The more contaminated becomes the fluid, the higher the operating temperature and the lower efficiency of the valve body.

The resource of this transmission before the overhaul (under the condition of careful and proper usage) may reach 150-200 thousand kilometers after well-timed repair procedures with reassembly and replacement of spare parts. After these procedures the transmsision resource may be prolonged up to 500 thousand kilometers.

Soft spots of PD0

EPC and TCC solenoids are the most frequently replaced components of the DP0 transmission. Worn bushings are also often replaced by transmission specialists. The wear-out of bushings leads to the following chain reaction: bushings start leaking, packages do not have enough oil and the computer forces the ЕРС solenoid to open the channel to the full cross section, the pump operates under maximum load and the EPC solenoid rapidly wears. The operation with fluid shortage has a bad impact on friction components of the corresponding package. The valve body is a typical area for repair. The valve body is very sensitive to overheating and contaminated ATF. Overheating changes the metal plate geometry, valves wedge and springs become overloaded until they break down.

Oil losses through worn-out joints lead to the pressure drop in the line, slipping and burning of friction components. The wear-out of one-sided friction discs occurs evenly, therefore all friction discs are replaced during the overhaul. Specialists recommend to replace Teflon rings of the rear cover. Brake bands (the pair F2 and F3) are replaced in the process of each overhaul of the transmission with burnt ATF. Servo pistons are replaced together with brake bands. The damaged pump cup (seal) is the most popular part for repair among seals and sealing strips. One of the most common problems takes place in the needle bearing located between the hub 570 and drum 554 in the Е2 package . The clutch package E2 (4th) is the most popular part for replacement among spare parts.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chery	A3	09-16	4 SP FWD	L4 1.8L 2.0L
Chery	A5	06-10	4 SP FWD	L4 2.0L
Chery	CHANCE	13	4 SP FWD	L4 2.0L
Chery	COWIN 3	10-16	4 SP FWD	L4 2.0L
Chery	DONGFANGZHIZI	06-14	4 SP FWD	L4 2.0L
Chery	DONGFANGZIHIZI	12-13	4 SP FWD	L4 2.0L
Chery	EASTAR A6	09-10	4 SP FWD	L4 2.0L
Chery	NICHE	13	4 SP FWD	L4 2.0L
Citroen	C2	07-13	4 SP FWD	L4 1.6L
Citroen	C3	06-16	4 SP FWD	L4 1.6L
Citroen	C3 PICASSO	11-16	4 SP FWD	L4 1.6L
Citroen	C4	04-16	4 SP FWD	L4 1.6L 2.0L
Citroen	C5	00-16	4 SP FWD	L4 1.7L 2.0L
Citroen	C-TRIOMPHE	06-13	4 SP FWD	L4 2.0L
Citroen	DS3	09-16	4 SP FWD	L4 1.6L
Citroen	ELYSEE	03-14	4 SP FWD	L4 1.6L
Citroen	EVASION	00-01	4 SP FWD	L4 2.0L
Citroen	FUKANG	05-08	4 SP FWD	L4 1.6L
Citroen	PALLAS	07-13	4 SP FWD	L4 2.0L
Citroen	XANTIA	00-01	4 SP FWD	L4 1.8L 2.0L V6 2.9L
Citroen	XM	0	4 SP FWD	L4 2.0L 2.1L V6 2.9L
Citroen	XSARA/XSARA PICASSO	00-11	4 SP FWD	L4 1.6L 1.8L 2.0L
KIA	206 BESTARI	06-09	4 SP FWD	L4 1.4L
Nissan/Datsun	PLATINA	02-10	4 SP FWD	L4 1.6L
Peugeot	2008	13-16	4 SP FWD	L4 1.6L
Peugeot	206	98-15	4 SP FWD	L4 1.6L
Peugeot	207	06-16	4 SP FWD	L4 1.6L
Peugeot	208	12-16	4 SP FWD	L4 1.6L
Peugeot	3008	12-14	4 SP FWD	L4 1.6L
Peugeot	306	00-02	4 SP FWD	L4 1.8L 2.0L
Peugeot	307	01-15	4 SP FWD	L4 1.6L
Peugeot	308	07-16	4 SP FWD	L4 1.6L 2.0L
Peugeot	405	99-15	4 SP FWD	L4 1.6L
Peugeot	406/406 COUPE	00-05	4 SP FWD	L4 1.7L 1.8L 2.0L
Peugeot	407	04-11	4 SP FWD	L4 2.0L
Peugeot	408	10-16	4 SP FWD	L4 1.6L 2.0L
Peugeot	806	01-02	4 SP FWD	L4 2.0L
Rely	V5	09-16	4 SP FWD	L4 2.0L
Renault	CLIO	98-16	4 SP FWD	L4 1.4L 1.6L 2.0L
Renault	ESPACE	01-03	4 SP FWD	L4 2.0L
Renault	KANGOO	97-16	4 SP FWD	L4 1.4L 1.5L 1.6L
Renault	LAGUNA	03-07	4 SP FWD	L4 1.8L 1.9L 2.0L
Renault	MEGANE	02-14	4 SP FWD	L4 1.4L 1.5L 1.6L 1.9L 2.0L
Renault	MODUS	04-12	4 SP FWD	L4 1.6L
Renault	SAFRANE	00-01	4 SP FWD	L4 2.0L 2.2L
Renault	SANDERO	11-15	4 SP FWD	L4 1.6L
Renault	SCENIC	00-11	4 SP FWD	L4 1.5L 1.6L 1.9L 2.0L
Renault	SYMBOL/THALIA	00-13	4 SP FWD	L4 1.4L 1.6L
Samsung	SM3	09-11	4 SP FWD	L4 1.5L

How to repair this transmission (Videos)

Al4 Gear box , changing Valves

DP0 and AL4 valve body

AL4(DP0) rebuild

AODE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission AOD had been installed on well-known Crown Victoria with 4.6 liter engine since 1980, it was in production for 15 years. In 1993 it was updated into electronic AOD-E version. After that, it was modified into the 4R70W (1995) without significant changes and was used until 2006. The last modification of this popular series named 4R75W was released in 2003.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		8,5	3,5	Mercon V

Technical issues and repair guidelines

This family of automatic transmissions rarely gets in repair services and mainly requires replacement of some spare parts. But it is not because these transmissions are extremely reliable and durabile, but on the contrary, once these transmissions get damaged by overheating, they should be replaced rather than rebuilt.

Typical problems of these automatic transmissions (from AOD-E to 4R70W) include the following: wear-out of seals and rings, that results in oil pressure drop in clutch packs, oil overheating caused by the pressure shortage, clogging of the valve body, wear-out of the brake band and backlash of servo pistons, wear-out of the torque converter locking and backlash of the pump shaft with wear-out of seals and bushings, ageing of rubber and plastic elements.

Owners of this automatic transmission have to change oil and filter every 30-50 thousand kilometers, perform the torque converter repair, install additional transmission cooling system, and when having the slightest suspicion regarding shortages in oil pressure, it is necessary to visit the nearest repair shop. A typical overhaul of the "old" AOED transmission, except spare parts, includes the following: Kit of gaskets and seals \ Overhaul kit. Since 2003, transmissions of the 4R70W/4R75E/W series mainly have been delivered to repair shops.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	MUSTANG	95	4 SP RWD	V6 3.8L V8 5.0L

How to repair this transmission (Videos)

4R75E Transmission Teardown Inspection

4R75-E Transmission Repair

4R75E

AODE 4R70W Class part 1 lesson 4

AODE 4R70W Class part 2 lesson 4

AODE 4R70W Class part 2 lesson 5

AODE 4R70W Class Part 2 Lesson 6

AODE 4R70W Class Part 2 Lesson 7

4R70W Valvebody Overhaul and Tips

4R70/4R75W EPC Changes

Loss of 4th Gear Concerns

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Vacuum test 4R70E, 4R70W, 4R75E, 4R75W, AODE
pdf	drive.google.com	Repair manual Ford AODE

AW5550SN Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission AW55-50SN was developed by Aisin specialists at the end of the last century as an exclusive 5-speed automatic transmission for non-Toyota FWD vehicles with engines from 2 up to 3 liters. After update of the valve body and computer settings, this transmission as AF23 and AF33 was installed on GM models: Daewoo-Chevrolet (Captiva, Epica, Laketti ...), Saab, Opel and American Saturn and Suzuki. The testing of this unique transmission was performed since 2000 on Volvo cars (on C70, both the 40, 70 and S60s and S80s).

Part of the design solutions for this tranmsission are adopted from its successful predecessor - the 4-speed AW50-40. The transmission was so successful that even its competitors installed AW55 for their popular cars, simultaneously releasing their RE5R05A (JR507E) (Nissan-Jatсo) and 5L40E / 5L50E (GM-Europe).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	FWD	330	7,1	3,5	Type T-IV

Technical issues and repair guidelines

The torque converter repair after running 200 thousand kilometers is a routine procedure. Repair kits of gaskets and seals for this transmission are produced by many manufacturers. Frictions are replaced by whole packages. Packages of clutches and brakes are designed in a fairly balanced manner and wear out at about the same time. The complete kit of frictions is also ordered when linings of remaining (unburned) clutches are soaked with burnt oil.The most popular parts for replacement are the pump seal and the pump cover bushing. The first problem occurs when operating in the oil starvation mode and with the wornout torque converter. Almost each overhaul is accompanied with the torque converter cutting and its subsequent rebuilding. The lock-up friction lining wears out quite rapidly causing many issues in the AW55-50.

There are many signs of the faulty valve body, but the reason for the majority of premature (before 150-200 thousand kilometers) problems of the mechanical components in this transmission lies in insufficient pressure of the ATF coming from the valve body. Dirt in the ATF and high temperatures, wear out and clog channels of valves and solenoids of the valve body. Worn-out areas are clogged with dirt and plungers get wedged, so the ATF does not reach clutch packages and the torque converter lock-up.The valve body repair and cleaning should be performed as early as possible (when you notice the first signs of improper operation) in order to avoid typical and fatal problem, namely the valve body housing wear-out. For rebuilding of transmission units in "old" cars, specialists usually order the kit of frictions, steel discs, and repair kit of gaskets and seals (overhaul kit). At the same time specialists replace the brake band (because friction linings are soaked with burnt oil). The pressure shortage from oil, coming from clogged valve body may have a negative impact on bushings. The pump cover bushing is the first to wear out. In rare cases planetary gear bushings are pressed out.

Mechanical elements of the AW55-50SN transmission are very reliable or even may be called “flawless”. The evidence of reliability lies in the factor, that for 90% cases of transmission components repair, specialists order only the repair kit of bushings. But if a driver frequently overloads the transmission, then repair specialists sometimes have to rebush or replace worn-out rear planetary gear.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	EQUINOX	04-09	5 SP F/4WD	V6 3.4L
Opel / Vauxhall	ANTARA	06-16	5 SP F/4WD	L4 2.0L 2.4L V6 3.2L
Opel / Vauxhall	SIGNUM	03-08	5 SP F/4WD	L4 2.2L V6 3.0L 3.2L
Opel / Vauxhall	VECTRA	02-09	5 SP F/4WD	L4 2.2L V6 3.0L 3.2L
Pontiac	TORRENT	04-09	5 SP F/4WD	V6 3.4L
Saturn	ION	03-04	5 SP FWD	L4 2.2L
Saturn	VUE	02-03	5 SP F/4WD	V6 3.0L
Suzuki	XL-7	04-08	5 SP F/4WD	V6 3.6L

How to repair this transmission (Videos)

AW55-51SN / RE5F22A Teardown Inspection

AW55-51SN / RE5F22A Solenoid Repair

AW55-51SN / RE5F22A Solenoid Repair PART 2

AW55 Solenoid Adjustment, Diagnosis and Repair

AW-55SN Linear Solenoid Repair

AW55-51SN / RE5F22A Transmission

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout AW5550SN
video	Sonnax	AW 55-50/51SN Solenoid Bracket Identification & Installation
web	Sonnax	AW 55-50/51SN Pressure Tap Locations
web	Sonnax	AW 55-50 Differences Between Manufacturers Part 2
web	Sonnax	AW 55-50 Differences Between Manufacturers Part 1

AW5040LE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed hydraulically controlled automatic gearbox AW50-40 produced by Aisin Warner was designed in the 90-s for well-known "family" vehicles of the middle class with 2-liter engine: Renault Laguna, Volvo (С70), Saab, Opel. This gearbox is also installed on KIA and Daewoo. This gearbox can be easily identified according to the pan form. According to GM classification, this gearbox is known as AF14 (AW50-40LE).

The AW50-40LE version has enlarged hubs, drums, overrunning clutches, planetary gears, in order to transmit higher torque. In 1998, the new modification AW50-42LE (AF22) was released in order to expand the usage of this gearbox for engines with the capacity up to 3.0 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	250	12,5	6	Type T-IV

Technical issues and repair guidelines

In addition to the filter replacement and torque converter rebuilding, overhauls usually require repair kit of gaskets and seals (Overhaul kit). Besides the repair kit of gaskets, specialists also order a complete kit of frictions. It is especially needed in situations when burnt ATF from Direct and Forward frictions reach easily wornout frictions of other packages.The complete repair kit Masterkit is frequently ordered for a full reassembly of this tranmsission.

Typical repair areas in AF17 - AF22 (AW50-40, AW 50-42)

This gearbox is quite sensitive to ATF cleanness and as the filter is replaced in case of the gearbox disassembly, then old cars are provided with a cooling line of the magistral main filter. Typical problem of old AW50-40 components include the following: drum (Forwad/Direct) – wear-out of the fitting area, cracks in the welding joint area. This problem leads to burning of frictions and steel discs of this drum. Forward and Direct packages are replaced more frequently than others. Steel discs also get burnt in the abovementioned packages.The brake band is another component which is replaced in the process old cars overhauls in addition to replacement of spare parts and frictions. This band is also included in the list of recommended spare parts in case of burnt oil. Improper operation of the band in addition to kicks in the process of gears shifting also leads to rapid wearout of the drum Underdrive - С3.

The friction lining wears out unevenly leading to bushings beating and wear-out of pump units. Non-operating or worn-out torque converter lock-up leads to clogging, ageing and wearout of valves of the valve body and solenoids. If the gearbox operates for a long time with this problem, then shafts and pump get overheated, operate without oil, and as a result of vibrations overheat and damage bushings.Seals of the pump and semi-axles are replaced during each visit to repair services. If the problem with leaking seals and damaged bushing is neglected, then the whole pump is replaced. A common reason of all issues related to the oil pressure loss lies in malfunction and contamination of the valve body or solenoids. Usually this problem is related to large wear particles in ATF and the faulty torque converter.

Specialists like this gearbox for its reliability and simplicity. It operates during the whole lifespan of the car in which this gearbox is installed. But it is required to monitor the oil level and its cleanness, otherwise negligence may lead to pressure losses in the line and wear-out of bushings, spare parts and damage of bearings, that results in the necessity to perform the overhaul.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Opel / Vauxhall	ASTRA	00-04	4 SP FWD	L4 2.0L 2.2L
Opel / Vauxhall	VECTRA	00-02	4 SP FWD	L4 1.8L 2.0L 2.2L V6 2.5L 2.6L
Opel / Vauxhall	ZAFIRA	99-14	4 SP FWD	L4 2.0L 2.2L
Suzuki	SX4	06-12	4 SP FWD	L4 2.0L

AW6040LE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission AW60-40LE was designed by Aisin Warner in 1995 for FWD vehicles (Suzuki, Opel, Daihatsu, Fiat) equipped with engines up to 1.6 liters. After testing on Suzuki Estima, this transmission was widely installed on numerous models of different brands. According to GM classification AW6040LE is known as AF13.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	180	7,5	3,5	Type T-IV

Technical issues and repair guidelines

The worn-out torque converter lock-up requires repair after 200-300 thousand kilometers (depending on the driving style).

In addition to the filter, during the overhaul transmission specialists usually order the following:

-Repair kit of gaskets and seals

- Complete kit of fricion plates

-For the reassembly procedure specialists also order the kit of steel discs

In many cases, the main problem lies in two burned clutch packages: Forward and Package 3-4 (friction clutches and steel discs of packages Forward and 3-4).The brake band is ordered together with the kit of friction clutches. When the burnt oil comes to the friction linings, they start operating with noticeable jerks or slippages. The kit of 4 plastic washers of supporting bearings is replaced during the overhaul of ageing transmission.With regard to electrics, typical problems occur in valve bodies. Valve body units should be reassembled and cleaned in the process of each overhaul. Transmission repair specialists also should replace the gaskets.

The solenoid “shift” (gear shifting) is frequently replaced because of the end of service lifespan. The solenoid of the torque converter lock-up is also often replaced. Together with two above mentioned solenoids specialists replace the solenoid-electric controller EPC/SLT (main pressure).The reason for premature wear-out is assumed to be a long-time operation in contaminated and overheated oil with the worn-out torque converter lock-up.

The valve body usually is quite durable, but aggressive accelerations and driving with worn-out friction clutches may bring closer the replacement time. If there is smell of burning oil, then in most cases the problem lies in packages the Forward and 3-4.

Generally, the family of automatic transmissions AW60-40LE is considered to be maintenance-friendly as the majority of 4-speed Aisin transmissions. Thus, after the diagnostics and replacement of all worn-out parts it can operate for a long period of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Opel / Vauxhall	ASTRA	00-04	4 SP FWD	L4 1.4L 1.6L
Opel / Vauxhall	TIGRA	0	4 SP FWD	L4 1.4L
Suzuki	AERIO	02-07	4 SP F/4WD	L4 1.5L
Suzuki	CULTUS	00-03	4 SP FWD	L4 1.5L 1.8L
Suzuki	ESTEEM	95-02	4 SP FWD	L4 1.6L

How to repair this transmission (Videos)

AW 60-40LE

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Vacuum test AW 60-41SN

A960E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission А960Е with longitudinal positioning was designed in 2005 by Aisin Co for rear-driven Lexus cars (sedans GS300, IS250 and IS300) with 2.5-3 liters. It also operates on right-hand Toyota MARK X. This transmission is developed on the principle of modules on the basis of the 5-speed A750 transmission together with 6-speed A761, but intended for a lower torque (190-300 Nm). The main competitor of this transmission is ZF6HP19-21. According to Aisin Co classification, this transmission for Lexus can be named TB-65SN.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD	314	8,5	4,1	Toyota WS

Technical issues and repair guidelines

Frequently used sports mode of this transmission quickly leads to the wear-out of the torque converter friction and fluid contamination. If the piston friction turns out to be worn-out, then some glue components reach the fluid, that makes some instant negative impact on the valve body functionality. Contrary to the 6НР19 unit with the torque converter having several double-sided frictions for the slippery mode, the A960E transmission has a single friction glued to the piston, that requires monitoring of the wear-out and when having any suspicions related to lack of the torque converter lockup, therefore well-timed diagnostics and spare parts replacement procedures should be implemented.

Typical overhaul of А960Е requires replacement of the following parts:

- Kit of gaskets and seals, without pistons.

After burning of frictions they are all replaced with rubber seals. The contaminated fluid leads to wear-out of teflon rings. If these rings wear out, they start contaminating transmission fluid.

- Kit of frictions, which are replaced in most cases.

- Kit of steel discs which together with friction discs and repair kit of gaskets represents the complete repair kit (Masterkit).

Complete and timely replacement of spare parts in this durable transmission adds up to 70% of increased resource before the overhaul.

- The pan gasket is ordered each time when changing the ATF and removing the pan for the filter replacement.

The valve body repair with replacement of solenoids always implies the torque converter rebuilding. The torque converter spare parts are the first to exhaust their resource.One more problem that may be caused by vibrations from worn-out friction of the lock-up mechanism that damages the pump seal and bushing itself. The typical soft point of this transmission is the oil pump unit with leaking seal, and if it is neglected the problem spreads to the pump bushing. Further driving without timely repair of the torque converter leads to the loss of the pump itself. It is often accompanied by wear-out of the torque converter lockup solenoid.

Electrics in А960

The rebuilding of this old А960 unit includes the replacement of the linear solenoids. Selection of solenoids for the А960 unit is performed in accordance with VIN-code of the car. The peculiar feature of this reliable 6-speed automatic transmission is that the driver does not receive any noticeable signals related to the necessity to replace worn-out spare parts (the torque converter friction and solenoids which can not endure aggressive accelerations with the "slipping mode" of the torque converter clutch).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LEXUS	GS	05-12	6 SP RWD	V6 3.0L
LEXUS	IS	05-12	6 SP R/4WD	V6 2.5L 3.0L

How to repair this transmission (Videos)

LEXUS IS 250 repair transmission A960E

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Solenoid identification A960E
pdf	www.at-manuals.com	Repair manual A960E
web	www.at-manuals.com	Stall test A960E
web	www.at-manuals.com	Pockets A960E
pdf	Sonnax	Valve Body A960E
web	Sonnax	Diagnosing Solenoid Performance Faults in A960

A6LF1 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic transmission A6LF1 is a part of 6-speed transmissions family (A6LF2/3, A6GF1, A6MF1 /2) produced by Hyundai. This transmission is an expensive and comfortable alternative to the 5-speed automatic transmissions A5HF1 (A5GF1). These transmissions had been tested since 2009 on a limited series of Hyundai Avante HD\MD and after 2-3 years of modifications were installed on luxury FWD and AWD cars Hyundai (Sonata, Opirus...) and Kia models with engine capacity from 1.4 up to 3.8 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/4WD	323	7,8	4	SP-IV

Technical issues and repair guidelines

Aggressive accelerations and critical overheats may lead to replacement of rings and valve body gaskets. After covering over 150 thousand kilometers replacement of the whole repair kit is considered to be a routine procedure. The aim of this measure intended for protecting solenoids which have to deal with higher loads caused by increasing oil leakages through sealings. The main signs of the problem are the following: wear-out of the torque converter lock-up, rapidly contaminating transmission fluid, and issues with gear shifting. The valve body disassembly usually indicates critical contamination and sticking of valves.

Insufficient oil pressure (caused by problems with the valve body or leaks of ATF through rings, jointing edges and as a result wear-out of solenoid valves) in most cases leads to burning of friction elements with Overdrive and Underdrive discs, but often drivers neglect this problem, resulting in replacement of all friction clutches and steel discs which operated in burnt ATF. Contaminated ATF from this package damages corresponding valves and solenoids of the valve body.

The vulnerability of the A6MF1/2 transmissions resides in burning of clutches 3-5\R and 2-6. For replacement of these burning packages, Hyundai released the kit of "Power Pack" friction elements with steel and bearing discs.The Overdrive is also frequently replaced by repair specialists. The problem is explained by overloads caused by contaminated fluid, resulting in wear-out of teflon rings on the rear cover and pressure losses in packages.A typical problem for Hyundai differentials is related to damage of splineways of the differential body under the condition of longtime and frequent wheels slippages. During the first years of testing, the main problem lies in the valve body and solenoids (problem identical to ZF transmission ZF6HP from which the valve body operation principle was adopted).

The most failure-prone solenoids are the following:

1. EPC solenoid

2. TCC solenoid.

3. Shifting solenoids

Another frequent problem for this transmission (as well as for other 6-speed automatic transmissions) is related to the torque converter clutch wear-out. The more often drivers use aggressive accelerations, the closer this transmission to the repair shop.

The valve body may be considered a soft spot in the electrical part of the A6MF2 \LF2 transmission. As in all 6-speed automatic transmissions, the A6LF1 valve body is very sensitive to overheating and contaminated ATF, which first of all may be provoked by wear-out of the torque converter friction and clutch packages and in chain order lead to (pressure shortage from solenoids and the valve body) more rapid wear-out of frictions in packages of clutch and braking. Problems at the early stage are usually solved by repair and cleaning of the valve body and solenoids, opening of the torque converter for replacement of spare parts. In more complex repair cases, transmission specialists have to repalce solenoids.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hyundai	AZERA	11	6 SP FWD	V6 3.3L
Hyundai	GRANDEUR	11-16	6 SP FWD	V6 3.0L
Hyundai	MAXCRUZ	13-16	6 SP F/4WD	V6 3.3L
Hyundai	SANTA FE	12-16	6 SP 4WD	L4 2.0L V6 3.3L
Hyundai	TUCSON	10-16	6 SP FWD	L4 2.0L
Inokom	TUCSON	15-16	6 SP FWD	L4 2.0L
KIA	CARNIVAL	14-16	6 SP FWD	V6 3.3L
KIA	K7	16	6 SP FWD	V6 3.0L
KIA	OPIRUS	11-15	6 SP FWD	V6 3.0L
KIA	OPTIMA	13-16	6 SP FWD	L4 2.0L
KIA	SORENTO	14-16	6 SP F/4WD	V6 3.3L

How to repair this transmission (Videos)

Sportage A6lf1

A6LF1/2/3

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme A6LF1
pdf	Sonnax	Valve Body Layout A6GF1, A6LF1/2/3, A6MF1/2

A650E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission А650Е with the langitudinal positioning has been installed since 1998 on RWD Lexus (as AW 35-51LS) and for some period of time on 4WD cars such as Land Cruisers and Hilux. This robust automatic transmission had been installed on the RWD and right-handed Toyota produced from 1998 until 2007. The А650Е unit replaced the first 5-speed transmission А350 which was the updated version of 340-series.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/4WD	430	8,9	3,8	Toyota Type T-IV

Technical issues and repair guidelines

The А650Е unit is a rare “guest” in repair shops. Partly this is due to the fact that this transmission was so-called “pioneer” used for testing new technologies of linear solenoids, increased temperatures and slipping of the torque converter lockup, and partly because all Aisin products with longitudinal positioning are traditionally quite durable. Many units and spare parts from А340 can be used in the А650Е modification.

It is a very rare case when all gaskets and seals from the overhaul kit and friction components in 2nd Brake package are changed in the dry-operating А650Е transmission.Occasionally, long-time operation of the transmission with a leaking seal leads to necessity of the pump and pump bushing replacement. This problem is caused by the wear-out of the torque converter friction, where spare parts are untimely replaced. This automatic transmission was replaced by 5-6-speed А750Е and А761Е.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LEXUS	GS	98-05	5 SP RWD	V6 3.0L V8 4.0L 4.3L
LEXUS	IS	00-05	5 SP RWD	V6 3.0L
LEXUS	LS	98-03	5 SP RWD	V8 4.0L 4.3L
LEXUS	SC	98-05	5 SP RWD	V8 4.0L 4.3L
Toyota	ALTEZZA/ALTEZZA GITA	00-05	5 SP R/4WD	L4 2.0L V6 2.5L 3.0L
Toyota	ARISTO	00-04	5 SP RWD	V6 3.0L V8 4.3L
Toyota	BREVIS	01-07	5 SP RWD	V6 2.5L 3.0L
Toyota	CELSIOR	00-03	5 SP RWD	V8 4.3L
Toyota	CENTURY	97-16	5 SP RWD	V12 5.0L
Toyota	CENTURY	00-04	5 SP RWD	V12 5.0L
Toyota	CHASER	00-01	5 SP RWD	V6 2.5L
Toyota	CRESTA	00-01	5 SP RWD	V6 2.5L
Toyota	HILUX	00-05	5 SP R/4WD	V6 3.4L
Toyota	LAND CRUISER	00-02	5 SP 4WD	V6 3.4L
Toyota	MARK II	00-04	5 SP RWD	L4 2.0L 2.2L V6 2.5L
Toyota	PROGRES	01-07	5 SP RWD	V6 2.5L 3.0L
Toyota	SOARER	01-05	5 SP RWD	V8 4.3L
Toyota	SUPRA	2	5 SP RWD	V6 3.0L
Toyota	VEROSSA	01-04	5 SP RWD	V6 2.0L 2.5L

How to repair this transmission (Videos)

Failure in depth tear down

Transmission Fluid Change

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Solenoid identification A650E
pdf	www.at-manuals.com	Scheme A650E
web	www.at-manuals.com	Stall test A650E
pdf	drive.google.com	A650E Repair manual
pdf	drive.google.com	A650E_A750EF_A761E manual

A760E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic transmission A761E, (A760E -F \Н) with longitudinal positioning is similar to the 5 speed А750 in terms of design. It has been tested since 2003 with 8-cylinder engines of Toyota Celsior and with Lexus LS430. This powerful 6-speed RWD transmission was produced in pair with economical А960, intended for lower torque (200-310 Nm). This automatic gearbox together with А761-А960 are direct competitors of ZF 6HP26 and 6HP19 units.

A760E is a basic modification for RWD units,

- A760F – for AWD SUVs of Toyota and Lexus,

- A760Н – is a rare modification for 4WD light motor vehicles.

- in 2006, the upgraded А761 unit was released. It is notable for perfect operational parameters of a new valve body and solenoids.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD/4WD	420	11	4	Toyota WS

Technical issues and repair guidelines

All rear-drive Aisin transmissions are distinguished by design reliability, especially those units which are installed on Lexus cars, therefore this transmission is rare in the repair service and there is no much information on the overhaul statistics. Problems of the А761 unit are related to already known issues with А750Е. These problems are caused the fluid overheating or its contamination by friction dust. Many experts consider А760 for rear-drive cars to be extremely durable as all Aisin automatic transmissions. Components of this transmission can operate properly for more than 300 thousand kilometers without overhaul, under the condition that they operate with comparatively clean oil.

Typical issues in A761

Commonly, together with spare parts repair specialists also replace the package of friction discs, burnt as a result of pressure shortage caused by clogging of the solenoid or valve body. All frictions are usually replaced in case of burnt transmission fluid. When we talk about the most problematic elements in first generations of the А750-А761 family, we should point out relative dependency of electrical components of this tranbsmission (valve body) from from the fluid condition and wear-out of the torque converter lockup. All problems with shifting are usually related to spoilt and worn-out valve body. Therefore, any diagnostics and rebuilding procedures start with testing and cleaning of the valve body and solenoids. All valve body problems start with worn-out elements of the torque converter. The torque converter is repaired as well.

Valve bodies for А750, А761 and А960 are identical from the outside. But the internal design, computer settings and solenoids (as well as their quantity) have been constantly modified during testing, therefore selection of solenoids for replacement (as well as valve body selection) is performed according to VIN-code. The number 8870 is displayed on plates of the А761 transmission.The valve body replacement for this unit is relatively rare in comparison with European manufacturers on similar automatics (722.6 and ZF-6HP26). Generally, reassembly and cleaning of the valve body and cleaning-replacement of solenoids are performed when repairing the А761 unit. First and foremost, repair specialists have to replace solenoids. These solenoids have the valve, receiving the main load from contaminated fluid coming from the torque converter. Each replacement procedure of solenoids is accompanied by the torque converter repair and replacement of the lock-up friction.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
LEXUS	LX	11	6 SP 4WD	V8 4.6L
Toyota	CELSIOR	03-06	6 SP RWD	V8 4.3L
Toyota	SEQUOIA	09-12	6 SP R/4WD	V8 4.6L

How to repair this transmission (Videos)

A750 A761 Introduction

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Manual A760E
pdf	www.at-manuals.com	Vacuum test valvebody A760E
pdf	www.at-manuals.com	Scheme A760E
pdf	Sonnax	Valve Body A760H
pdf	Sonnax	Vacuum test A760E/F/H, A761E
web	Sonnax	Diagnosing Solenoid Performance Faults in A761
web	Sonnax	Toyota A750E-A761E Identification Guide

A750E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

This 5-speed automatic transmission А750Е\ F produced by Aisin Warner has been used since 2002 for powerful rear- and full-drive SUVs Land Cruiser, 4Runner and Lexus. The А750F (4WD) is the most frequently repaired transmission mated to engines with capacity equal to 4.7 liters. The А750 transmission replaced the 5-speed А650Е from the previous generation and “invincible” А340 series. In terms of design, this transmission is similar to 6-speed А761 and А960 units. The А750 modification can be paired with 1GR-FE (for lower torque) and 2UZ-FE engines in 4WD cars.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/4WD	485	12	4	Toyota T-IV

Technical issues and repair guidelines

This transmission has almost flawlessly matched gear ratio, tested cooling and ATF heating systems. The acceleration in the sport mode turns on slipping torque converter lockup starting at the 3-rd gear. It doubles the time before the torque converter repair in comparison with competing 6HP26 units.

The fluid change (Toyota WS) and filter replacement in A750 is performed with the help of partial and full replacement methods. The transmission electrics has delicate settings and sensitive to the oil level. Solenoids of this transmission can exhaust its resource prematurely and often get replaced, especially in gearboxes during first two years of series production. But in general, this transmission as well as majority of rear-drive Aisin automatic transmissions was produced to be "invincible".

Typical problems in A750E

The most common ordered repair kits for the first overhaul of the А750F unit, includes the following:

- Kit of gaskets and seals, Overhaul Kit

- Kit of all friction components

Overhauls of long-time neglected transmissions are notable for the fact that friction components should be replaced with all solenoids. The first package that gets burnt with cover plates: Forward С1 frictions. Then comes the turn of the В1 braking package.Other frequently burning frictions are located in Direct, C3 and 2nd brake packages.

Different problems with the torque converter, valve body and solenoids may occur as a result of long-time overheating or aggressive driving style on the off-road territory or on snow after 70 - 80 thousand kilometers.Transmission operation with worn-out torque converter clutch may lead to vibrations and fluid leakages through the pump seal. At the same time, the problem with the pump bushing occurs, and later you will have to deal with the pump failure. Valve bodies of А750, А761 and А960 have been constantly modified, improving their design, therefore selection of valve bodies and solenoids for replacement is performed specifically for each car according to its VIN-code. In general, the А750F unit is adjusted quite accurately for the torque converter and the valve body. Afterwards, you can drive for 150-200 thousand kilometers without serious problems for car owners, if ATF condition is controlled.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Toyota	4 RUNNER	03-08	5 SP R/4WD	V6 4.0L V8 4.7L
Toyota	MARK X	04-09	5 SP R/4WD	V6 2.5L
Toyota	SEQUOIA	05-08	5 SP R/4WD	V8 4.7L

How to repair this transmission (Videos)

A750E/F Valve Body Installation

750, 760, AB60 TRANSMISSION FILL

A750E/F Transmission Service

A750 A761 Introduction

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Manual A750E
pdf	www.at-manuals.com	Vacuum test valvebody A750E
pdf	www.at-manuals.com	Scheme A750E
web	www.at-manuals.com	Stall test A750E
web	www.at-manuals.com	Clutch application A750E
pdf	Sonnax	Valve Body Layout A750E
pdf	Sonnax	Vacuum test A750E/F
web	Sonnax	Diagnosing A750E/F 2-3 Flare After Overhaul
web	Sonnax	Toyota A750E-A761E Identification Guide
pdf	drive.google.com	A650E_A750EF_A761E manual

A4LD Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic gearbox Ford A4LD was designed for RWD vehicles (Explorer, Mazda pickup cars and many others) with engines from 2.5 up to 4 liters. This family of transmissions is manufactured in Bordeaux, France. After the update in 1995, this gearbox was provided with an electronic control, the letter "Е" was added to its name (A4LD-Е). In 1997, this gearbox became fully equipped with an electronic control unit and changed its name in accordance with a new classification- 4R44E,and after the update of several units, the 4R55E modification was released. Spare parts for repair of these gearboxes are interchangeable.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		9,5	4	Dexron VI

Technical issues and repair guidelines

The torque converter in these transmissions is the first component to be replaced during repair procedures. In most cases, transmission specialists order the Masterkit repair kit to fix this transmission. This kit includes all gaskets and seals, rings and friction components with discs, except filter and brake bands, which are ordered separately. Repair kits contain all necessary gaskets and spare parts of the valve body, other gearbox components and pan, to replace the old rubber, paper gaskets and plastic of the transmission, which served for more than 10 years.

This transmission is handed in for repair after failures of the brake band О.D.\Intermediate and the drum Overdrive. The drum Overdrive is also considered to be a soft spot and gets out of order together with the brake band and Servo piston of the brake band. When solving the abovementioned problems, specialists also replace the brake band piston INTM./ O.D.

Vibrations and overheating of this drum may lead to replacement of not only friction elements of the package Overdrive, steel discs, and bearing disc, but also of the pump support.In many cases, packages get burnt because of worn-out pump bushing and insufficient pump productivity. This problem can be detected by means of the leaking seal.

The repair of electrical components consists of replacement of EPC solenoids, solenoids shift (4), solenoids of the torque converter locking (TCC), which reached the end of their service life.The valve body often causes insufficient (on bushings) or excessive pressure. The valve body gets clogged with friction dust from the worn torque converter. If the torque converter friction is worn out to the glue layer, then it significantly speeds up the wear-out and clogging of solenoids and the valve body.The most replaceable clutch discs are friction elements of the Forward Clutch package and corresponding steel discs, which twofold outrun the package Direct in sales, other friction elements are replaced more rarely.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	AEROSTAR	95	4 SP R/4WD	V6 3.0L 4.0L
Ford	TRANSIT	0	4 SP RWD	L4 2.5L
Mazda	NAVAJO	91-94	4 SP RWD	V6 4.0L
Mazda	PICKUP	94	4 SP RWD	L4 2.3L V6 3.0L 4.0L
MCW	METROCAB	00-01	4 SP RWD	L4 2.5L

How to repair this transmission (Videos)

Teardown Inspection

5R44E 2-3 shift

5R55E Valve Body Shift Kit Installation

servo bore problems

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Remove and Install A4LDE
web	www.at-manuals.com	Scheme C-3
web	www.at-manuals.com	Clutch application
pdf	Sonnax	Valve Body Layout 4R/5R44E, 4R/5R55E
pdf	Sonnax	Vacuum test 4R44E-5R55E

A4AF3 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission A4AF-3, A4BF-3 was designed in 2000 by Hyundai specialists and was supposed to become a successor of the A4AF1 for FWD medium vehicles such as Hyundai Matrix, Elantra, Accent, with engine up to 2 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	190	6,3	4	SP-III

Technical issues and repair guidelines

This transmission is considered to be very reliable, enduring long-time operation with contaminated transmission fluid. After a proper overhaul with spare parts reassembly specialists can give 1-2 years warranty. Many spare parts for A4AF3, A4BF3 transmissions are interchangeable with the whole A4AF family of automatic transmissions.The list of common spare parts includes the following: closed filter with felt, which is replaced in the process of each reassembly of the transmission that covered 150- 180 thousand kilometers; the brake band, which is replaced with the whole set of friction components when smelling the burnt ATF (Brake bands for engines up to 1.8 liters and over 1.8 liters are different), the brake band is replaced with the seal when operating for a long time with worn-out spare parts of the torque converter; in many cases specialists order the kit of bushings for the overhaul.

Seal boots are unified and can be applied for all relative automatic transmissions from КМ175 to F4A33, they are ordered during each rebuilding. If seals are replaced, but the torque converter is left untouched, then after a short time the seal will start leaking again and, as a result, it will be required to reassemble the oil pump. Friction elements in the Direct Clutch\ Forward packs burn 3 times more frequently. In most cases, all friction components are ordered for complete overhaul.

Another problem of the A4AF1 became a real “headache” for specialists in the process of the A4BF3 transmission repair: the drum gets burnt in each 5-th automatic transmission which comes to repair services, because of worn bushings and consequent oil leakage.Typical design problem of the Overdrive unit lies in damage of bearings caused by side loads from the differential.

Specialists often have to repalce the whole set of 6 solenoids and wiring. Even if the problem occurs in only one solenoid, technicians have to replace all of them because of short resource of other solenoids.Sometimes the problem of one of the linear pressure solenoids may lead to harsh shifting or forced actuation of the 3-rd gear without error codes. Problems usually lie in the fact that the solenoid valve wears out the channel because of contaminated ATF, starts hovering and at some moment gets wedged. Cleaning only contributes to the problem and the repair does not cover expenses. Generally this transmission is reliable like Hyundai cars when avoiding unnecessary overloads and overheating.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hyundai	ATOZ	01-12	4 SP FWD	L4 1.1L
Hyundai	AVANTE	00-16	4 SP FWD	L4 1.6L
Hyundai	AVANTE XD	00-06	4 SP FWD	L4 1.5L 1.6L 1.8L
Hyundai	AVEGA	07-10	4 SP FWD	L4 1.5L
Hyundai	CLICK	02-10	4 SP FWD	L4 1.3L 1.4L 1.5L 1.6L
Hyundai	GETZ	04-08	4 SP FWD	L4 1.3L 1.4L 1.6L
Hyundai	LAVITA	01-07	4 SP FWD	L4 1.5L 1.6L
Hyundai	SONATA	01-05	4 SP FWD	L4 2.0L
Hyundai	VERNA	00-11	4 SP FWD	L4 1.3L 1.4L 1.5L 1.6L
KIA	AVELLA	00-02	4 SP FWD	L4 1.3L 1.5L
KIA	CLARUS	00-02	4 SP FWD	L4 1.5L
KIA	FORTE	03-16	4 SP FWD	L4 1.6L 1.8L
KIA	QIANLIMA	02-10	4 SP FWD	L4 1.4L
KIA	RIO	05-16	4 SP FWD	L4 1.4L 1.6L
KIA	SHUMA	00-01	4 SP FWD	L4 1.5L 1.8L
KIA	SPECTRA	00-04	4 SP FWD	L4 1.5L 1.8L
Zhonghua	FSV	13-15	4 SP FWD	L4 1.5L
Zhonghua	JUNJIE	12	4 SP FWD	L4 1.6L

How to repair this transmission (Videos)

A4AF3 With Code P0734

Instruction manuals and useful links

Link type	Source	Description
pdf	Atra	A4BF2/A4AF3 Problems Before and After Rebuild
pdf	automaticchoice.com	Scheme A4AF3

A4CF1 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed modern automatic transmission A4CF1 produced in 2005 and its more powerful modification A4CF2 from Hyundai were designed for cars with the engine capacity up to 2 liters. Since 2006, these automatic transmissions can be installed on all FWD small cars of Hyundai (Accent, Solaris, Ceed, Getz...) and Kia (Spectra, Forte, Cerato, Soul...).

The first modification A4CF1 had a lot of problems, therefore an updated modification named A4CF2 was released in 2005. Minor changes in electrical parts and computer settings were introduced in 2007 in order to prolong the transmission lifespan that may be comparable with the resource of the whole car.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	160	6	3	SP-III

Technical issues and repair guidelines

Typical problems during the first years of the transmission operation are related to change of ATF and filter replacement. It is recommended to replace all friction components together with the kit of gaskets and seals during the transmission rebuilding.

Common problems in A4CF2-\1:

The list of the most popular repair procedures for this transmission includes the valve body reassembly and replacement of solenoids. The most vulnerable failure-prone are VFS (EPC) solenoids and PWM solenoids. The problem is related to contaminated and hot (because of the torque converter) transmission fluid and resource wear-out. In many cases problems with electrical parts are caused by faulty wiring of solenoids.

Some problems may occur in the pump as a result of a long-time operation with the leaking seal, damaged bushing (applicable to A5HF1) and shaft vibrations.Specialists assume, that high temperatures and forced torque converter lock-up lead to rapid oil contamination and this suspended fluid clogs and wears out channels in the valve body and solenoids, leading to the oil pressure shortage in packages and early burning of friction components. A long-time operation with the pressure shortage and vibrating clutch lock-up leads to problems with the pump and some other unpredictable issues.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Hyundai	AVANTE HD/MD	06-12	4 SP FWD	L4 1.6L 2.0L
KIA	CEE'D	07-11	4 SP FWD	L4 1.6L 2.0L
KIA	CERATO	05-10	4 SP FWD	L4 1.6L 2.0L

How to repair this transmission (Videos)

A4CF1/A4CF2 valve body removal

A4CF2 Multiple solenoid codes

A4CF2 Shift Problems

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme A4CF1 A4CF2
pdf	www.at-manuals.com	Valve body valves A4CF1 A4CF2
web	www.at-manuals.com	Solenoid application chart A4CF1 A4CF2
web	www.at-manuals.com	Hydraulic pressure table A4CF1 A4CF2
web	www.at-manuals.com	Clutch application A4CF1 A4CF2
pdf	Sonnax	Valve Body Layout A4CF1

A340 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The range of 4-speed of automatic transmissions А340 (also known as AW30-40LE /-70LE according to Aisin classification) has been on the market since 1985 on RWD and 4WD Toyota Land Cruiser with the engine capacity from 2.5 up to 4 liters. The А340 unit is a middle class transmission which stands next to the range А40 of the class "mini".Toyota used the А340 series for all other powerful cars: Pickup, 4-Runner, Mark II, Hilux, Hiace, Previa, etc.There is a large number of modifications of А340 Series for engines with 2.5-3.2 liters capacity.The AW30-41 modification and 30-43 is still in demand as not expensive, low-maintenance, robust gearbox for "work horse" cars.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	300	11	4	Toyota T-IV

Technical issues and repair guidelines

Each modification in this transmission family had some updates in the electrical part (linear solenoids) of the valve body and torque converter.This transmission is quite simple, balanced and has a huge resource reserve. The repair of this gearbox usually takes place in cars with high mileage and includes replacement of worn-out spare parts. It is almost always the case that the torque converter of this transmission is handed in for repair. Operating with the worn-out lockup leads to the output shaft beating and excessive side load on the pump, seal, and bushing.

Operation of the A340-equipped car with contaminated fluid results in wear-out of bushings through which the oil leaks out leading to main pressure losses. Almost all bushings are replaced together with rings and gaskets included in the repair kit. Firstly, the pump bushing gets out of service. Because of damaged bushings the pump may have performance efficiency problems leading to the oil pressure shortage in packages, therefore friction components of packages primarily involved in operation start slipping and get burnt.Commonly, frictions (with steel discs) of Forward package get burnt. The brake band is standard for all modifications. It is replaced when the car comes to repair with burnt fluid. The replacement of solenoids is common for old cars (produced before 1998).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
KIA	PREGIO	00-03	4 SP RWD	L4 3.0L

How to repair this transmission (Videos)

A340E Teardown

340E Mistake

AW4 TRANSMISSION TEARDOWN

A340 Valvebody Installation Instructions

Basic Hydraulic Operation

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme A340
web	www.at-manuals.com	Solenoid identification A340
web	www.at-manuals.com	Solenoid/component application chart A340
web	www.at-manuals.com	Clutch application A340
pdf	Sonnax	Valve Body Layout A340E, A340F
pdf	drive.google.com	A340E Service information
web	Sonnax	Toyota A340E/F Identification Guide

8HP45 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The automatic transmission ZF8HP45 with the longitudinal arrangement was manufactured as an updated version of automatic transmissions ZF6HP21, ZF6HP32.

The pilot prototype was designed in 2008 and after a short run-in on the BMW of 7-th series, ZF8HP became widely used on vehicles with a maximum torque of 450 Nm for gasoline engines (ZF8HP45) and 700 Nm for ZF8HP70 for BMW diesel engines. According to the abovementioned data, the numbers 45 and 70 in the name of the automatic transmission mean the index of maximum torque sent by the transmission.

In subsequent years ZF increased its range of automatic transmissions related to this family from ZF8HP23 for the class "mini" with 1.6 engines to ZF8HP90 for cars with engine capacity equal to 6-liters. Achievements of these automatic transmissions exceeded all expectations and resulted in a lot of praising responses, and childhood illnesses were extremely quickly corrected, unnoticed for the repair of automatic transmissions.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
8	AT	RWD/AWD	500	9	6	BMW 222305397

Technical issues and repair guidelines

For the present these unique transmissions appear in services with the purpose of the oil and filter change.The oil change should be performed in special services where it is also recommended to check the oil level and transparency of the old oil. This transmission is very sensitive to the oil quality, because more than a half of components in this transmission is made of aluminum.The torque converter repair is included in the list of mandatory procedures during ZF8HP transmissions reassembly after travelling 200-300 thousand kilometers.In case of aggressive driving behavior it is advisable to test the torque converter concerning wear-out of the clutch locks and signs of vibrations after 100 thousand kilometers. The oil should be regularly tested for transparency and presence of inclusions.

The first overhaul of 8HP transmissions with burned oil require not only repair of the torque converter but also change of all friction clutches.The most popular spare parts for 6НР transmission as well as for its predecessor are the valve body separator plate made of metal with rubber-covered tracks.Another issue is related to Mechatronics with solenoids which get burned in the summer time traffic jams because of overheating oil of worn-out torque converter lock-up and metal dust falling on magnetic detectors.One of the soft spots turns out to be the aluminum of E clutch – damage of splines: Wheel-hub, HUB "E" Clutch".The repair process also may include the Planetary gear P3 replacement (by 3 satellites for 8HP45 transmission).

It is suggested that the main issue of ZF transmissions related to the solenoid-electro-regulators VFS strong dependency on the oil flow velocity, oil contamination and dust settling inside solenoids that lead to solenoids malfunction resulting in wrong pressure parameters which differ from figures expected by the computer. Conflicts with the computer adjusting to the abovementioned circumstances lead to various unpredictable problems like clutches slippery, pushes and kicks.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Alfa-Romeo	169	16	8 SP R/4WD	L4 2.0L 2.2L
Alfa-Romeo	GIULIA	15-16	8 SP R/4WD	L4 1.4L 2.0L 2.2L V6 3.0L
Audi	Q7	10-11	8 SP R/4WD	V6 3.6L
BMW	1-SERIES	11-16	8 SP R/4WD	L4 1.6L 2.0L L6 3.0L
BMW	2-SERIES	13-16	8 SP R/4WD	L4 2.0L L6 3.0L
BMW	3-SERIES	11-16	8 SP R/4WD	L4 1.6L 2.0L L6 3.0L
BMW	3-SERIES GT	13-16	8 SP R/4WD	L4 2.0L L6 3.0L
BMW	4-SERIES	13-16	8 SP R/4WD	L4 2.0L L6 3.0L
BMW	4-SERIES GRAN COUPE	14-16	8 SP R/4WD	L4 2.0L L6 3.0L
BMW	5-SERIES	10-16	8 SP R/4WD	L4 1.6L 2.0L L6 2.5L 3.0L
BMW	5-SERIES GT	09-16	8 SP R/4WD	L4 2.0L L6 3.0L
BMW	6-SERIES GRAN COUPE	12-16	8 SP RWD	L6 3.0L
BMW	7-SERIES	10-15	8 SP R/4WD	L6 3.0L
BMW	X1	11-16	8 SP R/4WD	L4 1.6L 2.0L L6 3.0L
BMW	X3	10-16	8 SP R/4WD	L4 1.6L 2.0L L6 3.0L
BMW	X4	14-16	8 SP 4WD	L4 2.0L
BMW	X5	13-16	8 SP R/4WD	L4 2.0L L6 3.0L
BMW	X6	10-14	8 SP 4WD	L6 3.0L
BMW	Z4	11-16	8 SP RWD	L4 2.0L
Chrysler	300	11-16	8 SP R/4WD	V6 3.0L 3.6L
Dodge	CHALLENGER	14-16	8 SP RWD	V6 3.6L V8 5.7L 6.4L
Dodge	CHARGER	12-16	8 SP R/4WD	V6 3.6L
Dodge	DURANGO	12-16	8 SP R/4WD	V6 3.6L
Dodge	PICKUP/RAM 1500	12-16	8 SP R/4WD	V6 3.6L
Jaguar	F-TYPE	15-16	8 SP RWD	L4 2.0L
Jaguar	XE	15-16	8 SP R/4WD	L4 2.0L V6 3.0L V8 5.0L
Jaguar	XF	15-16	8 SP RWD	L4 2.0L
JEEP	GRAND CHEROKEE	11-16	8 SP R/4WD	V6 3.0L 3.6L
JEEP	WRANGLER UNLIMITED	15-16	8 SP 4WD	V6 3.6L
Lancia	THESIS	11	8 SP R/4WD	L4 1.8L L5 2.5L V6 3.6L
Land-Rover	DISCOVERY(LR3)	10-11	8 SP R/4WD	L6 3.7L
Volkswagen	AMAROK	12-16	8 SP R/4WD	L4 2.0L V6 3.6L

How to repair this transmission (Videos)

Components and operation

Valve Body

ZF8HP70 Main Case

ZF8HP70 Pump Removal

ATSG Transmission Tip

Ray's Garage- ZF8HP70 Unit Disassembly

Ray's Garage Tech Tip: ZF8HP55

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout ZF8HP45, ZF8HP70
pdf	Sonnax	Valve Body Layout ZF8HP55
pdf	Sonnax	Vacuum test ZF8HP45, ZF8HP70

722.9 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 7-speed automatic transmission Mercedes 722.9 was produced in 2004 (G-tronic) and considered to be a masterpiece from Mercedes Benz for С-class models. It was used for all RWD Mercedes cars from С180 to С350. This transmission was designed on constructive basis of the 6-th series of automatic transmissions and many spare parts are interchangeable.

W7X550 - for engines up to 3,5L and 550Nm; ATF capacity - 8,6L;
W7A700 - for engines up to 5,5L and 700Nm; ATF capacity - 8,9L;
W7B700 - for engines up to 6,3L and 850Nm; ATF capacity - 9,1L.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
7	AT	RWD/AWD	550-850	9,1	5	236.15

Technical issues and repair guidelines

For this transmission, Mercedes engineers used the controlled slipping of the of the torque converter frictions, which starts from the first gear. In many cases, this peculiarity leads to rapid fluid contamination by the torque converter frictions and premature necessity for fluid change and the torque converter rebuilding.

The whole family of 722.9 transmissions is sensitive to issues with fluid shortages and its contamination. The main spare parts in this transmission are wearable teflon rings, which are crucial for accurate gear shifting. There are two types of friction components for this gearbox- one-sided and two-sided.In most cases, frictions of the K2 package get replaced. The K1 frictions are replaced less often as well as K3 frictions, but repair specialists order a full kit of friction discs in case of burnt oil.

The first typical problem of the 9th series is related to the failure of the connector electronic board - the sensor Y3 / 8n1 gets burnt. In most cases, this board is replaced. The resource of solenoids heavily depends on the oil contamination level and leakproofness of packages.The second common problem of this transmission is the damage of the housing bell caused by vibrations from aggressive driving.

The valve body in this transmission operates at temperatures up to 130º and it is very sensitive to overheated and contaminated fluid and shavings. Small springs of the valve body can break down, solenoids may get clogged. Experts assume that abnormal operation of the valve body leads to shortages of oil pressure in the 722.9 unit, frictions get burnt and other problems occur in the chain order. Since Mercedes engineers provided the valve body repair without the transmission removal, thus it is possible to detect the abovementioned problem and solve it by means of reassembly and cleaning.

Problems also occur in the multi-function switch (Servo mechanism module). Although components of this transmission are quite reliable, but problems in the electrical part have a negative impact on the oil pump and consequently result in issues with the rear planetary gear and bushings.The torque converter repair is one more operation which should become a preventive measure to prolong the service life of this transmission.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercedes-Benz	CLC	08-11	7 SP RWD	V6 2.5L 3.5L
Mercedes-Benz	CLK	04-09	7 SP RWD	V6 2.5L 3.0L 3.5L V8 5.0L 5.5L 6.3L

How to repair this transmission (Videos)

722.9 Teardown Inspection

722.9 Valvebody Overhaul

(TCM) repair part 1

(TCM) repair part 2

Transmission, pump damage

722.9 TCC adaption

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Diagnosis, Repair Advanced Training 722.9
web	www.at-manuals.com	Electrohydraulic control module 722.9
web	www.at-manuals.com	Solenoid and electronic control identification 722.9
web	www.at-manuals.com	CheckBalls 722.9
web	www.at-manuals.com	Solenoids work 722.9
web	www.at-manuals.com	Scheme 722.9
pdf	Sonnax	Valve Body Layout 722.9
web	mercedesmedic.com	722.9 7G Tronic Automatic Transmission Problems and Solutions

722.6 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed Mercedes automatic transmission 722.6 was to supposed to be an ideal transmission for flawless cars. It was installed on Mercedes, Porsche 911, Jaguars, Jeeps and many other RWD models with the engine capacity from 3 to 6 liters.This unique transmission was duly appreciated on the market, and was selected for many exclusive cars. For many years, this unit was by American (Chrysler, Jeep, Dodge), and European(Porsche, Jaguar, ...) automakers.

W5A330 - up to 3,5L engines 350Nm, full capacity 8,7L ATF;
W5J400 - up to 4,3L engines 420Nm, full capacity 9,1L ATF;
W5A580 - up to 6,0L engines 580Nm, full capacity 9,3L ATF.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD	350, 420, 580	9,5	4	236.14

Technical issues and repair guidelines

Many experts assume that this transmission has its design peculiarities which require some skills from repair specialists. This transmission is maintenance-friendly, it has a huge resource for transmission components and can serve for a long time, when following the rules of operation and visit a repair shop for well-timed overhaul and replacement of repair parts.

In many cases, repair specialists have to fix the torque converter and replace rubber and plastic spare parts. In most cases, technicians have to replace all friction elements, even if they haven't exhausted their resource.

The electric board with speed sensors get out of order because of regular overheating and contaminated ATF. Operating with the faulty valve body and electrics leads to general oil starvation, wear-out of bushings, vibrations and wear of other units of 722.6 series. Separators of rear and front overrunning clutches are frequently replaced in the process of repair services.If the transmission is used with a worn-out torque converter for a long time, then vibrations and metal debris damage not only bushings, but also friction surfaces of the pump cover. In this case, masters replace the pump cover with gears. Frequently, it is required to replace a rear bushing of the K2 drum, which is damaged by vibrations from unevenly wornout frictions.

The repair of the 722.6 torque converter is one of the most demanded and highly-priced procedures because of the transmission complex design and record number of spare parts. The operation of the 6th series automatic transmissions with the faulty torque converter has a negative impact on the valve body. Therefore, it is recommended not only to completely change ATF, but also hand in the torque converter for replacement of the friction coupling.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercedes-Benz	VANEO	01-05	5 SP FWD	L4 1.7L 1.9L

How to repair this transmission (Videos)

Teardown Inspection

Teardown inspection Part 2

Bellhousing Swap & Reassembly

Valvebody overhaul

B2-B3 Clutch Drum Assembly

4Matic Quick Tip

NAG1 5-Speed Transmission Power Flow

Plate Diagnose

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Scheme
web	www.at-manuals.com	Valve Body 722.6
web	www.at-manuals.com	Solenoids 722.6 transmission
web	www.at-manuals.com	Identify type of 722.6 transmission p1
web	www.at-manuals.com	Identify type of 722.6 transmission p2
pdf	Sonnax	Valve Body Layout 722.6
pdf	Sonnax	Vacuum test 722.6/CHRYSLER NAG 1

722.5 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission 722.5 had been used on rear- and four-wheel drive vehicles (Gelendwagen) from 1990 to 1997. The 722.5 design is based on successful 4-speed solution 722.3. The construction of the 3-rd series is complemented with advanced electronic control and the clutch package Overdrive. Almost all componentsin the 722.5 unit are interchangeable with 722.3. All typical problems are also identical.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD	580	8,5	4	236.14

Technical issues and repair guidelines

The repair kit of gaskets and seals is ordered for reassembly of 722.5. In addition to typical overhaul procedures for this transmissions (replacement of gaskets and seals), repair specialists also replace the oil filter. The overhaul certainly includes repair of the torque converter caused by wear-out of friction linings of actively operating lock-up clutch (leaking pump seal is the sign of wear-out). In many cases, the repair consists of replacement of current pump seal and the pump bushing.

Transmission specialists also frequently have to replace all friction components. The package Reverse (piston) is replaced quite often because of damaged springs (because of old age) which are harmful for the whole unit.

The electrical part in the 722.5 unit (as well as hard parts) is quite reliable and its service life is compatible to the car's lifespan. Automatic transmission of 5-th series endures harsh operation conditions without any serious problems in contrast to following generations of 5- and 7-speed automatic transmissions 722.6 and 722.9.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercedes-Benz	300SL	90-93	5 SP RWD	L6 3.0L
Mercedes-Benz	S CLASS	94-95	5 SP RWD	L6 3.2L

How to repair this transmission (Videos)

722.5 Mercedes Transmission

722.5 Valvebody Overhaul

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Scheme

722.3 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The family of 4-speed automatic transmissions Mercedes 722.3 - 722.4 has been used since 1981 on all popular RWD Mercedes models with engine capacities from 2.3 up to 5 liters, which operate for decades.

The difference between series 722.3 (W4A40) and 722.4 (W4A20) is externally indeterminate, because both gearboxes operate flawlessly. Before 1997 almost all components for 722.3 and 722.4 had been interchangeable, apart from difference in gaskets and frictions. The 5-th series is practically identical to the 722.3.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	570	8,6	4	236.12

Technical issues and repair guidelines

A typical kit for the 722.3 transmission reassembly includes Overhaul kit (repair kit of gaskets and seals), which differs for 722.3, 4-th and 5-th series. The torque converter usually gets in repair services in the process of transmission reassembly.

Old transmissions often have problems with the Reverse package , where springs get damaged causing problems for following components:

- Damper cone ring (B-3 / Reverse Clutch) for 722.4.

- Spring with the holder ОЕМ№...993-2702,

- Piston

The most frequently bought part for repair is the brake band.It is also required to replace the pump cup in all vehicles which went through oil starvation or the torque converter hub overheating (caused by usage of the worn-out torque converter). The electrical part of this transmission is so simple and reliable that in rare cases repair specialists have to replace kick-down solenoid.The only problem of the valve body is the dirt, which clogs channels. With time transmission specialists have to replace plunger springs. Valve bodies are mainly repaired and cleaned, spare parts usually don’t get replaced.

All problems of these reliable transmission are related to ATF shortages, contaminated ATF, overheated ATF because of clogged radiator and defective torque converter. If the ATF change is well-timed and the radiator stays more or less clean in-and-out, then these transmissions can operate without the overhaul over 300 thousand kilometers. The only required preventive repair is replacement of the torque converter spare parts. If the vehicle equipped with this transmission travels over 200 thousand kilometers, then it’s a high time to perform the abovementioned torque converter repair procedure.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercedes-Benz	400	92-93	4 SP RWD	V8 4.2L
Mercedes-Benz	500	90-93	4 SP RWD	V8 5.0L
Mercedes-Benz	S CLASS	94-95	4 SP RWD	L6 3.4L V8 4.2L 5.0L

How to repair this transmission (Videos)

722.424 Transmission Rebuild

722.424 Teardown

722 4 Pressure Control cable connection

722 424 Valve Body Rebuild

722.3 Valve Body Rebuild

722.3 K2 Drum Overhaul

B1 Piston Cap Tool

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme
pdf	www.at-manuals.com	TransTec Manual
web	www.at-manuals.com	Application chart
pdf	jenniskens	Transmission Adjustment Guide

6DCT450 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The main constructive idea for shifting gears in DCT WD is adopted from n-speed transmissions and the shifting is performed by means of hydraulics and solenoids controlled by the control unit. Therefore many age-related problems are the same as n-speed transmissions: metal friction suspended material from hot ATF clogs valves of the valve body and solenoids, gets on the rubbing surfaces and promotes the wear of aluminum by vibrations and sticking of valves, especially when the friction clutches are worn out, that leads to a chain reaction of metal wear and further contamination of oil.

Therefore the 6DCT450 has more capacious outside filter in comparison with other CVTs. There are several filters-cartridges modifications, which are different for DCT450 and DCT470. The filter is included in the overhaul repair kit, but Gertrag engineers recommend to replace this filter more often, especially if the transmission has been used for a long time.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	DCT	FWD	450	1,8	1,8	75w90

Technical issues and repair guidelines

For the DCT450 transmission reassembly, specialists order the repair kit of gaskets and seals. Repair kits contain gaskets (required as a minimum), which affect the operation of this delicately adjusted transmission. The wearout of Teflon rings also has a major impact on the transmission operation. Replacement of the filter with ATF is a typical repair procedure recommended for maintenance of WD Powershift transmissions. It is advisable to change oil more often and not later than after 45-50 thousand kilometers.

For the overhaul of 6DCT450 it is common to replace solenoids in order to solve problems with the valve body. The overhaul of the clutch basket in 6DCT450 is accompanied by order of springs and retainers-clips. When the dry clutch gets out of order specialists have to replace the step motor or more frequently the transmission itself

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	C-COUPE	11	6 SP FWD	L4 2.0L
Ford	C-MAX	11-16	6 SP FWD	L4 2.0L
Ford	ESCAPE	12-16	6 SP 4WD	L4 2.0L
Ford	FOCUS	06-16	6 SP FWD	L4 1.5L 2.0L
Ford	GALAXY	10-15	6 SP FWD	L4 2.0L 2.2L
Ford	MONDEO	08-15	6 SP FWD	L4 1.6L 1.8L 2.0L 2.2L
Ford	S-MAX	10-15	6 SP FWD	L4 2.0L

How to repair this transmission (Videos)

Learning The Getrag's DCT450

Hard Parts Identification Video

Disassemble clutch

Disassembly and measurement of clutch components

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme 6DCT450
pdf	www.getrag.com	Specifications 6DCT451
pdf	drive.google.com	Repair manual 6DCT450

62TE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 62TE is a 6-speed automatic transmission produced in 2006 as the part of АТ family Chrysler "UltraDrive". The FWD 4-speed A604 (41TE) is taken as a base model for 62TE in terms of design. The 62TE is produced for FWD cars Chrysler with the engine up to 4-liters (sedans Sebring, crossovers Pacifica, and minivans Town & Country, Voyager and Caravan from Dodge).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD		8,5	5,2	Mopar ATF+4

Technical issues and repair guidelines

Repair procedures and typical problems

Repair kits for the 62TE transmission include the following:

- Repair kit of gaskets and seals

-Kit of friction components

-Kit of steel discs

A standard set for reassembly of the automatic transmission with burnt friction elements includes the kit of pistons (6 pieces).The block of solenoids, separately installed solenoid EPC and sensor EPC serve as a typical spare part for these transmissions when the car runs 200 thousand kilometers.

EPS solenoids and solenoid of the torque converter clutch lock-up are the first to wear out in the valve body. Solenoids are replaced together with worn-out rings and gaskets in order to avoid early overloading of these delicately adjusted electric regulators.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chrysler	200	06-14	6 SP FWD	V6 2.7L 3.5L 3.6L
Chrysler	200	10-14	6 SP FWD	L4 2.4L
Chrysler	PACIFICA	07-08	6 SP F/4WD	V6 4.0L
Chrysler	SEBRING/SEBRING CONVERTIBLE	06-12	6 SP FWD	L4 2.4L V6 2.7L 3.5L
Chrysler	TOWN & COUNTRY	07-16	6 SP FWD	L4 2.8L V6 3.6L 3.8L 4.0L
Chrysler	VOYAGER	07-08	6 SP FWD	L4 2.8L
Dodge	AVENGER	07-14	6 SP FWD	V6 2.7L 3.5L 3.6L
Dodge	AVENGER	10-14	6 SP FWD	L4 2.4L
Dodge	CARAVAN	07-16	6 SP FWD	L4 2.8L V6 3.3L 3.6L 3.8L 4.0L
Dodge	CARGO VAN	11-15	6 SP FWD	V6 3.6L
Dodge	JOURNEY	08-16	6 SP F/4WD	L4 2.4L V6 2.7L 3.5L 3.6L
Dodge	PROMASTER	13-16	6 SP FWD	V6 3.6L
Fiat	FREEMONT	11-16	6 SP F/4WD	L4 2.0L 2.4L V6 3.6L
Lancia	MPV	11-12	6 SP FWD	L4 2.8L V6 3.6L
Volkswagen	ROUTAN	08-13	6 SP F/4WD	V6 3.6L 3.8L 4.0L

How to repair this transmission (Videos)

62TE Final assembly

62TE Teardown

2TE Valvebody Overhaul

62TE Updates

Solenoid Pack Pin ID

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Scheme 62TE
pdf	www.at-manuals.com	Catalog 62TE

5R55N Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission 5R55N (5R55W, 5R55S) was released in 2000 and found application in Ford Explorer and THUNDERBIRD. Besides Ford and Lincoln, it was installed on Mazda pickup trucks in Asia and on Jaguar S-type (for 2 years). In 2002, the problematic 5R55N was replaced by a new sub-modification 5R55W, and in 2003 the 5R55S was released with some updates. This transmission is installed on RWD and 4WD vehicles with quite powerful engines (from 3 up to 5 liters). In terms of design, this transmission belongs to the 4R44 - 4R55E family .

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD		11,5	5	MerconV

Technical issues and repair guidelines

The design of this transmission includes a forced electronic control of the torque converter lock-up. It complicates the system operation and makes it dependable on the ATF quality. The torque converter of the automatic transmission clogs the valve body quite rapidly and turns out to be the main reason of the valve body contamination and failure of the solenoids.

During the first years of operation, it is required to monitor possible leakages (quantity and quality of oil MerconV - 11.5 liters) and the filter condition. The 5R55N is very sensitive to contaminated ATF and the torque converter repair is the first in the list of rebuilding procedures.

The most common repair procedure is replacement of the filter and the pan gasket. There are 3 modifications of filters depending on the pan dimensions and year of manufacture.In addition to spare parts, it is frequently required to replace brake bands (Intermediate - O.Drive). One more constructive problem is the failure of the band locking plate caused by sidesway and vibrations. They are replaced together with the servo piston.In many cases, sensors of the output\input shaft speed (VSS\ISS) also get replaced.

In most cases, friction components of the Forward package get burnt, but specialists replace not only a full kit of friction discs, but also steel discs and the bearing disc of this package.The pump valve is the most vulnerable element in the pump. Sticking of the valve leads to delays in gear shifting or even to the lack of the pull-rod at growing engine revs.

The valve body is repaired quite often, therefore Sonnax released many repair kits for rebuilding of these transmissions. This problem is common for all valve bodies produced in the early 2000s, in which the torque converter locking was performed too early and accompanied by strong slippage. It is complicated by the fact that drivers in these situations too often use aggressive accelerations and too rarely changed ATF and the torque converter friction elements.

It is recommended to install additional cooling radiator on “old” cars, which went through the ATF overheating and burning of friction elements.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	THUNDERBIRD	2	5 SP RWD	V8 3.9L
Jaguar	S TYPE	00-02	5 SP RWD	V8 4.0L
Lincoln	LS	00-02	5 SP RWD	V6 3.0L V8 3.9L

How to repair this transmission (Videos)

5R55S - Repair - Part - 1

5R55S - Repair - Part - 2

5R55N Valvebody Quick tip & Repair

5R55S Valve Body

Teardown with code P0775

5R55S Servo Bore Repair

5R55W Servo Bore Repair

5R55W TEAR DOWN

5R55W SERVO BUSHING INSTALL

5R55W SUBASSEMBLY

Instruction manuals and useful links

Link type	Source	Description
pdf	www.valvebodypros.com	Initial Engagements
pdf	www.at-manuals.com	Repair manual 5R55W, 5R55S
pdf	Sonnax	Valve Body Layout 5R55N
pdf	Sonnax	Valve Body Layout 5R55S, 5R55W
web	Sonnax	Check Balls 5R55W/S

5R55E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5R55E is an automatic gearbox produced by Ford. It is the five-speed automatic transmission, which was widely applied in both two and all-wheel drive cars. This transmission found application in various Ford models (such as Lincoln and Mercury).

Regarding the mechanical part, the 5R55E is similar to the 4-speed 4R55E. The 5R55E has the adaptive shift control and directional high energy frictions. It was the 1-st five-speed electronically-controlled gearbox in an American car.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD		9	3	Dexron VI

Common issues:

1)Malfunction of solenoids – this transmission employs solenoids to control many of its functions, including the gear shifting process and operation of the torque converter lock-up. The simplest and method of testing solenoids is to use the ohm meter, which measures solenoids resistance.

2)High chance of overheating: like any other automatic gearbox, the 5R55E is subject to overheating, especially if it is exposed to severe operation conditions. Overheating frequently leads to the transmission failure, therefore transmission repair specialists often recommend installing transmission coolers, which help to cool down the transmission.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	AEROSTAR	97	5 SP R/4WD	V6 4.0L
Ford	EXPLORER/SPORT TRAC	97-08	5 SP R/4WD	V6 4.0L
Ford	RANGER	97-11	5 SP R/4WD	L4 2.3L V6 3.0L 4.0L
Mazda	PICKUP B SERIES	97-10	5 SP R/4WD	V6 4.0L
Mercury	MOUNTAINEER	98-00	4 SP R/4WD	V6 4.0L

How to repair this transmission (Videos)

5R55E Teardown

5R55E transmission P0733 3rd. Incorrect gear ratio

5R55E Valve Body Shift Kit Installation

INSTALLATION PROBLEM PART 1 OF 3

INSTALLATION PROBLEM PART 2 OF 3

INSTALLATION PROBLEM PART 3 OF 3

Instruction manuals and useful links

Link type	Source	Description
pdf	Atra	2-3 Flare in the 5R55E
pdf	drive.google.com	Repair manual 5R55E

5R110W Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission 5R110W was released in 2003. This transmission was mainly intended for all-wheel drive pick-ups and powerful off-road vehicles produced by Ford. This transmission turned out to be quite popular. It had been produced for 10 years before being replaced by the fully automatic 6 speed transmission. The strengthened design is one of the main peculiarities of this transmission. The arrangement of drive shafts, which are positioned close to each other, allowed engineers to reduce the dimensions of 5R110W without any harm to its reliability. This gearbox is used in cars with the engine capacity up to 6 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	AWD	1100	17,7		Mercon SP

The extensive application of automatic systems positively affected user-friendliness of this transmission, but at the same time, this step had a negative impact on reliability of 5R110W.

Control units, sensors and cables of this transmission are extremely sensitive to frequent changes of temperature, and they get out of order quite early. The complexity of repair of this transmission lies in issues with diagnostics. Even with the use of special equipment, it may be quite problematic to determine the source of the problem on the first try. It complicates the repair process, and increases the cost of its implementation.

The repair and service maintenance of the 5R110W transmission is notable for its complexity and must be performed by professionals. Even ATF change cannot be performed without special equipment. Problems with the valve body are typical for this transmission. When the mileage reaches 200-250 thousand kilometers solenoids fail to function and should be replaced. In addition, transmission repair specialists often have to perform a complex procedure of cleaning oil supply channels in the valve body.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	E-SERIES	97-16	5 SP RWD	V10 6.8L V8 5.4L 6.0L
Ford	EXCURSION	03-05	5 SP R/4WD	V8 5.4L 6.0L DIESEL V10 6.8L
Ford	F-250 SUPERDUTY /F-350 SUPERDUTY	03-10	5 SP R/4WD	V8 5.4L 6.0L DIESEL 6.4L V10 6.8L
Ford	F-450/550 SUPER DUTY	03-08	5 SP R/4WD	V8 6.0L DIESEL

How to repair this transmission (Videos)

(TorqShift)Transmission Teardown Inspection

(TorqueShift) Transmission Part 2

Transmission Teardown Ford 5R110W

Vacuum Testing - 5R110W

18:03 5 вещей которые НИКОГДА нельзя делать на АКПП (автоматической коробке передач). JoRick Revazov Рекомендуемые вам 1:02:16 5R110 rebuild (reassembly ) western truck and tractor repair 3,9 тыс. просмотра 36:10 5R110W Teardown Gary Ferraro 1,2 ты

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Scheme 5R110W
web	Sonnax	6 Key Features to Understand in Ford E4OD, 4R100 & 5R110W TC

5L40E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission 5L40E was designed in 1999 jointly with the 4-speed 4L40E. It became widely used on RWD vehicles of GM and BMW with engines from 2.0 up to 3.6 liters (340 Nm) since 2000. This transmission was especially preferred by BMW (from BMW 3 (4L40E) to BMW 5 and Х5 (5L40E). Then these transmissions were commonly used across the globe: the USA (BMW, Opel, ...), China and Australia (Saturn, Cadillac etc.) and for Land Rover and Cadillac in the UK. The 5L40E transmission is designed on structural basis of 4L60E tested on American roads and produced on GM plant in Strasbourg, France.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD	420	9	6	Texaco ETL-7045 E / Dexron VI

Technical issues and repair guidelines

One of typical problems for the 5L40E during the first years of production is the radiator temperature regulator failure resulting in problems with the torque converter. The torque converter is handed in for repair during the reassembly. Experts assume that the torque converter cannot endure frequent forced switch-on of the clutch lock-up, its friction lining burns faster than other friction elements leading to dirt accumulation in the pump, valve body and solenoids and consequently all other transmission units.

Friction elements of the pack (Direct) (one-sided with internal and external teeth) burn twice as often as the Forward pack. Cover plates of the Direct pack are commonly replaced together with clutches. O.Dr.; Reverse frictions also get burnt quite often.The tight fit of rubber covered pistons is an unpleasant peculiarity of 5L40E repair, caused by features of the rotor type oil pump with its huge pressure potential.The kit of rubber-covered pistons is usually ordered for the overhaul.

PMW solenoids rapidly wear out instead of the valve body channels and plungers.Problems with solenoids which exhausted their resource and dirty valve body lead to insufficient pressure in the line that may result in ATF overheating because of slipping frictions, vibrations caused by uneven wear-out and cranking by bushes.

The kit of bushings is a typical order for repair of the 5L40E, which went through a long-time oil starvation at high speeds. One of the most common problems is the pump stator channel wear-out leading to the oil pressure decrease. The pump stator valve is also replaced quite often.

The valve body primarily suffers because of modes settings, when PWM-solenoids open the channel for ATF not immediately on full cross-section, but step-by-step opening and closing it. Movement acceleration of a hot pulp occurs in the narrowest area because of ATF and dirt. The torque converter transmits dirt to the transmission by means of worn-out clutch of the valve lock-up. Solenoids and the oil pump reach the end of their service life earlier than the valve body. It is a trigger for car owners to change oil and solenoids avoiding the valve body wear-out.

The 5L40E is considered to be a robust and reliable transmission, when preserving it from heavy oil contamination with friction dust, which wears transmission components.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Cadillac	SRX	03-10	5 SP R/4WD	V6 3.6L V8 4.6L
Cadillac	STS	04-09	5 SP R/4WD	V6 2.8L 3.6L V8 4.6L

How to repair this transmission (Videos)

Pump Overhaul

Initial Findings

Shift Solenoid Reconditioning

Torque Converter Inspection

Cone set

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme 5L40
web	www.at-manuals.com	Check Balls 5L40e
web	www.at-manuals.com	Solenoid application chart 5L40e
pdf	Sonnax	Valve Body Layout 5L40-E
web	Sonnax	5L40E/5L50-E Loss of Reverse or TCC

5HP24 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission ZF 5HP24 was designed for powerful 6 and 8-cylinder engines (diesel and 2.4 - 4.5 liter IC-engines) in AWD and RWD high-priced Audi and BMW models (5-th and 7-th series Х5...). It is an intermediate transmission unit between famous 5HP19 and powerful 5HP30. It had been used since 1995 up to 2005.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD/FWD	440	9,7	4-5	LT -71141

Technical issues and repair guidelines

If this transmission is handed in for repair, transmission specialists have to change ATF, replace not only filter and numerous spare parts, but also the input drum of the clutch package А, which has problems with a circlip. In most cases, the input drum of the clutch package А is rebuilt rather than replaced with a new one. The whole kit of frictions is replaced in case of burnt oil.

In terms of design, the whole package А is considered to be a weak spot. The number of friction components and their diameters were increased several times in the process of manufacture, but still this package is the first to get burnt when transmitted torque reaches the maximum.

The second typical problem of this transmission (in addition to the drum А replacement) is the hub bearing (В). Vibrations caused by overloads damage the bearing and then the hub. One of the main causes for this problem is related to fluid shortages. Almost each overhaul (if the overhaul kit is not ordered) involves replacement of seals. Another typical problem for “old” 5HP24 is the one-way clutch F.

Old and overheated cars (older than 10 years) often require replacement of wiring in solenoids.Solenoids are the main spare parts among electrical components of this transmission. The torque converter is a separate issue of automatic transmission.The torque converter is considered to be the soft spot for transmissions of powerful vehicles, but in case with this transmission this problem is especially vivid. The 5HP24 unit is the second transmission among the most frequently repaired ZF transmissions. This transmission is also included in the world top 5 transmissions for overhaul coming after 5L40 and Audi 01P/N/M family.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
BMW	5-SERIES	96-04	5 SP RWD	L4 2.0L L6 2.2L 2.5L
BMW	7-SERIES	01-02	5 SP RWD	L6 3.0L
Jaguar	VANDEN PLAS	98-02	5 SP RWD	V8 4.0L
Jaguar	XJ8	98-03	5 SP RWD	V8 3.2L 4.0L
Jaguar	XK8	97-02	5 SP RWD	V8 4.0L

How to repair this transmission (Videos)

ZF5HP24 Teardown

ZF5HP24 Transmission common problems

Assembly Tip, A clutch Drum

Valvebody Quick Tip

Valvebody Assembly

No Reverse Hot

Broken Input Clutch Drum

Instruction manuals and useful links

Link type	Source	Description
pdf	Valve Body Pro	T-Case Problem RangeRover 5HP24
web	www.at-manuals.com	Application chart 5HP24
pdf	www.at-manuals.com	Spare parts catalog 5HP24

4T65E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed 4T65E was designed on the basis of the 4T60 transmission. In 1991, this gearbox was modified for FWD vehicles with engines (2-4 lit.). After testing, this transmission has been supplied to the market since 1993. The 4T60E was modified in 1993 and renamed as 4T65E. This gearbox is a robust product of GM, which properly operates for the first 5-7 years of service. The 440-T4 has been operating since 1983 on Cadillac named as 4T60, and considered to be quite convenient and repairable. Heavy duty (HD) modification is able to work in couple with 440 Nm engines.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD/AWD	380	12,7	7	Dexron VI

Technical issues and repair guidelines

The torque converter (TC) of 4T65E commonly causes a lot of problems during repair procedures. Bearings is a soft spot in this transmission unit. After covering 200 thousand kilometers bearings may get damaged at any moment. The major repair of this gearbox after 150-170 thousand kilometers requires replacement of all bearings.

Issues with the differential bearing may cause the most expensive difficulties (namely, damage of the sun gear differential together with differential planet gears). Then the oil flow with metal pieces may damage the valve body (VB).The main soft spots of the 4T65E frictions are two friction packages, namely, 3rd Clutch with one-sided frictions and 2nd Clutch.

In terms of design, the VB unit of the 4T60E has a lot of differences in comparison with the solution of the 4T60E. This gearbox is also sensitive to contaminated and overheated ATF as well as damaged differential.In electrical components, solenoids have quite a short service lifespan (it is advisable to check the operability of solenoids when the mileage exceeds 150 thousand kilometers).In case of an old car overhaul with mileages strongly beyond 200 thousand kilometers, it is required to replace worn-out bushings which are commonly ordered in a complete kit.

This gearbox is reliable and not complicated. After a major repair it has a substantial resource, if drivers monitor the ATF cleanness and not overload the transmission by maximum torques.Problems mainly occur in the XC90 using the differential in its design. Volvo cars with this gearbox are not intended for driving off the road as well as on muddy roads.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	CENTURY	00-04	4 SP FWD	V6 2.5L 3.0L 3.1L
Buick	CENTURY	00-04	4 SP FWD	V6 2.5L 3.0L 3.1L
Buick	LACROSSE/ALLURE	04-09	4 SP F/4WD	L4 2.4L V6 3.0L 3.6L 3.8L V8 5.3L
Buick	LESABRE	98-05	4 SP FWD	V6 3.8L
Buick	LUCERNE	05-11	4 SP FWD	V6 3.8L 3.9L
Buick	PARK AVENUE/ULTRA	97-04	4 SP FWD	V6 3.8L 3.8L SC
Buick	REGAL	97-04	4 SP FWD	V6 3.8L SC
Buick	RENDEZVOUS APV	01-06	4 SP F/4WD	V6 3.4L 3.5L 3.6L
Buick	RIVIERA	97-99	4 SP FWD	V6 3.8L
Buick	TERRAZA	05-07	4 SP F/4WD	V6 3.5L 3.9L
Chevrolet/GM	IMPALA	00-16	4 SP FWD	V6 3.4L 3.5L 3.8L 3.9L V8 5.3L
Chevrolet/GM	LUMINA	97-01	4 SP FWD	V6 3.1L 3.4L 3.8L 3.8L SC
Chevrolet/GM	MONTE CARLO	97-07	4 SP FWD	V6 3.1L 3.4L 3.5L 3.8L 3.9L 3.8L SC V8 5.3L
Chevrolet/GM	UPLANDER	03-08	4 SP F/4WD	V6 3.5L 3.9L
Chevrolet/GM	VENTURE APV	99-05	4 SP FWD	V6 3.4L
Oldsmobile	88 ROYALE	97-99	4 SP FWD	V6 3.8L 3.8L SC
Oldsmobile	AURORA	01-03	4 SP F/4WD	V6 3.5L
Oldsmobile	INTRIGUE	98-02	4 SP F/4WD	V6 3.5L 3.8L V8 4.5L
Oldsmobile	SILHOUETTE	99-04	4 SP F/4WD	V6 3.4L
Pontiac	AZTEK	01-05	4 SP F/4WD	V6 3.4L
Pontiac	BONNEVILLE	97-05	4 SP F/4WD	V6 3.8L 4.6L
Pontiac	G6	06-09	4 SP FWD	V6 3.9L
Pontiac	GRAND PRIX	97-08	4 SP F/4WD	V6 3.1L 3.8L V8 5.3L
Pontiac	MONTANA / SV6	99-08	4 SP F/4WD	V6 3.5L 3.9L
Pontiac	TRANS SPORT	99-04	4 SP F/4WD	V6 3.4L
Saturn	RELAY	05-07	4 SP F/4WD	V6 3.5L 3.9L
Volvo	S80	99-06	4 SP FWD	L6 2.9L

How to repair this transmission (Videos)

Teardown Inspection with code P1811

Transmission Teardown Inspection

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	TransTec Manual 4T65e
pdf	www.at-manuals.com	Scheme 4T65e
web	www.at-manuals.com	Check Balls 4T65e
web	www.at-manuals.com	4T60E Solenoids
pdf	Sonnax	Valve Body Layout 4T65-E
pdf	Sonnax	Vacuum test 4T65-E

4T40E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 4T40E, 4T45E rarely appears in repair services. It has been used since 1995 on FWD American (and Korean) GM vehicles with engines up to 2 liters. In terms of design, this transmission is related to the 3T40, their spare parts are interchangeable.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	230	11,7	6,5	Dexron VI

Technical issues and repair guidelines

The repair of the 4Т40 transmission often lies in change of ATF, and replacement of filter and spare parts. The oil of any type (from Dexron III to Dexron VI) may be used for the 4Т40 transmission.

The torque converter is a soft spot in almost all American automatic transmissions and requires replacement of spare parts quite early. Driving with worn torque converter may lead to vibrations, rapid ATF contamination and issues with the seal and bushing of the torque converter located immediately near the input. If this problem stays neglected, then it is required to change the torque converter bushing and the whole kit of bushings.The problem of burnt ATF is solved by replacement of all friction elements and the brake band.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	SKYLARK	97	4 SP FWD	L4 2.4L
Chevrolet/GM	CAVALIER	95-05	4 SP FWD	L4 2.2L 2.3L 2.4L
Chevrolet/GM	LACETTI	06-08	4 SP FWD	L4 1.5L 1.6L
Daewoo	NEXIA	00-03	4 SP FWD	L4 1.5L
Daewoo	NUBIRA-2	00-04	4 SP FWD	L4 1.5L 1.6L 1.8L 2.0L
Oldsmobile	ALERO	99-04	4 SP F/4WD	L4 2.2L 2.4L
Oldsmobile	CUTLASS	97-99	4 SP FWD	V6 3.1L
Pontiac	GRAND AM	99-05	4 SP FWD	L4 2.2L 2.4L
Pontiac	SUNFIRE	95-05	4 SP F/4WD	L4 2.2L 2.4L

How to repair this transmission (Videos)

4T40E Teardown

Transmission - Teardown Inspection

4R100 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 4R100\ E4OD for powerful RWD vehicles with engine capacity from 5 liters was produced by Ford since 1996.This transmission is a modification of its predecessor E4OD, which was used since 1989.It is tested, well-balanced and rare in repair transmission. Efficient and not complicated design of this transmission served as a basis for the following generation of the 5-speed automatic transmissions - 5R110W. (starting from 2003).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	1000	16,2	8	Mercon V

Technical issues and repair guidelines

Problems with this transmission start with solenoids, reaching the end of their service life, or when the valve body gets clogged together with valves, transmitting the pressure in line. It leads to the burning of friction components or even drums.Filters for both modifications 4R100\ E4OD are the same and differ by high scoop.The kit of frictions gets fully replaced in case of burnt ATF.

In addtion to spare parts with rubber covered pistons, a typical repair order includes the brake band Intermediate (Direct, High/ Reverse). Seals of the pump and the input shaft are replaced in the course of repair of old cars.

Then transmission specialists usually deal with the following components:

- the drum Intermediate/ Overdrive Clutch

- Separator of the overrunning clutch Sprag, (INTERM).

- solenoids are replaced as a whole block.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	ECONOLINE 150	1/98-04	4 SP RWD	V8 5.4L
Ford	ECONOLINE 250/250 SUPER DUTY	1/98-04	4 SP RWD	V8 5.4L 7.3L DIESEL V10 6.8L
Ford	ECONOLINE 350/350 SUPER DUTY	1/98-05	4 SP RWD	V8 5.4L 7.3L DIESEL V10 6.8L
Ford	EXCURSION	00-05	4 SP R/4WD	V8 5.4L 7.3L DIESEL V10 6.8L
Ford	EXPEDITION	1/98-02	4 SP R/4WD	V8 5.4L
Ford	F-150 /F-250	1/98-07	4 SP R/4WD	V8 5.4L 7.3L DIESEL V10 6.8L
Ford	F-350/350 SUPER DUTY	99-04	4 SP R/4WD	V8 5.4L 7.3L DIESEL V10 6.8L
Ford	F-450/550 SUPER DUTY	3/98-04	4 SP R/4WD	V8 7.3L DIESEL V10 6.8L
Lincoln	BLACKWOOD	2	4 SP RWD	V8 5.4L
Lincoln	NAVIGATOR	1/98-04	4 SP R/4WD	V8 5.4L

How to repair this transmission (Videos)

Teardown Inspection, No 2-3 UpShift

4R100 Teardown

4R100 rebuild

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme 4R100
web	Sonnax	6 Key Features to Understand in Ford E4OD, 4R100 & 5R110W

4L80E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission GM 4L80 was introduced 1990. It was used for trucks and SUVs with the engine capacity from 5 liters. This transmission is extremely reliable, powerful, and not complicated in terms of design. It has been installed on army armored vehicles Cobra and armored fighting cars Eagle for many years.The 4L80 is a famous predecessor the 3-speed 3L80. Many spare parts are interchangeable. In most cases, this transmission appears in repair services with Jaguars. It is also installed on powerful cars with engines from 5 liters including Hummer and Rolls-Royce.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/4WD	600	13,4	6,7	Dexron VI

Technical issues and repair guidelines

This transmission is a rare “guest” in repair services, thus it can be assumed that this unit is quite reliable. It went through many upgrades without serious changes (only rarely updating gaskets, seals, and filters). Clutch and brake packages are designed very reliably with such a huge reserve, that the type of friction elements hasn’t been changed since 1965.

The Direct clutch pack is the first to be worn-out and considered to be one of the weakest clutch packs. But it is quite normal and occurs after considerable mileages, extreme operating conditions and loads. If friction components of two abovementioned packs burn ATF for a long time and this ATF soaks in other friction linings, then the whole set of friction components should be replaced.

After 12-15 years of usage the wear-out of bushings becomes clear and vibrations exceed allowed limit, therefore repair specialists have to replace the whole set of bushings. Solenoids and the torque converter lock-up solenoid also reach the end of their service life by time. Almost all overhauls are performed when bushings, hollow discs, solenoids reach the end of their long service life. These transmissions easily operate for 200 thousand kilometers and even longer.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	C/K PICK-UP 1500-2500	95-00	4 SP R/4WD	V8 5.0L 5.3L 5.7L 6.0L 7.4L 6.5L DIESEL
Chevrolet/GM	VAN FULL SIZE 2500	96-09	4 SP R/4WD	V6 4.3L V8 4.8L 5.7L 6.0L 7.4L 8.1L 6.5L 6.6L DIESEL

How to repair this transmission (Videos)

Transmission repair

Teardown Inspection

Valvebody Repair and Vacuum Test

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme 4L80
pdf	Sonnax	Vacuum test 4L80-E, 4L85-E
web	Sonnax	Outsmarting 4L80-E Overdrive Roller Clutch Failure
web	Sonnax	Check Balls 4L80

4L30E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 4L30E is the successor of a reliable 3-speed transmission 3L30E, which has been used since 1969. These transmissions were made in the USA and in Europe (Strasbourg) under the name AR25 for RWD Opel Omega and AR35 for a 3-liter Katera.

The 4L30E has been installed since 1990 on RWD and AWD BMWs of all series with engine capacity of up to 3 liters, but it was more widely used on GM, Opel Omega, Isuzu and even on Honda Passport where it proved to be highly efficient.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/AWD	350	9,7	4,6	Dexron VI

Technical issues and repair guidelines

The torque converter, valve body and solenoids in the 4L30E transmission have a relatively limited resource. The operability of these components is gradually deteriorating because of the friction lock-up wear-out and accumulation of varnish in the narrowest places leading to the oil pressure drop and oil starvation, that results in a harmful impact on bushings, which have a proper resource.Operations with the worn-out pump liner and contaminated ATF lead to the oil pump damage. Plastic washer-bearings are also considered to be spare parts to be replaced.

The valve body after 200 thousand kilometers requires a statutory disassembly, repair and cleaning from varnish. The linear pressure solenoid was introduced in the valve body design for the brake band drive gear for regulation of the band pressure on the drum by means of PWM. Solenoids with exhausted resource are considered to be a typical problem in the electrical part of the transmission. The line pressure solenoid is also frequently replaced.

It is a reliable well-regulated transmission with a robust service resource for its components. After a simple overhaul this transmission can additionally operate for several years, if you properly monitor the ATF condition.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Acura	SLX	96-99	4 SP RWD	V6 3.2L 3.5L
BMW	3-SERIES	92-00	4 SP RWD	L4 1.8 1.9L L6 2.5L 2.8L
BMW	5-SERIES	90-99	4 SP RWD	L6 2.5L 2.8L
BMW	7-SERIES	00-01	4 SP RWD	L6 2.9L
Cadillac	CATERA	98-01	4 SP RWD	V6 3.0L
Honda	PASSPORT	94-02	4 SP RWD	L4 2.6L V6 3.2L
Isuzu	AMIGO	99-02	4 SP RWD	L4 2.2L V6 3.2L
Isuzu	AXIOM	02-04	4 SP RWD	V6 3.5L
Isuzu	RODEO	91-04	4 SP R/4WD	ALL
Isuzu	TROOPER	90-02	4 SP 4WD	V6 3.2L 3.5L
Isuzu	VEHICROSS	99-01	4 SP 4WD	V6 3.2L
Opel / Vauxhall	CATERA	00-01	4 SP RWD	V6 3.0L
Opel / Vauxhall	FRONTERA	00-04	4 SP RWD	L4 2.2L V6 3.2L
Opel / Vauxhall	OMEGA	00-03	4 SP RWD	L4 2.0L 2.2L 2.5L V6 2.5L 2.6L 3.0L 3.2L

How to repair this transmission (Videos)

4L30E Teardown

Band Adjustment

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual 4L30
pdf	www.at-manuals.com	Manual 4L30e

4HP20 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission ZF 4HP20 has been installed on a wide range of European FWD cars since 1995. This transmission is intended for the torque up to 330 Nm. ZF 4HP20 is used on Peugeot, Renault, Citroen with 2-3 liter engine. The 4HP20 unit has been installed on V-class Mercedes since 1998. This 4-speed transmission was used by PSA (Peugeot-Citroen) as the next modification of its AL-4 (DP0) for more powerful engines with the torque up to 330 Nm. This transmission lived up to all expectations by its dynamic characteristics and viability. It is a very reliable and low-maintenance transmission, which is mainly handed in for repair with the purpose of the filter change and replacement of gaskets and seals. The manufacturer assures that there is no need in fluid change during the first 10 years.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	330	8,3	3,5	LT 71141

Technical issues and repair guidelines

It is recommended to change fluid (Esso LT 71141) in this transmission after covering 60-80 thousand kilometers, depending on the driving style aggressiveness and transmission wear-out. The fluid level usually causes no problems, it is changed by means of partial change in several stages or complete change. The operation with insignificant fluid underfilling is also allowed, but the fluid overflow may be harmful for this transmission.

Typical problems with 4HP20:

The torque converter of the 4HP20 unit is the first component that cannot endure intensive exploitation. Initial vibrations caused by unevenly worn-out lock-up clutch lead to vibrations on the pump shaft and leakages through the seal. The next component to get out of order is the assembled oil pump. The bushing in the pump fails, forcing car owners to pay for replacement of the whole pump unit as neither bushings nor covers are supplied separately. The seal replacement without repair of the torque converter cannot solve the problem, but only buy some time.

Typical problems in electrical components of this transmission occur early and frequently. The valve body gets clogged with dirt, shavings and wear debris of friction components. In the course of the valve body repair it is quite common that some problems may occur with solenoids which exhausted their resource.

The next parts to be replaced in the 4HP20 unit are:

- Rubber-covered pistons in package F

- Piston of package D – wears out because of overheating

- Piston of package C – overheating

- Seals and piston cups of the pump and half-axle

The torque converter may have some problems when it stays neglected: wear-out of the lock-up mechanism, intended for blocking the clutch starting from the second gear. The torque converter quickly overheats and stops operating properly because of the worn-out lock-up clutch. The abovementioned factor leads to increase in fuel consumption, oil heating and pump operation, deterioration of acceleration characteristics, rapid wear-out of seals and bushings.The torque converter repair of the 4HP20 unit is more common in repair services than regularly repaired JF506, RE5R05, AXOD-E etc. But in general, this transmission is quite reliable, and when adhering to operational rules this transmission won't cause much trouble.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Alfa-Romeo	166	00-06	4 SP F/4WD	V6 3.0L
Citroen	C5	00-05	4 SP FWD	L4 2.0L 2.2L V6 2.9L
Citroen	JUMPER	00-06	4 SP FWD	L4 2.8L
Fiat	DUCATO	01-07	4 SP FWD	L4 2.8L
Fiat	ULYSSE	02-06	4 SP FWD	V6 2.9L
Ford	MONDEO	00-01	4 SP F/4WD	L4 2.0L
Hawtai	B11	11-15	4 SP FWD	L4 2.0L
Hawtai	BOLIGER	11-16	4 SP F/4WD	L4 1.8L 2.0L
Hawtai	E70	13-16	4 SP FWD	L3 1.5L L4 1.5L 2.0L
Hawtai	E90	15-16	4 SP FWD	L4 2.0L
Hawtai	NEW SANTA FE	15-16	4 SP FWD	L4 1.8L
Hawtai	SANTA FE C9	10-16	4 SP F/4WD	L4 1.8L 2.0L
Lancia	K	00-01	4 SP FWD	V6 3.0L
Lancia	PHEDRA	02-06	4 SP FWD	V6 2.9L
Mercedes-Benz	MB	02-04	4 SP FWD	L4 2.2L
Mercedes-Benz	V-CLASS	00-03	4 SP FWD	L4 2.2L 2.3L
Mercedes-Benz	VITO	00-03	4 SP FWD	L4 2.0L 2.2L
Peugeot	406/406 COUPE	00-04	4 SP FWD	V6 2.9L
Peugeot	407	03-10	4 SP FWD	L4 2.0L 2.2L
Peugeot	607	00-06	4 SP FWD	L4 2.2L V6 2.9L
Renault	SAFRANE	00-01	4 SP FWD	V6 2.9L
Zhonghua	COUPE	08-12	4 SP FWD	L4 1.8L
Zhonghua	ZUNCHI	12-16	4 SP FWD	L4 2.0L

How to repair this transmission (Videos)

Vito overhauling

4HP20 CONHECA

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual
pdf	drive.google.com	ZF 4HP20 Repair manual

4HP16 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission ZF4HP16 for was released in the early 2000-th, when its predecessor ZF 4HP20 was thoroughly tested under operational conditions. The 4HP16 unit is a reduction design copy of the4HP20 solution. ZF 4HP16 is intended for lower torque (up to 240 Nm) and mainly produced by Korean companies under the ZF licence for FWD cars such as Daewoo, Chevrolet (Lacetti), Grand Vitara etc with the engine from 1.6 up to 2 liters. This transmission is the competitor of the U240 unit.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	240	6,9	4	LT 71141

Technical issues and repair guidelines

The 4HP16 unit can be rarely found in repair shops. It it can be explained by the fact that this transmission, like all 4-speed ZF transmissions, is notable for its durablity and lack of major weaknesses. This transmission operates with different fluid types, but it is necessary to monitor the fluid level and its quality.

Repair and replacements

ATF change is accompanied by replacement of a one-time filter with a felt membrane. They are recommended for replacement after the second oil change, and for old cars – every time when changing the oil, that preserves solenoids and very expensive valve body.

Unilateral frictions usually get burnt in the clutch pack C. The responsive steel disc burns together with these friction elements. To solve this issue, ZF engineers changed the positioning of these three problematic friction discs in the following modifications. The piston is also frequently replaced during the transmission rebuilding. Spare parts in the 4HP16 unit are usually replaced in old torque converters. If this measure is neglected, then it may cause leaks in seals and the pump damage.

There are some minor problems with electrical components, which do not endure hot summer in the city and aggressive driving style with fluid overheating. Problems with contaminated solenoids lead to insufficient oil pressure resulting in problems with seals, bushings and pump with the torque converter. D and Е packages also get frequently damaged. Problems of old/worn-out transmissions (usually after 200 thousand kilometers) are similar to problems in the 4HP20 transmission.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	EXCELLE	03-09	4 SP FWD	L4 1.8L
Chevrolet/GM	EPICA	05-12	4 SP FWD	L4 2.0L
Chevrolet/GM	OPTRA	03-12	4 SP FWD	L4 1.8L
Chevrolet/GM	ORLANDO	10-11	4 SP FWD	L4 1.8L 2.0L DIESEL
Daewoo	LACETTI	02-11	4 SP FWD	L4 1.6L 1.8L 2.0L
Daewoo	LEGANZA	00-03	4 SP FWD	L4 1.8L 2.0L 2.2L
Daewoo	MAGNUS	00-03	4 SP FWD	L4 2.0L V6 2.5L
Daewoo	REZZO	00-08	4 SP FWD	L4 2.0L
Suzuki	FORENZA	04-08	4 SP FWD	L4 2.0L
Suzuki	RENO	04-08	4 SP FWD	L4 2.0L
Suzuki	VERONA	04-06	4 SP FWD	L6 2.5L

How to repair this transmission (Videos)

zf 4hp16 pictures

Zf4hp16 valve body

Zf4hp16 valve body2

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme

4F27E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic gearbox 4F27E was designed in 1998 for well-known FWD vehicles Ford Focus with the engine capacity from 1.3 up to 2 liters. According to Mazda classification, this models is also known as FN4A-EL. This gearbox is intended for lower torque. It is a remarkable solution which can be rebuilt without removing the whole mechanism. The cover is a common component for repair in this gearbox.

This easy-to-operate gearbox is still assembled on many plants of Ford-Mazda worldwide. The range of 4F27E /FNR5 is the most common Ford-Mazda gearboxes in repair services. Spare parts for repair of 4F27E (FN4A-EL) are almost the same as in the 5-speed FNR5.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	200	8	3,5	DexronVI / Mercon LV

Technical issues and repair guidelines

Clearance of the Reverse drum on the back cover stator.

Friction components of Overdrive and Reverse packages get burnt quite rapidly. Fast burning of these elements is related to design peculiarities of such type of gearboxes. Burning of these reliable friction elements occurs because the drum seating position on the rear cover support wears out and oil leaks out from teflon rings.

Back cover of the FN4A-EL

Specialists assume that the back cover issue is related to the stator’s material in the FN4A-EL. It is softer than in Ford (4F27E), therefore gearboxes for Ford have no problems with the rear cover.

Electrical elements in the 4F27E work properly for a long time.

The valve body is usually cleaned and rubber with gaskets get replaced with the help of the Overhaul Kit.

The differential is one more problematic component of “old” units. Ford updated the differential several times for different cars and now differentials of the 4F27E vary in quantity of “teeth”.
Rubber-covered pistons (Reverse, Forward, Low/Reverse) are the spare parts of second priority.

This gearbox is well-known among repair specialists, most parts for this gearbox are widely available. Proper exploitation and well-timed maintenance make this gearbox reliable and repairable.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	ECOSPORT	07-12	4 SP FWD	L4 2.0L
Ford	FESTIVA	0	4 SP FWD	L4 1.3L
Ford	FIESTA	08-13	4 SP FWD	L4 1.3L 1.4L 1.5L
Ford	FOCUS C-MAX	00-11	4 SP FWD	L4 1.6L 1.8L 2.0L 2.3L
Ford	I-MAX	07-10	4 SP F/4WD	L4 1.8L
Ford	IXION	04-05	4 SP F/4WD	L4 1.8L
Ford	LASER	00-05	4 SP FWD	L4 1.5L 1.8L
Ford	LYNX	00-05	4 SP FWD	L4 1.3L 1.6L
Ford	TELSTAR	0	4 SP FWD	L4 2.0L
Ford	TIERRA	00-07	4 SP FWD	L4 1.6L
Ford	TRANSIT CONNECT	09-13	4 SP FWD	L4 2.0L
Hongqi	MINGSHI	06-08	4 SP F/4WD	V6 2.0L

How to repair this transmission (Videos)

FN4AEL Teardown

Ford 4F27E Auto Tranmsission Rebuild

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Failures and Faithful Fixes for FN4A-EL and 4F27E
pdf	www.at-manuals.com	Scheme 4F27E
web	www.at-manuals.com	Stall test 4F27E
web	www.at-manuals.com	Solenoid application chart 4F27E

4L60E Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed family of GM transmissions named as TH700R4 (Turbo-Hydramatic) 4L60E/ 4L65E has been launched in production in 1982 and after some minor changes was renamed as 4L60. This 4-speed transmission for RWD cars was constructively based on the popular HydraMatic 700R4, but produced at the GM factory in Toledo (Ohio) and proved to be very efficient. This gearbox was used on RWD 4WD cargo vehicles and off-road vehicles with the engine from 3 up to 6 liters. It is the primary transmission for Hammers and also was used on Suzuki Vitara and SAAB. In 1996, engineers introduced a significant update and as a result the valve body control became electronic and it was named as the 4L60-E.

But the main innovation leading to high level of sales was the solenoid-regulator allowing soft shifting of gears and fast acceleration as well as control over the torque converter (TC) lock slippery. By 2001 the enhanced version of the 4L65E had been released. This modification was intended for the torque equal to 515 Nm. The next modifications of hydraulics and electronics and were introduced in 2001 -2003.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD/4WD	488	10,8	5	Dexron VI

Technical issues and repair guidelines

The TC lock-up clutch is the first element to wear out leading to oil contamination and clogging of solenoids with sensors. The TC unit in this transmission operates quite intensively, accelerating a powerful car with the help of the lock-up when the driver strongly pushes the throttle pedal to the floor.The clutch drum and the brake band frequently turn out to be a major issue for Hammers H2 and H3 with engines over 5 liters.

The first overhauls of the 4L60 consist in cleaning of the valve body (VB) and solenoids, repair of the TC unit with replacement of the lock-up unit and some spare parts. If the ATF and filter are replaced often and in due time, then the transmission operates properly for a long time. Solenoids are replaced as a full kit when their operating period comes to an end.

After covering 150-200 thousand kilometers the following units fail due to the transmission ageing (and first of all because of contaminated oil):

- Valve body separate plate

-Separator of the overrunning clutch, Forward (Input) Clutch and Low/Reverse.

Intensively operating rear planetary gear is usually replaced on old cars. The kit of valve body gaskets is one of the most frequently ordered spare parts. The kit of bearings is also ordered for the transmission reassembly. In general, these automatic transmissions are robust and consistent and after a standard overhaul they will serve for a long period of time.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	C/K PICK-UP 1500-2500-3500(95)	95-97	4 SP R/4WD	V6 4.3L V8 4.8L 5.0L 5.3L 5.7L 6.0L
Chevrolet/GM	VAN FULL SIZE 1500-2500	95-11	4 SP RWD	V6 4.3L V8 4.8L 5.0L 5.3L 5.7L 6.5L DIESEL
Chevrolet/GM	VAN FULL SIZE 3500	95-99	4 SP RWD	V6 4.3L

How to repair this transmission (Videos)

Gear Train Removal and Inspection

Valvebody and Pump Disassembly

Reverse Input Drum and Input Clutch Assemble

Reassembly of Pump and Gear Train

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Transmission scheme 4L60
web	www.at-manuals.com	Solenoids 4L60E
web	www.at-manuals.com	4L60/4L65E components
pdf	www.at-manuals.com	Scheme 4L60
pdf	www.at-manuals.com	Rebuild manual 4L60e
pdf	www.at-manuals.com	Repair manual 4L60e
pdf	www.at-manuals.com	Turning a 4L60E into a Manually Shifted Trans
pdf	Sonnax	Vacuum test 4L60-E, 4L65-E, 4L70-E
pdf	Sonnax	Recognize & Repair Solenoid Accumulators in Late-Model Valve Bodies
web	Sonnax	BUILD THE KILLER 4L60-E
web	Sonnax	4L60-E Valve Body Identification Guide
video	Sonnax	Guide to a Sonnax 4L60/E Level 3 Performance Build

4HP14 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission ZF 4HP14 found application on compact cars produced by Peugeot and Citroën, later it was installed on Daewoo models. This successful transmission also operated and on Volvo and Saab cars with engine capacity up to 2 liters. The main improvements in this transmission were implemented in 1986, and in 1989. Since then, the 4HP14 design hasn’t been seriously changed.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		5,4	2,5	Dexron III

Technical issues and repair guidelines

The main maintenance requirement for this transmission during many years of reliable service is timely ATF change (Dexron III or Dexron VI) and fiilter replacement every 100 thousand kilometers. The torque converter unit of this transmission easily operates for 200 thousand kilometers without any repair. There is no much information related to the repair of hard parts of the ZF 4HP14 unit to draw some patterns, because this transmission operates properly for a long time and the car gets too old before the first transmission overhaul.

The most popular parts ordered for the overhaul of this transmission are the following:

- filter

- Repair kit of gaskets and seals (Overhaul Kit),

- brake band

- pump bushing (or turbine shaft bushing) and friction clutches

In most cases, repair specialists have to repair frictions in the Forward pack and steel discs. The kit of steel discs is ordered not so often for repair, because friction components wear out rather than get burnt.Seal, pump, and turbine shaft bushing are the first to get burnt because of vibrations and overheating of the worn-out torque converter.

In all other respects, this transmission is quite simple and almost problem-free. After the valve body cleaning, the torque converter reassembly, and proper repair this gear shifting unit becomes extremely robust.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	AVEO	04-16	4 SP FWD	L4 1.6L
Chevrolet/GM	LANOS	05-09	4 SP FWD	L4 1.4L 1.5L 1.6L
Chevrolet/GM	VIVA	11	4 SP FWD	L4 1.6L
Daewoo	LANOS II	00-03	4 SP FWD	L4 1.4L 1.5L 1.6L
Fiat	PALIO	04-07	4 SP FWD	L4 1.5L
Fiat	SIENA	04-08	4 SP FWD	L4 1.5L

How to repair this transmission (Videos)

4 hp 14 volvo

BVA 4HP14 Citroën

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme

AX4N Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission AX4N was designed in 1994. It is the modification of its predecessor AX4S, which is in turn the modification of the AOD-E transmission.This transmission was not very popular and since 2004 it had been frequently replaced by German CVT CFT30 and the 6-speed transmission AF21 (TF-81SC) until 2007 when Mazda produced the 6- speed 6F50, and later (2009) - the enhanced 6F55.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	370	12,8	6,6	Mercon V

Technical issues and repair guidelines

The most popular spare parts rebuilding of this transmission are the following: repair kit of gaskets and seals (Overhaul kit). For all transmissions of this family installed on old cars, it is recommended to change ATF (Mercon V - Dexron-IV) with the filter each year after operation in hot summer time. It is required to check the ATF state for transparency. In many cases, problems of the AX4N are related to inconveniences in gears shifting caused by shortcomings of the valve body design, which gets clogged by friction dust.

Many specialists assume that the main reason of ATF contamination is the torque converter. The torque converter overheats ATF and facilitates to rapid oil contamination by friction wear debris, which quickly damage the valve body material. The manufacturer recommends installation of an additional transmission radiator.

Spare parts of the AX4N are sensitive to extreme operating conditions and as a result it leads to fast wear-out of all wearing elements, including brake bands Rear -Coast and O.D. - Overdrive, rubber-covered pistons. In the course of the transmission reassembly, it is recommended to check properly all rubber elements for elasticity of the rubber protection shield. The first compenents to get burnt are friction elments of the Direct package, and later Forward package. Other friction components wear out more rarely and often left untouched till the next overhaul.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	FREESTAR	04-07	4 SP FWD	V6 3.9L 4.2L
Ford	TAURUS	01-07	4 SP FWD	V6 3.0L
Ford	WINDSTAR	01-03	4 SP FWD	V6 3.8L
Lincoln	CONTINENTAL	95-02	4 SP FWD	V8 4.6L
Mercury	MONTEREY	03-06	4 SP FWD	V6 4.2L

How to repair this transmission (Videos)

AX4N Teardown Inspection, Part one

AX4N Teardown Inspection Part 2

AX4N Teardown Inspection Part 3

AX4N with code P0741

AX4N taking it apart

Instruction manuals and useful links

Link type	Source	Description
web	www.at-manuals.com	Scheme AX4N
0	Sonnax	Valve Body Layout AX4N, 4F50N

G4AEL Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The first Mazda's 4-speed automatic transmission G4A-EL was designed with partial electronic controlling mechanism (shift solenoids). This transmission was used on Mazda 626 since 1987. In 1989, after thorough testing and updating this great transmission found application in Ford Probe. According to Ford classification, named as 4EAT-G.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	230	6,8	3,5	Dexron III

Technical issues and repair guidelines

This transmission operates with different types of ATF manufactured by famous brands. It is recommended to change ATF only after estimation of its condition, and the older the car - the more frequently it is required to change ATF. In many cases, the torque converter lock-up wear-out clogs the valve body and damages solenoids. That leads to the torque converter repair and replacement of related spare parts.Complete reassembly of the transmission is performed with the help of Masterkit repair kit. This kit includes all gaskets and seals, all friction components and clutch discs. In terms of design, this transmission is similar to the F4A-EL (4EAT-F) and has the same common repair issues.

Every third repair of this transmission is minor and lies in replacement of the torque converter seals and gaskets (pan, pump and side valve cover) from oil leakage. At the same time specialists usually repair the torque converter with replacement of worn-out friction lining. The wear-out of the valve of linear pressure solenoids (EPC) and of the torque converter lock-up also causes many problems (jolts when shifting) in the GF4A-EL/ FU9A transmission.

Vibrations and rapid wear-out of bushings and seals start in case of a long oil starvation, which is usually related to the torque converter overheating, dirty valve body and solenoids. The brake band is one of typical spare parts, its successful design has not been changed since 1988. The drum Overdrive G4AEL 3-4 CL 42mm Overall Height (52,38mm OD Neck) 1986-2002 gets burnt together with clutches. Oil starvation leads to wear-out of friction surfaces. Repair specialists usually replace several essential gaskets and seals. The list of relevant spare parts also includes pan gaskets and the side cover gasket.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Ford	PROBE	90-93	4 SP FWD	L4 2.2L V6 3.0L

How to repair this transmission (Videos)

Transmission Failure Mazda

Ford F-4EAT

Replacement Auto Transmission

rebuild Fix Part 2 of 3

Failure Fix Part 3 of 3

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme G4AEL
web	www.at-manuals.com	Clutch application G4AEL
web	www.at-manuals.com	Valve body G4AEL

F4AEL Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission F4A-EL (KIA - 4EAT-F, F4E-AT) was designed by Mazda specialists together with Jatco in 1989 for FWD vehicles with the engine capacity of approx. 1.6 liters. This transmission had to replace the 3-speed F3A and was used for Mazda 323 and Ford Escort. In terms of design, this transmission is similar to the 4EAT-G.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	150	7,8	3,5	SP-III

Technical issues and repair guidelines

This reliable and simple automatic transmission in most cases comes in repair services with the torque converter issues and replacement of spare parts: repair kit of gaskets and seals. Friction elements of Forward, Overdrive 3-4 and Reverse packs are the first to get burnt because of wear-out of rings and bushings. Later, repair specialists packages Coast and L\R. With transmission aging it is required to replace the kit of bushings. Significant oil pressure losses and burning of friction elements in packages occur, when the wear-out of bushings exceeds 100 microns. The bushing of the torque converter hub is the first to wear out.

The clutch drum (Reverse & Forward Clutch Drum (only for Ford/Mazda)) gets replaced together with burnt friction elements, steel and bearing discs on old cars.Operation with contaminated ATF and vibrations related to wear-out of bushes has a bad impact on the oil pump. The rear cover is also replaced quite often (poor Y-alloy in Mazda). The valve body of this transmission has a specific distinction: for Kia- there is a valve 3-2, for Ford and Mazda- no valve. A new design of the valve body is very robust and has no problems of the first series. Timely detection of the burnt flavor and cleaning of the valve body with replacement of the EPC solenoid (or SHIFT - Ford/Mazda), 2-3 и 3-4.), which reaches the end of its service life, ensure reliability and a long-time service life of this transmission without any serious problems.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Mercury	TRACER	90-99	4 SP FWD	L4 1.8L 1.9L 2.0L

How to repair this transmission (Videos)

Kia Spectra Transmission

F4A-EL Case Lugs

1998 Escort Transmission

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Scheme F4AEL
web	www.at-manuals.com	TransTec Manual F4AEL
web	www.at-manuals.com	Stall test F4AEL

4EAT Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission Subaru 4EAT was manufactured in 1988 (EC8 = R4AX-EL). This transmission is related to the F-4EAT transmission model manufactured by Jatco. The modification released in 1999 was replaced the previous EC8 version on almost all popular Subaru models. This transmission was installed not only on low-powered Impreza and WRX, but also on middle class Forester and Outback with 2-2,5 liter engines, and even on powerful Legacy model with the engine capacity of 3 and 3.5 liters.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	300	9,5	6	Dexron III-VI / Mercon V

Technical issues and repair guidelines

Subaru vehicles with this transmission rarely come to transmission repair shops. In terms of maintenance services, this transmission is very similar to Jatco transmnissions. The 4EAT unit is a very reliable and simple system with special settings which do not allow drivers to overload prone-to-damage parts with a high degree of safety.

Overhauls usually consist of the reassembly procedure with replacement of the filter and repair kit of gaskets and seals. A kit of friction components is also commonly ordered by transmission specialists together with the abovementioned components. If the transmission operates for a long time with burnt fluid, then all steel discs get replaced with frictions. The external filter protects the valve body and solenoids from contaminated ATF, which appears because of the worn friction lining of the torque converter. Specialists recommend to replace it together with the engine oil filter on cars where the mileage parameter enxceeds 100 thousand kilometers, especially after a hot summer. The valve body unit of this transmission was updated in 1998 (type 2) and in 2001. These components are quite durable and require only timely cleaning.

If the transmission is overheated and has leakages through the pump seal of the torque converter and oil rapidly gets contaminated after the ATF, then the torque converter lock-up clutch is likely to wear out, and as a result damages the wheel hub. The torque converter is repaired and the valve body gets cleaned from the dirt, which appears from the damaged friction, and the overhaul kit is replaced. The first standard overhaul of the car with high mileage always includes replacement of pistons with frictions and a solenoid of linear pressure. The resource of this transmission is above the average and after a proper overhaul may be increased for several years.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Saab	9'2X	04-06	4 SP F/4WD	L4 2.0L 2.5L
Subaru	BAJA	03-06	4 SP 4WD	H4 2.5L H6 3.0L
Subaru	DEX	08-10	4 SP F/4WD	H4 1.3L
Subaru	FORESTER	98-12	4 SP 4WD	H4 2.0L 2.5L
Subaru	IMPREZA / WRX	93-11	4 SP 4WD	H4 1.5L 1.6L 1.8L 2.0L 2.2L 2.5L
Subaru	LEGACY	90-10	4 SP 4WD	H4 2.0L 2.2L 2.5L H6 3.0L 3.6L
Subaru	LOYALE	88-90	4 SP 4WD	H4 1.8L
Subaru	OUTBACK	00-10	4 SP 4WD	H4 2.5L H6 3.0L
Subaru	SVX	92-97	4 SP 4WD	H6 3.0 3.3L
Subaru	XT	87-91	4 SP RWD	H4 1.8L 2.7L

How to repair this transmission (Videos)

4EAT rebuilding

4eat transfer clutch

Servicing a Subaru Phase II 4EAT

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Manual
pdf	www.at-manuals.com	Repair manual
pdf	www.at-manuals.com	Scheme

A518 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The A518 was updated to 46RH (retainer hydraulic) and later to 46RE (retainer electronic). A618 was modified to 47RE and 48RE.

The family of 4-speed automatic transmissions "TorqueFlite" - A518/ A618 has been installed on rear-driven Dodge and Jeep with engines capacity about 6 liters (for A618 up to 8 liters) since 1990. This transmission is based on design of its predecessor А500.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD	610	13,4	4,8	Mopar ATF+4

Technical issues and repair guidelines

Filters for these automatic gearboxes are one-time-use with a felt membrane. With the mileage higher than 100 thousand kilometers, it is recommended to change filters with ATF. These transmissions are not very sensitive to oil type and its level, but with age oil cleanness has a greater significance for this transmission.In addition to the filter, specialists order the repair kit of gaskets and seals for the overhaul. In most cases, friction components are not ordered separately (if the oil has burning smell), but as a whole kit of frictions, which vary in years of manufacture. The kit of steel discs is ordered as well.The complete kit of spare parts Masterkit is ordered in roughly half the cases.

Popular parts to be repaired in A518/ A618:

Friction clutches and steel discs Direct and Forward operate more intensively than others and as a result get burnt. Frictions penetrated with burnt oil from the discs should be replaced.
The brake band (Reverse) is a spare part and should be replaced as often as the kit of friction componens. The list of spare parts also includes plastic discs-washers.

The electric part of the transmission exhausts its resource because of operation in overheated and contaminated ATF. Basically, controlling problems occur in the torque converter lock-up solenoid because of hot and contaminated ATF.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	DURANGO	98-03	4 SP R/4WD	V8 5.9L
Dodge	PICKUP/DAKOTA	98-00	4 SP R/4WD	V8 5.9L
Dodge	PICKUP/RAM 1500-3500	95-02	4 SP R/4WD	V8 5.2L 5.9L
Dodge	VAN/WAGON 1500-3500	95-03	4 SP RWD	V8 5.2L
JEEP	GRAND CHEROKEE	98	4 SP R/4WD	V8 5.9L

How to repair this transmission (Videos)

46RE Class introduction

46RE Class Part 1 Lesson 1

46RE Class Part 2 lesson 3

46RE Class Part 2 lesson 4

46RE Class Part 2 lesson 5

46RE Class Part 2 lesson6

46RE Class Part 2 lesson 7

48-RE Transmission - Valve Body Kit installation

46RE, 48RE transmissions

a518 transmission part 1

a518 transmission part 2

a518 transmission part 3

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout 46RH
pdf	Sonnax	Vacuum test 46RE, 46RH, 47RE, 47RH

45RFE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 45RFE was produced in 1999 for powerful 4.7 liter engines of Jeep and pickups Dodge Dakota. Subsequently, this transmission was adjusted for diesel engines (with the capacity equal to 2.8 liters). The 5-speed modification 5-45RFE has been manufactured since 2003.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		11	5	Mopar ATF+4

Technical issues and repair guidelines

These comparatively “invincible” transmissions in most cases come to repair shops for change of the oil and filters, which are replaced with dismounting of the pan. AWD modifications of this transmission have different oil filter and pan depth.

Scheduled overhaul includes the following spare parts in repair kits:

- Kit of gaskets and seals is replaced because of worn-out rings and valve body spare parts.

- Kit of friction components

- Kit of steel discs

These 3 kits compose the Master Kit. The kit of rubber-covered pistons is also ordered in case of the transmission overheating. Worn-out bushings also get replaced quite frequently.

Problems of these automatic transmissions occur when the valve body provides insufficient quantity of ATF. Solenoids also exhaust their limited service resource, the valve body gets clogged and wears out.The pump has 3 gears which are tested for wear and damages of operating surfaces. The pump bushing is also checked for wear. The pump has some issues with the wear-out of surfaces. The reason lies in a long-term operation with contaminated oil.The rubber-coated pump cover performs functions of the pump seal. This cover gets damaged by vibrations from the worn-out torque converter lock-up. There are several modifications of this cover.

Friction components with steel discs are the first to get burnt in Overdrive and Underdrive packages.This overheating of frictions in chain order leads to overheating of the valve body itself and electronics in the block of solenoids.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Dodge	DURANGO	00-02	4 SP R/4WD	V8 4.7L
Dodge	PICKUP/DAKOTA	00-02	4 SP R/4WD	V8 4.7L
Dodge	PICKUP/RAM 1500	02-05	4 SP R/4WD	V6 3.7L V8 4.7L
JEEP	GRAND CHEROKEE	99-00	4 SP R/4WD	V8 4.7L
JEEP	LIBERTY	2	4 SP R/4WD	V6 3.7L

How to repair this transmission (Videos)

45RFE Transmission Teardown Inspection

545RFE Teardown

45RFE Valvebody Overhaul

Instruction manuals and useful links

Link type	Source	Description
pdf	Valve Body Pro	45RFE Simplifying Sol's Codes
pdf	Sonnax	Valve Body Layout 45rfe
pdf	Sonnax	Vacuum test 45RFE, 545RFE, 65RFE, 66RFE, 68RFE

42RLE Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission 42RLE was designed jointly with 42LE (front-drive) and was produced since 2003, installed on the powerful RWD Chrysler of the 300-series, Liberty Jeeps, Cherokee (V6 and V8) and Dodge pickups with engines from 2.7 l up to 4 liters.

In terms of design, the 42RLE is a simplified rear-driven version of the FWD A606 (42LE), which doesn’t have the differential, chain and some other elements for the front drive.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		11	4	Mopar ATF+4

Technical issues and repair guidelines

The common repair kit for this transmission includes the following:

- repair kit of gaskets and seals.

- kit of friction components.

- kit of steel discs (less frequently)

This article covers the common issues with the Jeep Wrangler 42RLE Automatic Transmission, as well as some possible solutions. - Some of the more common problems include failed gear shifts, clutches and faulty torque converters, as well as sporadic torque converter clutch overdrive engagement problems. These issues can often indicate transmission problems which may require a rebuilt transmission. In some cases, a brand new transmission may be necessary. Older Jeep vehicles are especially prone to failure problems due to their age, and any indications of severe transmission problem should be addressed immediately. Symptoms such as loss of speed or torque converter speed can indicate a valve body issue which is a widespread issue in newer Jeep Wrangler vehicles.

This is when the transmission slips and may even cause your car to lose transmission fluid. This could be due to a faulty connection or the torque converter, which is what causes the transmission engine to slip. A slipping transmission can cause fault codes to appear on your vehicle's diagnostic scanner and indicate that you need repair. To fix this issue in a Jeep Wrangler, you will need to give your transmission a full flush and replace the valve body with a new one. This should stop your vehicle from slipping as it did before.

Causes of most transmission problems in a Jeep Wrangler can be traced to low fluid levels, leaks and lack of proper maintenance. Checking the fluid level in the transmission is one of the most common Jeep Wrangler problems. If the fluid level is too low, it can cause your car to slip or jerk as you shift gears. To avoid this problem, make sure to check your car's transmission fluid level regularly and top it off when needed. It is also important to get your car serviced regularly and use the right tools and experience to lessen transmission fluid loss due to leakages. Cars are unlike motors, so regular oil changes may not solve their problems; instead, you need to check their transmission fluids.

Automatic transmissions can be tricky and can cause a variety of problems. 42RLE Automatic Transmission Problems and Repair Solutions involve understanding the system, diagnosing the issue, and finding the right repair shop to fix it. Common problems include a transmission that tends to shift too hard or grinds when shifting. Many Dodge Ram owners experience problems in second gear where they enter a limp home mode and can only go up to 40 mph. To fix this, you may need to go to a repair shop and have your transmission flushed or replaced.

The 42Rle Automatic Transmission is found in some Chrysler vehicles and has been known to cause problems with shifting, dropping vehicle speed, and poor fuel economy. To operate the torque converter clutch, the transmission must first lock it in place. Once it is locked, the transmission will then disengage the clutch to help improve fuel economy when accelerating at certain speeds. If this does not work, you may need to unlock the torque converter clutch manually. The manual pdf that describes how to do this can be found online.

The torque converter lock-up wear-out usually results in vibrations and wear of the pump bushing (which is the same in A604-A606 and is included in the kit of bushings). The problem with the pump bushing manifests itself in leakages through the pump seal. If this problem stays neglected, then it may lead to the oil pump replacement.

The block of solenoids in the 42RLE is a common reason for many issues in this family of automatic transmissions. The resource of this block is not a large one, and the ТСМ unit loads solenoids quite intensively forcing the torque converter locking at the first opportunity to increase acceleration characteristics of the car.

The Clutch Hub (2-4 Clutch) is a typical vulnerability of these transmissions. In terms of design, this automatic gearbox has problems with the hub and a sun gear. The problem is also provoked by shortages of the oil pressure.Sensor Output Speed (VSS) and Input (TSS) cannot endure high temperatures and oil contamination by the metal dust. Pump bushings, gaskets, pistons, planetary gears get out-of-service because of insufficient oil pressure. These typical problems also occur in the family А604-А606.

This reliable transmission may serve for a long time. But it should be kept in mind that engineers of Chrysler wanted to win the competition with other fast automatic transmissions, therefore they adjusted TCM settings in such a way that the accelerator pedal easily forces the transmission work 101% of its capabilities without leaving any reserves.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chrysler	300 SERIES	04-10	4 SP RWD	V6 2.7L 3.5L
Dodge	CHALLENGER	08-11	4 SP RWD	V6 3.5L
Dodge	CHALLENGER	08-14	4 SP RWD	V6 3.5L
Dodge	CHARGER	05-10	4 SP RWD	V6 2.7L 3.5L
Dodge	DURANGO	04-08	4 SP R/4WD	V6 3.7L
Dodge	MAGNUM	04-08	4 SP RWD	V6 2.7L
Dodge	NITRO	07-11	4 SP R/4WD	V6 3.7L
Dodge	PICKUP/DAKOTA	03-11	4 SP R/4WD	V6 3.7L
Dodge	PICKUP/RAM 1500	06-16	4 SP RWD	V6 3.7L
JEEP	CHEROKEE	03-14	4 SP 4WD	V6 3.7L
JEEP	CHEROKEE	00-13	4 SP R/4WD	L4 2.4L 2.5L L6 3.6L 3.7L 4.0L
JEEP	LIBERTY	03-12	4 SP R/4WD	L4 2.4L V6 3.7L
JEEP	WRANGLER	06-16	4 SP R/4WD	V6 3.8L
JEEP	WRANGLER UNLIMITED	06-16	4 SP R/4WD	L4 2.8L V6 3.8L
Mitsubishi	ENDEAVOR	03-10	4 SP R/4WD	V6 3.8L
Mitsubishi	RAIDER	06-08	4 SP R/4WD	V6 3.7L

How to repair this transmission (Videos)

42RLE Teardown

42RLE/VLP Valvebody Overhaul & Install

Instruction manuals and useful links

Link type	Source	Description
pdf	ATRA	42RLE ATRA Technical Bulletin
web	wikipedia	Wikipedia article about 42RLE
web	Sonnax	42LE, 42RLE Variable Line Pressure

A500 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

Since 1988, the automatic transmission A500 had been installed on different models of Dodge pickups. After its modification in 1994 and renaming as 42RE (as electrically controlled transmission), it became used on famous Jeeps with the engine capacity equal to 4 liters and higher.

The 4-speed enhanced modification of 44RE named as A500 was developed for engines with a high torque (5-liter petrol-powered and 3-liter diesel engines). In terms design, this transmission is related to the TF6 (A904), and was installed on RWD vehicles and Mitsubishi pickups.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	RWD		11,6	4,5	Mopar ATF+4

Technical issues and repair guidelines

Repair kits of gaskets and seals and frictions are frequently ordered for repair of this transmission.The contamination of ATF and the valve body starts with wear-out of the torque converter lock-up. The torque converter rebuilding is recommended without waiting until the friction component damage to the glue layer.This family of RWD automatic transmissions allows drivers to use its capacity to the fullest and operates for a long time without the overhaul.

Because of transmission ageing, wear-out of the torque converter clutch (repair of the torque converter and friction replacement) and related to it overheating and oil starvation, specialists order the following parts:

- pump cover bushing

- pump seal

- Brake bands Kickdown and Reverse also considered to be "spare parts" and get replaced almost during each overhaul of an old vehicle.

The oil starvation often occurs because of problems with clogged valve body channels or as a result of improper operation of electric regulators and sensors. And it’s a consequence of a long-term exploitation with overheated and contaminated oil, caused by the worn-out torque converter lining. Torque converters on these transmissions should be repaired to prevent problems after covering 120-150 thousand kilometers.

Typical orders for the electirc part of the transmission:

- governor pressure sensor;

- ЕРС solenoid;

- block of solenoids;

- planetary gear (Front);

Specialists also frequently replace the Central support

- Gear selector is also ordered quite often for replacement.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Aston-Martin	VANTAGE	98-00	4 SP RWD	V8 5.3L
Dodge	DURANGO	98-02	4 SP R/4WD	V6 3.9L
Dodge	PICKUP/DAKOTA	95-03	4 SP R/4WD	V6 3.9L
Dodge	PICKUP/RAM 1500	95-02	4 SP R/4WD	V6 3.9L
Dodge	VAN/WAGON 1500-2500	95-96	4 SP RWD	V6 3.9L
JEEP	CHEROKEE	00-03	4 SP R/4WD	L6 4.0L
JEEP	GRAND CHEROKEE	94-04	4 SP R/4WD	L6 4.0L

How to repair this transmission (Videos)

A500 Rebuild Introduction

Part 1 - Tear Down

Part 2 - Valvebody Rebuild

Part 3 - Pump, Forward and Rear Clutch Rebuild

Part 4 - Bushing Replacement, Planetary Gear Train Rebuild

Part 5 - Overdrive Unit Rebuild

Part 6 - FINALE : Reassembly

Instruction manuals and useful links

Link type	Source	Description
pdf	Sonnax	Valve Body Layout 42RE

A606 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic transmission A606 is a modification of the A604 designed for FWD vehicles with a longitudinally positioned engine. It was designed in a couple of years after the release of its predecessor А604 (in 1993), and after two years of testing this model hit the market. In 1998, one more upgrade of this transmission was introduced with enhancement of the Reverse package and rings. According to athe new classification of Chrysler, the name of this automatic transmission (after 2003) was 42LE and this modification gained popularity.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		9,4	4,3	Mopar ATF+4

Technical issues and repair guidelines

This transmission is intended for engines with the capacity up to 3.5 liters. Many parts for this transmission are interchangeable with components from the А604. It was installed on Dodge, Chrysler, Mercury with 3 - 3.5 liter engines. A new differential and a chain were added.

Repair kits of gaskets and seals for A606 are not interchangeable with the one used for the A604. These kits are ordered almost for each repair and replacement of worn-out rings and overheated, hardened or cracked seals. Kits of friction components are universal and can be used for both transmissions. They are fully replaced, if burnt ATF reaches worn-out friction linings.The main problem of the electric part in both transmissions is the same – clogged valve body and block of solenoids. The block of solenoids for the A606 is reassembled with the use of repair kit (from the overhaul kit).

- RPM sensors are replaced

- Switch is replaced frequently (problem is caused by overheating.

Transmission components in “old” cars with the mileage higher than 200 thousand kilometers can not endure loads – in cars with powerful engines the following parts are replaced:

- Planetary gear

- Hub for frictions with a sun gear, (2-4 Hub w/Sun Gear).

- Hub for frictions (A604 Hub,Overdrive Clutch)

Steel discs burn together with friction clutches of the package Overdrive. Then burns their piston. The reason of this problem lies in the block of solenoids or worn-out bushings leading to the oil starvation in the package OD. Another typical problem of American automatic transmissions is the torque converter, which is very sensitive to even the slightest oil shortage. The planned rebuilding of the torque converter shouldn’t be postponed, if it is need.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chrysler	300M	99-04	4 SP FWD	V6 2.7L 3.5L
Chrysler	CONCORDE	95-04	4 SP FWD	V6 2.7L 3.2L 3.3L 3.5L
Chrysler	LHS	95-01	4 SP FWD	V6 3.5L
Chrysler	NEW YORKER	95-96	4 SP FWD	V6 3.5L
Chrysler	PROWLER	01-02	4 SP RWD	V6 3.5L
Dodge	INTREPID	95-04	4 SP FWD	V6 2.7L 3.2L 3.3L 3.5L
Eagle	VISION	95-97	4 SP FWD	V6 3.3L 3.5L
Plymouth	PROWLER	97-02	4 SP FWD	V6 3.5L

How to repair this transmission (Videos)

A606 Teardown Inspection

42RLE/VLP Valvebody Overhaul & Install

42RLE Teardown

42RLE New Tool for 4x4 Units

Chrysler 42LE Transaxle

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Manual A606
pdf	www.at-manuals.com	Repair manual A606
pdf	www.at-manuals.com	Scheme A606

A604 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 4-speed automatic gearbox A604 also named as "UltraDrive" (40TE/ 41TE) was designed in 1989 for front-wheel drive Chrysler vehicles and Dodge with engines ( 2-4 lit.). The structural design of the mechanical part of this transmission is based on well-known range of 3-speed gearboxes А404 - А413.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD		8,6	3,8	Mopar ATF+3

Technical issues and repair guidelines

The A604 transmission is one of the first gearboxes with added electronic computer responsible for all automatics of the hydraulics control, which adapts to the driving style and enhancing efficiency of operation of all transmission elements, including the torque converter (TC). Many spare parts can be replaced by parts for A606 (42LE) produced in 1993. In 2003, the A604 was updated one more time and renamed to 40ТЕ (for engines up to 2.4L), enhanced and well-known 41TE (up to 3.8 L).

For scheduled major repairs specialists usually include: filter, repair kits of gaskets and seals and frictions.

Typical problems are related to:

-Rear planetary gear

- Rear sun gear (wear-out of gears spline connections)

- Hub for friction clutches 2-4 with a sun gear.

- The set of hollow discs is replaced (reason: overheating, vibrations, ageing, contaminated oil with metal parts from shafts.

- The set of bearings is also replaced quite frequently.

The TC has a short operating resource. It should be handed in for repair with cutting and welding after 100-120 thousand kilometers (especially on powerful vehicles). The operation with the worn-out TC lock-up leads to beats and vibrations resulting in breakdown of the bushing and the pump seal.Typical repair of the “old” А604 consists of change of all bushings. This problem occurs when vibrations wear out bushings and oil dropping through bushings lead to the oil starvation.

Old automatic gearboxes have some issues with:

- Replacement of shaft rotation sensors

- Switch\ range sensor.

- different problems with differential bearings

- Rubber-covered piston

- Drum

This transmission reliably operates for a long period of time under the condition of yearly (or after 30 thousand kilometers) oil change and monitoring of its level and quality. If the oil is contaminated very rapidly, then it is advisable to check the TC operation and repair it on a timely basis.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Plymouth	GRAND VOYAGER	97-98	4 SP 4WD	V6 3.8L

How to repair this transmission (Videos)

41TE transmission with housing damage

604 Teardown Inspection

repair part 1

repair part 2

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Repair manual A604

3T40 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 3-speed automatic transmission GM 3T40 named as Turbo-Hydramatic 125C was installed on FWD cars with engine capacity from 2 up to 3.1 liters. The first modifications of this transmission did not have the torque converter, later versions (1995) had an electronic control and letter E was added to a new name GM 3T40E. The most significant modification was introduced in 1984. Since then sets of gaskets and seals have not been changed.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD	250	8,5	3,8	Dexron III

Technical issues and repair guidelines

The GM 3T40 is a reliable, simple transmission that operates over 300 thousand kilometers. It served as a prototype for the 4-speed family 4T40E -4T60E.This transmission rarely gets in repair services. The main spare parts ordered for repair of this transmission are the repair kit of gaskets and seals (Overhaul kit) or a complete Masterkit (with clutches and seals).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Buick	CENTURY/CENTURY WAGON	95-96	3 SP FWD	L4 2.2L
Buick	SKYLARK	95	3 SP FWD	L4 2.3L
Chevrolet/GM	BERETTA/CORSICA	95-96	3 SP FWD	L4 2.2L
Chevrolet/GM	CAVALIER	95-01	3 SP FWD	L4 2.2L
Chevrolet/GM	LUMINA	95	3 SP FWD	V6 3.1L
Oldsmobile	ACHIEVA	95	3 SP FWD	L4 2.3L
Oldsmobile	CUTLASS CIERA/CRUISER	95-96	3 SP FWD	L4 2.2L
Oldsmobile	SILHOUETTE	95	3 SP FWD	V6 3.1L
Pontiac	GRAND AM	95	3 SP FWD	L4 2.3L
Pontiac	SUNFIRE	95-02	3 SP FWD	L4 2.2L
Pontiac	TRANS SPORT	95	3 SP FWD	V6 3.1L

How to repair this transmission (Videos)

Valvebody Service and Seals

Disassembly and Inspection

Bushing Replacement and Painting

Instruction manuals and useful links

Link type	Source	Description
pdf	shop.ukrtrans.biz	Manual ATSG 3T40, 125C
pdf	shinseiauto.com	Transmission breakdown illustration 125C
pdf	at-manuals.com	Diagnosis and general service 125C
web	Sonnax	GM 125C Checkball Locations

3L80 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

3-speed automatic gearbox THM (Turbo Hydromatic) 400, also named as 3L80). Turbo-Hydramatic is a patented name for the family of automatic gearboxes designed and produced by GM.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	RWD	340	12	5	Dexron III

Technical issues and repair guidelines

This gearbox 3L80 has a simple and reliable design. All parts are made of solid materials. Shifting of gears is implemented very smoothly and almost unnoticeable. The main disadvantages of this automatic transmission are significant dimensions and weight of the transmission. This transmission is considered to be the most reliable in the history of GM (the most enduring).

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chevrolet/GM	H1 HUMMER	92	3 SP 4WD	V8 6.2L DIESEL

How to repair this transmission (Videos)

3L80 aka Turbo Hydramatic 400 tear down

Transmission Rebuild

Instruction manuals and useful links

Link type	Source	Description
web	Wikipedia	Super Turbine 400 / THM400 / THM375 / 3L80 / 3L80HD
pdf	Makcotransmissionparts	Transmission breakdown illustration
web	Sonnax	Setting Total Endplay to Prevent TH400 Gear Train Failure

A413 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

This popular family of 3-speed automatic transmissions A404 / A413 / A470 / A670 had been successfully installed since 1981 on FWD vehicles Chrysler, Dodge and Plymouth of a middle class for nearly 20 years.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
3	AT	FWD		8,4	3,8	Mopar ATF+3

Technical issues and repair guidelines

The overhaul kit of gaskets and seals is frequently ordered by transmission specialists for repair of automatic gearboxes of this family. Specialists also order a complete kit of frictions. Friction components are replaced if the ATF has burning smell and its hard to set clearances in packages. A typical repair procedure of this transmission family includes the replacement of all spare parts (including the kit of friction components, steel discs and brake bands.Ageing process and overheating lead to the wear-out of plastic discs (washers) which are replaced during the overhaul. Specialists also frequently replace a complete kit of bushings. Worn-out bushings lead to the oil starvation of frictions.

The list of spare parts for this transmission also includes:

- The kit of the overrunning clutch separator (springs and rollers)

- The pressure centrifugal regulator (Governor) is usually rebuilt.

- Solenoid of the torque converter lock-up for А670 introduced in the hydraulic 3-speed for switch-on of an early lock-up.

A404 /470 /670, 30TH/31TH is a family of unique transmissions produced by Chrysler having a solid reserve of transmission components.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Chrysler	PT CRUISER	0	3 SP FWD	L4 2.4L
Chrysler	VOYAGER	1	3 SP FWD	L4 2.4L V6 3.0L
Dodge	CARAVAN/GRAND CARAVAN	95-00	3 SP FWD	L4 2.4L
Dodge	NEON	95-01	3 SP FWD	L4 2.0L
Dodge	SPIRIT	95	3 SP FWD	L4 2.5L V6 3.0L
Plymouth	ACCLAIM	95	3 SP FWD	L4 2.5L V6 3.0L
Plymouth	NEON	95-01	3 SP FWD	L4 2.0L
Plymouth	VOYAGER/GRAND VOYAGER	95-00	3 SP FWD	L4 2.4L

How to repair this transmission (Videos)

Teardown Inspection

Instruction manuals and useful links

Link type	Source	Description
0	www.at-manuals.com	Technical training A413
pdf	www.at-manuals.com	Scheme A413
web	www.at-manuals.com	Solenoid application chart A413

6HP19 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 6-speed automatic gearbox ZF 6HP19 /A (09 ) has been installed on RWD and AWD BMW models, as well as on FWD and AWD Audi models (as 6HP19A). This transmission can be paired with engines with capacity up to 3.5 liters. ZF 6HP19 was constructed jointly with ZF6HP26 as a “light” modification. Aisin’s TR-60S and VW's DSG-6 are considered the main competitors of this ZF unit. VAG is the main user of ZF transmission solutions. In 2006, ZF released 6HP21 and 6HP28 modifications. These two units have the same new Mechatronic unit of the 2nd generation with improved gear shifting mechanism. ZF engineers also improved the valve body, replaced solenoids, replaced some friction elements and almost all steel plates

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/RWD/AWD	420	9	4	Shell M-1375.4

Technical issues and repair guidelines

ZF recommends changing ATF in this transmission no later than after covering 100 thousand kilometers or after 8 years of running under the condition of "careful" driving style. The amount of required ATF for a full change is 9.5 L. This gear shifting unit operates with any good quality fluid such as Dexron VI. It is advisable to make two partial fluid changes in case of contaminated fluid and at the same time to change the filter.

Transmission specialists usually replace solenoids when the car with this transmission reaches high mileages and problems with gear shifting. The torque converter is also rebuilt in the process solenoid replacement.The complete reassembly includes removal of the transmission unit, and order of the repair kit of gaskets and seals. In the process of reassembly, the whole set of friction components is replaced, especially when ATF gets burned. The full kit of bushings is replaced as well.

Typical problems of ZF 6HP19-21

The most common problem for powerful cars equipped with this transmission is the torque converter. Its locking mechanism became regulated and forced from the first gear.The main problem of 6HP19\21 – is the Mechatronic unit. Electronic components are sensitive to temperature drops and falls– too high and too low oil temperatures as well as the presence of metal chips are undesirable factors for this transmission.The main spare part of 6HP valve body became the separator plate of the valve body.

Structural peculiarities of this gear shifting unit (vibrations of torque converter and pump stator, operating with oil shortage...) lead to fast wearing of bushings.The wear of bushings results in pressure losses in corresponding packages and the control unit opens electromagnetic valves of solenoids more and more in order to compensate oil shortages. Common replacement part – the pump seal, and less frequently - output shaft seal. Transmission specialists frequently replace worn pump bearings.

The main problem for the 6HP19 unit in winter time is replacement of the adapter to the block of solenoids (also called as “Sleeve”). It is recommended to replace the “Sleeve" within the framework of the sheduled repair without waiting for its damage. The common spare part in summer time is the adapter to mechatronics. This adapte, included in some repair kits, has a short service life and recommended for change each 2-4 years. With this repair part, it is also advisable to replace sealing tubes of the valve body.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	S4/RS4	04-09	6 SP 4WD	V8 4.2L

How to repair this transmission (Videos)

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Spare parts catog 6HP19
web	www.at-manuals.com	Solenoids manual 6HP19 (09L)
pdf	Sonnax	Valve Body Layout ZF6HP19/26/32 (Gen. 1) With 053 Separator Plate
pdf	Sonnax	Valve Body Layout ZF6HP19, ZF6HP26, ZF6HP32 (Generation 1)
pdf	Sonnax	ZF6HP21/28/34 (Generation 2) Valve Body Layout
pdf	Sonnax	Vacuum test ZF6HP19/26/32 (Gen. 1) with 053 Separator Plate
pdf	Sonnax	Vacuum test ZF6HP19/26/32 (Gen. 1)
pdf	Sonnax	ZF6HP21/28/34 (Generation 2)

6HP26 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

This 6-speed automatic transmission was designed by ZF jointly with BMW. Since 2001 this transmission has been used for all high priced vehicles with rear-wheel drive and engines with the capacity of up to 6 litres. The list of brands using this transmission includes Bentley, Aston Martin and Maserati. Since 2006 this transmission has been used in Ford, Hyundai, Jaguar, Land Rover.The 6HP26A modification found application on FWD Audi and VW models. It has the torque capacity of up to 600Nm.This 1-st 6-speed automatic transmission from ZF triggered the start of production for next generations of this family - 6HP19 -21 intended for engines with lower torque (up to 420 Nm) and 6HP32 – for max torque (up to 750 Nm).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	FWD/RWD/AWD	420	12	6	Shell M-1375.4

6HP26 Specs

The gearbox is controlled by a revolutionary for that time TCM (transmission control module) named the ZF 6HP Mechatronic / Mechatronik. The 6HP26 torque converter boasted an innovative lockup system with a peculiar mechanism, which facilitated lockup in all 6 gears. Multiple gear ratios in the ZF 6HP26 transmission were housed inside a small area, using a conventional planetary gearset and a gear assembly designed by P.Ravigneaux. Power transfer actions are covered by 5 clutch packs. At that, compared to its predecessor, the ZF 5HP, this 6-speed transmission used fewer parts and was lighter

6HP26 Typical problems, technical issues and repair guidelines

Typical problems for this transmission family includes: vibrations which lead to wear of bushings and drum Е resulting in problems with 4-5-6 gears shifting; issues with other speeds caused by wear of solenoids and torque converter lock-up result in problems with the pump and seal leakage, slippage of frictions (slow acceleration) which leads to overheating, burnt oil and necessity for automatic transmission reassembly with the use of repair kits.

6HP26 Mechatronic problems

The mechatronics unit is similar to the one used in 6HP19 and they have the same problems. There are two generations of valve bodies.VFS (Variable Force) solenoids frequently become the source of numerous issues. Intensive operation on cross-section in the environment of contaminated fluid and high temperature leads to premature wear and abnormal operation. Mechatronics in these ZF automatic transmissions are sensitive to static electricity, even when touching contacts with your hands.

6HP26 Mechatronic Seal Issues

Issue: a range of common 6HP26 transmission are frequently due to loss of pressure from the required level caused by the wear or failure of the small seal between the 6HP26 transmission mechatronic controller and the transmission case. If it fails, the following 6HP26 transmission problems will manifest themselves:

Unexpected 6HP26 clutches failure,
Transmission pump malfunction,
Failure of the torque converter clutch.

Solution: replacement and reinstallation of the 6HP26 Mechatronic adapter seal.

6HP26 Pump problems

Worn pump bearing and pump stator are frequently replaced during maintenance services. Problems of both abovementioned parts are related to worn components of torque converters and related vibrations. Typical replacement operation of the first priority is related to the overheating and aging of the rubber: - Separator plate of the valve body, 6HP26/ 6HP19.Overdrive Е package with frictions, steel and thrust discs gets burned first from clutch packs. The same problem is typical for structurally similar 6HP19.The problem in winter time – replacement of the adapter to the solenoid assembly.

6HP26 Torque converter problems

The torque converter is a common problem for powerful vehicles equipped with this transmission. If repair specialists order bushings, then it means the torque converter repair as well.After the overhaul it is required to reset computer settings. This family of ZF6HP transmissions is in great demand in the repair business and at the same time is considered to be as repairable as its predecessor - 5HP19. The service life of this transmission can reach 1 “million” kilometers under the condition of timely and accurate overhaul of the transmission (as well as maintenance).

Excessive wear of the TC clutch in the 6HP26 torque converter due to active lockup triggered even at as low as 1st gear. Subsequently, drivers can experience the following problems:

Delays in engaging the right gear,
Slipping gears,
Unpredictable up/down shifting,
Excessive heating of the transmission,
Unusual noises from the transmission.

Solution: key to remedying the ZF 6HP26 torque converter problems is installation of a new / replacement torque converter unit. Torque converter repair specialist might effectively use certain special tools helpful in the remanufacturing procedure. It is also important to remember to address replacement of the excessively worn transmission fluid and issues with cooling.

6HP26 Solenoid Issues

Issue: different gear ratios are controlled by 7 solenoids and if one of these 6HP26 solenoids becomes damaged or worn out, following problems arise:

Delays in shifts,
Sticking gears,
Refusal to turn a gear,
Slipping gears.

Solution: a serious number of common problems with 6HP26 transmission is due to valve body solenoids failures. The right approach to remedy this is replacement of the faulty 6HP26 solenoid. Solenoid testing equipment is recommended to identify the damaged one.

6HP26 E Clutch failure

Issue: wear out of the 6HP26 clutches, which are key in power transfer from one gear to the next. Friction material used in the clutches is important for grabbing. Improper maintenance or reckless driving will wear them out prematurely. The common 6HP26 clutch failure symptoms are as follows:

Clutch slipping,
Delays in shifts,
Harsh shifts,
Failure of gear engagement,
Excessive heating.

Solution: rebuilding or replacement of the transmission unit corrects this common 6HP26 transmission issue.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A4/A4 CABRIOLET	02-13	6 SP F/4WD	L4 2.0L V6 3.0L V8 4.2L
Audi	A6	04-11	6 SP F/4WD	V6 3.0L V8 4.2L V10 5.0L 5.2L

How to repair this transmission (Videos)

Teardown

Bushing Kit Installation

Bushing Kit Installation Part 2

Valvebody Overhaul

E-Shift Valvebody

ZF 6HP Rebuild

Remove Mechatronic Case Connector

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Transmission breakdown illustration 6HP26
pdf	www.at-manuals.com	Spare parts catalog 6HP26
web	www.at-manuals.com	Pockets 6HP26
pdf	www.at-manuals.com	Scheme 6HP26
web	www.at-manuals.com	Application chart 6HP26
pdf	Sonnax	ZF6HP19, ZF6HP26, ZF6HP32 (Generation 1) Valve Body Layout
pdf	Sonnax	ZF6HP19/26/32 (Gen. 1) With 053 Separator Plate Valve Body Layout
pdf	Sonnax	ZF6HP21/28/34 (Generation 2) Valve Body Layout
pdf	Sonnax	Vacuum test ZF6HP19/26/32 (Gen. 1) with 053 Separator Plate
pdf	Sonnax	Vacuum test ZF6HP19/26/32 (Gen. 1), FORD 6R60/6R75/6R80
pdf	Sonnax	Vacuum test ZF6HP21/28/34 (Generation 2)
web	Sonnax	Solving the 6R80 Transmission Leak Mystery

09D Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The TR60-SN (09D according to VAG) is an innovative 6-speed automatic transmission designed by Aisin and released in 2003 for RWD Porsche Cayenne equipped with a 4-liter engine.

This transmission was designed simultaneously with the first 6-speed automatic transmission for FWD cars - TF60-SN and was tested since 2001 on a 2-liter Altezza

This transmission was supposed to be a leader in the world of luxury brands such as Porsche, Audi, Lexus and become a competitor to the new 6-speed ZF6HP transmission. Audi use 09D for Q7 SUVs with diesel engines from 3 to 4.2 liters.

EAW TR-60SN has been successfully used since 2007 in powerful (over 4.6l) RWD and AWD Lexus and Land Cruiser SUVs. There are several sub-modifications of this transmission for its torque class, differing in planetary gears, quantity of clutches and steel discs, the size of some of the units and parts. It was replaced by the 8-speed transmission TR80-SD.

This transmission was designed by the Aisin to become "invincible", like all of its RWD automatic transmission. But each automaker customized its TCM (transmission computer) in "democratic" fashion, enabling drivers to use its capacities to the fullest extent.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
6	AT	RWD/AWD		12	8	Toyota WS

Technical issues and repair guidelines

The repair kit of gaskets and seals is always ordered with filters for reassembly procedure. It is usually ordered for changing teflon rings which must be changed to save friction components and the pump with solenoids. If the car is used with worn out teflon rings, then the friction elements get burnt and the rubber seals get harder because of the temperature.The overhaul is always accompanied by the replacement of burnt frictions and steel disks for K1, K2, B1 clutches. The reason is usually related to clogged valve body, solenoids, and seals. It is expressed in slippage of clutches under load or delays with shifting of gears.

The most problematic components of 09D:

The main problem of 09D installed in Volkswagen is related to clogging and breakdown of the hydraulic clutch plate with solenoids caused by ATF overheating and burning of the hydraulic clutch friction lining.
The torque converter is usually handed in for repair in order to replace worn-out clutch lock-up.
The wiring of solenoids often causes some malfunction. Older transmissions are provided with external fine filter.
Valve bodies for Tuareg are often handed in for repair.

For these transmissions it is recommended to take measures on improving the transmission cooling system, for example, by installing an additional radiator. It is also advised to check the ATF condition and change it as soon as it gets darker and loses transparency.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	Q7	05-13	6 SP R/4WD	V6 3.0L V8 4.2L
Volkswagen	TOUAREG	02-10	6 SP 4WD	V6 2.7L 3.0L 3.2L 3.6L L5 2.5L V8 4.2L V10 4.9L W12 6.0L

How to repair this transmission (Videos)

Pressure-Test front pump seal

09D SHIFT KIT

AW 6 Speed Solenoid Repair

Instruction manuals and useful links

Link type	Source	Description
pdf	volkspage.net	Self-Study Programme TR60SN 09D
web	sonnax.com	TR-60SN Valve Body Layout
pdf	ukrtrans.biz	TR60SN Technical Service Information
web	www.at-manuals.com	Component application chart TR60SN 09D
web	www.at-manuals.com	Solenoid/clutch application chart TR60SN 09D
web	www.at-manuals.com	Valve Body with solenoids TR60SN 09D
pdf	Sonnax	Valve Body Layout TR-60SN

5HP19 Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 5-speed automatic transmission ZF5HP19 (with ./FL ../FLA modifications) - is considered to be one of the most popular automatic transmissions in the repair industry. Although this transmission was replaced by no less popular ZF6HP26 - 6HP19, this 5-speed unit is still widely used and repaired.

It should be noted that the popularity of this transmission among repair specialists has nothing to do with its quality, on the contrary, this efficient transmission was installed on extremely durable cars. It is the case when good cars get a good transmission. First 5HP19 units were introduced in 1995 on front-wheel and all-wheel drive Audi. These gear shifting solutions were designed on the basis of 4-speed 4HP18 and 5-speed 5HP18 (thus, most of components in these transmissions are identical). The main peculiarity of 5HP19 is higher torque in comparison with 5HP18 and that it can be paired with engines up to 4 litres. The FL version of this transmission was designed for the line-up of FWD models from Audi-Volkswagen. The 5HP19FLА transmission is designed for 4WD cars with V6 engines. The 5HP19 unit found application in rear-driven BMW cars. According to VAG classification, ZF 5HP19 transmission is also known as 01L or 01V (for some vehicles).

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
5	AT	RWD/AWD/FWD	325	9,7	4-5,5	LT -71141

Technical issues and repair guidelines

The repair kit of gaskets and seals for BMW is the most popular kit ordered for this transmission. The kit of frictions is also included in a standard order for this transmission.

The operational resource of this transmission before the first overhaul is significantly higher than standard 120,000 miles, but this parameter heavily depends on operating conditions. This reliable transmission can endure operation under severe conditions and heavy loads, but oil starvation will have a negative impact on its operability.

The torque converter of this transmission is one of the most frequently repaired units. This torque converter is one of the first converters with early introduced ( 3-rd speed) forced lock-up mechanism, which damages the friction lining. The pump cover bushing is one of the most frequently replaced elements.

As for friction discs in the 5HP19 transmission, in most cases repair specialists have to replace discs of the first "С" package near the pump. The replacement of friction components is always accompanied by replacement of sealing rings as the wear-out of these rings leads to burning of friction packages.

The pressure solenoid (EDS-1 EPC) is loaded more in comparison with solenoids, therefore it works out its resource earlier.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	S4	00-02	5 SP 4WD	V6 2.7L

How to repair this transmission (Videos)

ZF 5HP19 transmission assembly

Rebuild Part 1 BMW

Rebuild Part 2 BMW

ZF5HP19 Teardown

Gear Monitoring Codes

Valvebody

valve body additional information

Torque converter

Instruction manuals and useful links

Link type	Source	Description
pdf	www.at-manuals.com	Spare parts catalog 5HP19
pdf	www.at-manuals.com	Repair manual 5HP19
web	Sonnax	ZF5HP19 Solenoid Identification

01N Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

In 1991, the 4-speed automatic transmission (A/T) 01N (097) successfully replaced another popular transmission solution named as 090. It was designed for FWD Audi cars (A4, A6, etc.) equipped with engines from 1.6l to 2.6l. It was also installed on some VW Passats with different longitudinally positioned engines with the capacity up to 1.9 liters.The transmission, manufactured from 1991 to 2004, has three modifications corresponding to their production years: 1991-95; 1996-1998; 1999-04. Thus, these versions have some differences in the design of transmission components.VW have similar modifications of this family: 098/01P – the engine is located transversely in minibuses and MPVs. VW Sharan, VW T2/T4, VW Eurovan, Ford Galaxy; 095/096/01M – the engine is located transversally for VW and SСODA cars.These automatic transmissions differ in housings and differentials.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	280	6	3,8	LT 71141

Technical issues and repair guidelines

The 01N (together with 098/01P and 095/096/01M) - the leader among Audi-VW transmissions in repair frequency. The 01N steadily holds the third place in demand, behind only a younger family U140-240 and the unconditional leader 5HP19(FL).This transmission is very reliable, maintainable, simple, and some problems usually occur only after large mileages.

Often transmission specialists change only the burned-out 3-4 (K3) packs and Forward-Rev together with bearing discs, separate plastic bearings, gaskets, pump and seals. Electric components and the valve body units usually have tha same issues as in the 01M transmission. The torque converter is the main source of faulty operation of the valve body. The sooner the torque converter lock-up lining is replaced, the less is the wear-out of solenoids and the valve body.

The standard order for reassembly of the old 01N transmission includes filter and complete kits: Overhaul kit, Frictions, Pistons.

Ordered Kits:

-Kit of gaskets and seals;

-Kit of friction components, usually ordered with the kit of steel discs;

-Kit of pistons is the same for 01M-N-P, and it is ordered for most major repairs.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A4/A4 CABRIOLET	00-01	4 SP F/4WD	L4 1.8L V6 2.6L 2.8L

Instruction manuals and useful links

Link type	Source	Description
pdf	www.parker.com	TRANSMISSION KIT & COMPONENTS CATALOG

01M Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The legendary 4-speed automatic transmission 01M of Audi-Volswagen own manufacture (preceded by 095 / 096 models) has been produced for 20+ years, from 1995, for all popular FWD VW, Seat and Skoda (as well as Audi А3) vehicles with engines from 1.6l to 2.0l positioned transversally.

The most popular transmission in rebuilding is the 096 transmision. It had been assembled at some Volkswagen factories until 2009, while the 01M has been installed on the Passat series (China) up to the date. The German factories used the the 01N unit on the Passat series with various engines (A4, A6, Cabrio).

The less popular modification 01P (its predecessor is 098) capable of transferring a higher torque was used with up to 2.8l engines in VW Sharan, VW T2/T4, VW Eurovan, Ford Galaxy (micro buses and minivans). In terms of design, this transmission is similar to the 01M and these models have many compatible spare parts.The 097 transmission had been used in Audi 80 and 100 models unil 1995, when it was replaced by not less reliable 01N.

This family of automatic transmissions was the last masterpiece of VW-Audi Group, which tried to stay competitive on the automatic transmission market. The 5-speed ZF 5HP19 released in 1995 smoked the competition, and VAG soon decided to close the production of its automatic transmissions and started using products of Aisin Warner and ZF.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
4	AT	FWD	200	6,5	3,8	LT 71141, 75W90 GL4

Technical issues and repair guidelines

One of the peculiarities of the 01M transmission lies in the transversal positioning of the unit. Therefore, VAG engineers also had to add a differential with a separate lubrication system (i.e. oil for it is tested and replaced separately).Gasket and seal repair kit (Overhaul kit) for the 01M is frequently ordered for the transmission repair. Rebuilding procedures, especially when there is burnt oil, require a full set of the friction components.

The list of 01M vulnerabilities includes the following:

The rubber hardens and poorly endures pressure, especially in winter. Older vehicles and overheated automatic gearboxes have the full set of rubber-coated pistons replaced in them.
The drum 3-4 may become worn out due to breaking of the basket along the axle of the shaft.
The green front drum washer - plastic sliding bearing - melts or becomes brittle due to the temperature and lateral pressure effect.
It is believed that 8-10 years is the average normal lifespan for all 01M-01N electrical components, including sensors. After this term, the resistance of its wiring starts to increase, the channel gets worn out, the characteristics of the valve closure change, and the computer "rejects" them.
The Valve Body requires regular cleaning. For vehicles that covered over 150-200 thousand km this procedure is a “must”. (As well as Torque Converter rebuilding)
ATF contamination comes from the Torque Converter and is a result of the dust flow from friction linings and worn out bearing washer. Contaminated ATF blocks channels and corrodes metal of these channels at some most loaded valves of the Hydraulic unit.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A3	00-06	4 SP F/4WD	L4 1.6L 1.8L 1.9L
Seat	TOLEDO	96-01	4 SP FWD	L4 1.6L 1.8L 2.0L
Volkswagen	CABRIO	95-01	4 SP FWD	L4 2.0L
Volkswagen	GOLF/GTI	95-06	4 SP FWD	L4 1.8L 2.0L 1.9L DIESEL
Volkswagen	JETTA	02-05	4 SP FWD	L4 2.0L 1.9L DIESEL
Volkswagen	PASSAT	95-11	4 SP FWD	L4 1.9L 2.0L V6 2.8L

How to repair this transmission (Videos)

Automatic Transmission Service Group

VW 01M Transmission

Instruction manuals and useful links

Link type	Source	Description
web	Wikipedia	Volkswagen 01M transmission
web	kansascitytdi.com	01M Transmission Removal and Reinstallation
web	kansascitytdi.com	01M Valve Body Removal and Reinstalation
web	kansascitytdi.com	01M or 01P Valve Body Repair
pdf	just-t4s.co.uk	01M, 01N, 01P UNCONTROLLABLE HARSH 1-2 UPSHIFT
web	kansascitytdi.com	01M Filter change
pdf	europeantransmissions.com	01M/01N/01P 1996-2000 OBD-II CODE DEFINITIONS

01J Transmission parts, repair guidelines, problems, manuals

Mon, 15 Dec 2025 00:00:00 -0700

Transmission general data

The 01J CVT transmission ( 0AN Multitronic or VL-300) was produced by Audi collaboratively with the company LuK GmbH & Co in 2002 for popular AWD models А4, А6, А8 with engines from 1.8 up to 3 liters. It transmits up to 310 Nm of torque.

Audi came up with a lot of names for different sub-modifications of this transmission, but all these CVTs versions have basically the same design and internal components and can be repaired with the help of the same repair kits.

Number of gears	Transmission Type	Drive	Torque (Nm)	ATF (full capacity) L	ATF (change) L	ATF type
∞	CVT	FWD	310	7,5	4,5	G 052 180 A2

Technical issues and repair guidelines

The main reason for visiting a repair shop with this durable CVT during the first years of exploitation is the necessity to replace the filter and ATF (G 052 180 A2). About 4.5 liters are required for partial ATF change. Complete ATF change via double partial change - requires 7.5 liters. This CVT is sensitive to the CVT quiality (level and cleanness). It is recommended to perform the ATF change after travelling 40-60 thousand kilometers, but the older CVT unit, the sooner the replacement should be performed. Opaque ATF is the sign that it is a high time to visit the nearest repair shop.

The structure of CVT 01J is especially sensitive to ATF contamination. The usage of contaminated ATF and clogged filter leads to the premature damage of the transmission components.The common order for the overhaul of this CVT includes the repair kit of gaskets and seals. Another typical spare part for repair of this transmission is an ejection pump.

The ejection pump is made of plastic and operates on the principle of an "atomizer". As in all atomizers, this system is sensitive to cleanness and temperature of the ATF. It gets clogged very quickly and channels wear out. Usage of contaminated and hot ATF leads to low efficiency and such oil should be changed together with other spare parts. Problems with this pump result in some issues with friction elements.

Vulnerabilities of 01J:

The structural design of this CVT exploits a pulling mechanism. Such mechanism exhausts its performance potential quite early, because of stretching loads and frictions, therefore it is changed during each CVT overhaul (after covering 100 thousand kilometers). Usually the pulling plates are replaced together with the pulling mechanism.
The CVT design excludes the possibility of cars towing, otherwise it may lead to lethal consequences for CVT cones and as a result serious problems for transmission itself. Cones are the primary resource of the CVT unit
The control unit of CVT Multitronik VL-300 (with the resource no higher than 100 thousand kilometers) is a common soft spot of electrics for CVTs and 6-speed gearboxes of the first generations.
Another serious problem (less frequently met) is the differential.
It is strongly recommended to pay much attention to the differential condition during the overhaul. If there is a problem with the differential then the gearbox can be considered “dead”. The replacement of 01J differential is a practically impossible task.

Generally, this sophisticated and accurately adjusted gearbox operates quite well in new cars, but after 150-200 thousand kilometers the usage of this transmission reminds a “Russian roulette”.

Which cars run with this gearbox?

Brand	Model	Year	Type	Engine
Audi	A4/A4 CABRIOLET	00-13	CVT F/4WD	L4 1.8L 1.9L 2.0L V6 2.4L 2.5L 2.7L 3.0L 3.2L
Audi	A5/A5 CABRIOLET/A5 SPORTBACK	06-13	CVT F/4WD	L4 1.8L 2.0L V6 2.7L 3.0L 3.2L
Audi	A6	00-13	CVT F/4WD	L4 1.8L 1.9L 2.0L V6 2.4L 2.5L 2.7L 2.8L 3.0L 3.2L
Audi	A7	10-13	CVT F/4WD	V6 2.5L 2.8L V6 3.0L
Audi	A8	03-10	CVT F/4WD	V6 2.8L 3.0L 3.2L

How to repair this transmission (Videos)

Audi cvt 01J atsg

How to repair cvt step by step

Instruction manuals and useful links

Link type	Source	Description
pdf	www.volkspage.net	Design and Function Self-Study Programme 228
pdf	www.at-manuals.com	Variable Automatic Transmission multitronic 01J
pdf	Sonnax	Valve Body Layout 01J
web	Sonnax	VW/Audi 01J/01T Valve Body Identification Guide

Transmission Solenoid and Test Methods

Sat, 13 May 2023 00:00:00 -0700

Transmission Solenoid Test Methods

The variety and shape of solenoids used in modern transmissions changes with each new model. On any rebuild, solenoids are a suspect part and should either be tested and verified for proper operation or replaced. Some shops opt to just replace all the solenoids on the valve body. On some models that makes sense as the replacement solenoids are fairly cost effective. For other models, the cost of either OEM or aftermarket replacement solenoids do make it worthwhile to test and only replace the ones that are worn or faulty.

Figure 1: Hydra-Test HT Sol Solenoid Test Machine

When you test a solenoid, a hydraulic solenoid testing machine with specific adapters for each solenoid is by far the best and most accurate way to test. The Hydra-Test HT Sol has become the industry standard for solenoid testing with a range of adapters that can fit most any solenoid.

The machine comes with full documentation and can guide you through the testing process. For the purpose of this article, I am not going to go into detail on the HT Sol. I want to focus on the basic solenoid and testing terminology such as how you can identify solenoid types, and what kinds of a test methods you would use to accurately test the different solenoids. A good understanding of this will give you a good understanding on what you are trying to achieve when you are testing.

Let us start with some characteristics and terminology used when talking about solenoids.

Solenoid Resistance:

One of the key measurements of a solenoid is to use a multimeter to measure the resistance of the coil. This is a quick and easy check where you can find if you have a short circuit, open circuit, or the possibility of a partially shorted solenoid coil. An important thing to remember is that when you measure the resistance, you are measuring the resistance of the coil, which is a very, very long piece of wire. Unlike a true resistor, where the resistance stays constant over a wide temperature range, the resistance of a solenoid coil will measurably change over temperature (for example between room temperature and 200F).

Normally Open or Normally Closed:

This refers to the hydraulic state of the solenoid when it is off with no electricity applied. A normally open solenoid would allow oil to flow from the inlet to the outlet. A normally closed solenoid would block oil between the input and output. Applying power to the solenoid will switch it to the opposite state. Sometimes these solenoids can be almost identical and will fit in the same hole on a valve body. You can imagine the shift issues that can be caused if this happens so be sure to double check.

Electrical Solenoid Activation:

This refers to how the solenoid is electrically driven when it is energized. The simplest method is to energize it with ignition voltage and allow it to draw full current. The next most common method is to use pulse width modulation (PWM). PWM is pulsing the solenoid on and off many times a second, and the amount of on time vs. the amount of off time is varied to change the amount of average current the solenoid will draw. There is one other method that called peak and hold that I will detail in another article. This method is used by Chrysler and it is similar to PWM but allows the ability to regulate current slightly differently on low resistance solenoids.

Generally, solenoids can be categorized into two types. The first is an on/off where the solenoid either allows full pressure at the outlet or blocks pressure to the outlet. The second is a pressure regulating solenoid where the output pressure from the solenoid is regulated to a desired valve by the varying the current draw of the solenoid.

Figure 2: PWM Definition

On/Off Solenoids:

On/off solenoids are generally smaller in construction.
On/off solenoids have higher resistance and if you measure the resistance it is usually greater than 10 ohms.
Continuous current through these solenoids is around the 0.4-0.7 A and they are designed to handle that amount of current indefinitely.
These solenoids were the primary used as shift and torque converter clutch solenoids in early applications. As transmissions and shift strategies have become more complex, they have been replaced by regulating solenoids.
These solenoids cannot regulate pressure and will apply full pressure to the outlet.

Figure 3: ZF Shift Solenoid | Figure 4: Honda Shift Solenoid

Testing On/Off Solenoids:

Testing of on/off solenoids is straightforward. Pressure should be applied to the inlet and if it is normally closed you should not see pressure at the outlet. Once energized with ignition voltage, you should see pressure at the outlet. For a normally open solenoid, the opposite is true. Pressure applied at the inlet should be seen at the outlet and when it is energized with ignition voltage there should be no pressure at the outlet.

One of the most important aspects of testing an on off solenoid is that there is no leakage through the solenoid when it is in the closed condition. While the solenoid may appear off, wear or cracks internally could allow a small amount of fluid to leak past. If you see leakage, the solenoid should not be reused.

Regulating Solenoids:

These are larger in constructing and incorporate and internal regulating valve.
These have various names such Electronic Pressure Control (EPC), Linear Solenoids, or Trim Solenoids.
These have a lower resistance and if you measure resistance, it is generally less than 10 ohms.
Continuous current through these solenoids is varied and can range from 0 to just over 1 amp.
These solenoids are the most common type used in transmissions today and allow for the smooth application of clutch to clutch shifting as well as the smooth control of the torque converter clutch.

Figure 5: Asian Warner Linear Solenoid | Figure 6: Allison Trim Solenoid | Figure 7: EPC Solenoid

Testing Regulating Solenoids:

Testing of regulating solenoids is a bit more complex. Pressure is applied to the inlet and outlet pressure should be observed as current is varied to the solenoid. Pressure should either increase or decrease with current depending upon if the solenoid is a normally open or a normally closed. These solenoids will have a maximum outlet pressure and applying excessive inlet pressure is not needed and could yield incorrect test results if the solenoid is over pressurized.

The most important aspect when testing a regulating solenoid is that pressure changes smoothly as current is varied and that the outlet pressure is always the same at a given current. Solenoids that are worn will show a difference in outlet pressure at a given current. These solenoids can also stick and have a dead spot where even though the current changes, the outlet pressure remains the same. Lastly if the outlet pressure is not steady and fluctuates rapidly at a given current, then this is an indication that the solenoid may be having trouble regulating.

The best way to visually see how a regulating solenoid is performing is to sweep the current and graph this against pressure. A sweep from zero to max (1-1.3 amps) and back to zero should reveal a smooth graph where pressure changes as the current increases and decreases. One key item to note is that the pressure at a given current value is nearly the same as you increase current and then decrease current to come back to the same current valve. This difference is called hysteresis. There will be some difference of this pressure value (or hysteresis), but it should be minimal. As regulating solenoids wear the hysteresis increases noticeably.

One last item that is important on regulating solenoids is that certain ones have an adjustment screw that allows adjustment of the pressure vs. current relationship, i.e., you will measure more or less pressure for all current values as you adjust the screw in or out. This adjustment screw should not be set to an arbitrary setting, but rather set to match a known “calibrated” solenoid. The TCM in the vehicle has an expectation of what this pressure vs. current relationship should be and you can easily adjust this outside it expected range. When adjusted outside the expected range the solenoid technically functions properly, but the pressure vs. current is now outside of what the TCM expects and this can cause shifting problems and fault codes.

Pressure regulating solenoids that do not have smooth pressure vs. current curves, fluctuate output pressure at a steady current, have large hysteresis values as you sweep them, or cannot be adjusted to match a known good pressure vs. current relationship indicate excessive wear or a faulty solenoid and should not be reused.

Figure 8: Solenoid Pressure and Current Graph from HT Sol

Evolution of Gear Shifting Mechanisms

Fri, 12 May 2023 00:00:00 -0700

Evolution of Gear Shifting Mechanisms

For the first motor-car designs, it was enough to have a single fixed ratio for driving around. But with the rapid march of technologies, it became obvious that developing cars capable of both rapid speed ups and remarkable max speed rates would need some engineering trick of changing the speed relations – the drive ratios – to match the conditions of the moment. Nowadays, there is still no ideal solutions on how to transmit torque from the engine to the drive wheels — actually, there’s not even a universal agreement on the best location for the switching mechanism that controls the ratio changes.

More and more automakers equip their new models with paddle shifting systems – a shifting technology that came from the racing world. But the evolutionary path from the 1-st gear shifting mechanisms to modern paddles shifters is not about a constant onward progress, but rather like a rollercoaster with many ups and downs. The gear shifting mechanism was relocated from the floor to the steering column and the dashboard and then back to the floor many times, and each time reasons for gear shifter repositioning were caused by different trends or the appearance of new technologies.

While some early car models could function with more than one gear ratio, they could not be shifted while running. Everything changed when Louis-René Panhard and Emile Levassor, created a sliding-gear transmission — and a shifting mechanism — for their 1895 Panhard-Levassor.

1895 Panhard-Levassor

By 1904 almost all car manufacturers had started using sliding-gear solutions. Ratios were changed with a long gear lever sticking out of the car’s floor.

For proper gear shifting, the driver certainly needed some specific skills and experience to match the RPM rate and the selected speed. It was quite a challenging task for inexperienced drivers, but it worked, however, this process was often accompanied with substantial grinding of gear teeth. In later years, engineers developed mechanical synchronizers that made the process of ratio changes much easier. The floor-positioning of the lever still prevailed in automotive designs for more than four decades.

However, at that time, this kind of the lever positioning was quite uncomfortable for a passenger in the center of the front seat, therefore in the late 1930s car makers came up with the idea to relocate the shifting mechanism to the steering column. American cars of that time were quite spacious with a front bench seat designed for 3 passengers, so the column shifter seemed like a reasonable solution.

’39 Plymouth column shifter

A column shifter firstly appeared on the American car in 1938, and stayed on the market as a standard shifter option for 4 decades. One of the first column shifters found application on the 1939 Plymouth. Subsequently, this technology was integrated in Chevrolet and Ford models. Eventually, column shifters, also known as “three on the tree”, were considered as an industry standard. But the column shifter reached its prime in the 1940s when automatic cars started conquering the automotive market, and remained in high demand for more than two decades.

3-speed column shifter in a 1951 Ford

By the 1960s, the column shifting technology was on its way to falling out of favor. This gradual change was motivated by 2 main factors — a closer attention to higher performance capacity and the necessity to optimize passenger-cabin designs.

Since column shifters were not easy to operate and unsuitable for racing, the car manufacturers cut holes in sedan floors and installed shifting levers on gearboxes. Pontiac, for instance, provided a special-order 4-speed manual unit with an aftermarket floor shifter, designed by Hurst, in 1961. This measure helped to significantly speed up the process of gear shifting, and “four on the floor” became indispensable for powertrain designs of performance-oriented vehicles.

Interior of the 1966 Pontiac GTO with a four on the floor Hurst shifter

Performance capacity of new models became the main selling point in Detroit, the center of the automotive industry in the US. Evolutionary changes in automotive interior design made bucket seats and center consoles quite popular, so the bench seat was no longer a problem for mounting a floor shifter. By the mid-1980s, column shifters had almost disappeared from road cars sold in the US. However, this system can still be found widely on North American-market.

With the advent of the new millennium, trends in the gear lever positioning changed again. Some, like the shifters in the Fiat 500 and Honda CR-V were located on an extension of the lower dash. At the same time, some Chrysler and Honda minivans were developed with shifting mechanisms mounted well up on the dashboard.

Dashboard gear lever of the ’11 Honda Odyssey

The appearance of “by-wire” technologies, based on electronics rather than on mechanical linkages, motivated some car manufacturers to consider the steering wheel or steering column as more comfortable installation place for gearshift actuators. But experts and common auto enthusiasts still have no common view on this aspect of the automotive design.

How to test a trasmission solenoid?

Thu, 11 May 2023 00:00:00 -0700

How are we testing solenoid?

Here are some common processes used regardless if you are a shop rebuilding a transmission on the bench or are a large reman with assembly lines for high volume production of units. In either case, there is a process of disassembly and determining what parts are good and can be reused, and which ones are bad and must be replaced. Many hard parts that can simply be inspected for wear, cracks, or other damage and determined very quickly if they are useable or not. Many soft parts are automatically replaced as they are not reusable. Between these two types of parts are the ones that require some level of testing to determine if they can be reused or if they need to be replaced. Solenoids are a prime example of such a part since a hydraulic test is required to determine if they are still functioning properly.

When we talk about testing, we not only need to understand why we are testing it, but more importantly, the how do we test it . The “why” is fairly straight forward, as we want to determine if it is still functioning properly and that we can reuse it. The how to test it might not be as clear, and there are multiple methods of how to test, and sometimes opinions on how to test that are not always accurate. The basis of testing involves giving the unit under test some type of a stimulus and measuring the response. Then we examine the response and see if it is within an acceptable range or not to determine if it passes or fails. The proper stimulus and what the acceptable range are is things might get tricky.

So how do we test a solenoid? The obvious answer might be to apply a hydraulic pressure, apply an electrical current, and observe the output pressure. In the case of a variable pressure solenoid, different current points should produce different output pressures and these pressure points should either increase or decrease with current depending upon what type of solenoid it is, right? Well, that answer is partially correct.

I was on site with a customer once and we were testing a Ford 5R55E EPC solenoid. This solenoid is a good basic example of a pressure control solenoid and it is easy to see how as we increase current; the pressure should drop. The controller we had was able to vary the current to the solenoid in steps and you would set it to a value and then check on a pressure gauge the output pressure of the solenoid. I started with it off, then set it at 0.3 amps, then 0.7 amps, then 1.0 amps. The pressure decreased each time. I came back to 0.7, then 0.3, and finally back to 0, and the pressure increased with each test point. At each test point I stopped for about 20 seconds so we could check and read the pressure and discuss. The pressure readings matched what we expected. So, we concluded that this solenoid was fine, operating properly, and ready to be put onto the valve body, right? Wrong!

Increasing Current Steps		Decreasing Current Steps
Solenoid Current	Output Pressure	Solenoid Current	Output Pressure
0.0	90 PSI	1.0	5 PSI
0.3	80 PSI	0.7	32 PSI
0.7	30 PSI	0.3	81 PSI
1.0	5 PSI	0.0	90 PSI

This same machine also had an option where we could increment these current steps over time to “ramp” the current to the solenoid from 0 to a maximum and back to zero. It would then graph the response on the computer screen so we could get a clearer picture of what the solenoid response was. We set the max current to 1.0 amp and our total time for the ramp up and down to about 20 seconds and ran the test. When we did this, we saw a vastly different picture. The solenoid would drop pressure as expected as current increased, however as the current decreased, the solenoid would stick for about 5 seconds at minimum pressure and then snap to about half pressure as we continued decreasing current. This repeated each time we cycled the solenoid as we ran it over and over again. From the graph it was obvious we had a problem, which we could only see as we continually increased or decreased the current, rather than just holding it steady at certain current points. Today, this is easy to see on solenoids machines such as the Hydra-Test HT Sol as this test and graphical method is the basis for how their machine is designed to test. At the time I was working with this customer, this method was more or less only done at large remanufacturers.

But as you can see, this gets to the very root of the how do we test it issue. We also need to understand why one method indicated that everything was fine and the solenoid was working properly, while the other clearly showed us a problem that would cause drivability issues, would give fault codes, and possibly damage to the transmission under certain conditions as our line pressure would be much lower than expected in the unit.

Let us think about how this solenoid functions in the vehicle during normal operation. We want to test in the same way and try to mimic the real-world operating conditions as closely as possible. If we think about an EPC solenoid, especially one that is controlling overall line pressure, how does it operate as the vehicle as it goes down the road? Does it sit at a constant current or is the current constantly varying as the driver changes throttle position, if we are shifting gears, or if we apply the brakes? If you answered that it is constantly varying, you are correct. There may be times when it will be constant (say a long stretch of highway where you keeping a constant speed and throttle), but each time we change an input, it ramps the current up or down over time, just like when we ramped the current and observed it on the graph. If we only look at a few points where the current is constant, we completely miss the bigger picture and the solenoid momentarily sticking before it snaps into place due to wear, internal contamination, or damage.

There are two takeaways from this. The first is that a tool (in this case a solenoid test machine with a variable current and graphing capability) is only as good as the operator and how they are using it. It is important to think about and understand how you are testing. The second takeaway relates to testing equipment. If you have a good handle on how to test you can also verify that the equipment you are purchasing has the features and the ability to test properly. Is the ability to ramp solenoid current and see a resultant graph a standard feature like on the HT-Sol or not? Proper testing yields good results and will save you both time and money, as well as the frustration of chasing a bad part that tested “good” because of incomplete testing.

History of Gearless Transmission Co. and Its Remarkable Transmission Technology

Tue, 09 May 2023 00:00:00 -0700

History of Gearless Transmission Co. and Its Remarkable Transmission Technology

Much like modern automotive trend on shifting from with manual transmissions to more confortable automatics, in the first decade of the last century there was a demand for a semi-automatic transmission that operated without the driver involvement. And automotive engineers of that time had some interesting engineering solutions to offer.

Henry Ford made a fortune on this by developing his version of the planetary transmission for his legendary Model “T”. The Gearless Transmission Co. approached the semi-automatic transmission concept from a different angle and came up with its own designs that found application of several vehicles produced by the company.

This company is known for its Gearless Automobile equipped with the same-named transmission unit. The transmission did not use a flywheel or clutch. Instead the gearless transmission used friction wheels for forward and reverse.

The Gearless was manufactured from 1907 to 1909. In 1907 Gearless automobiles were produced as a Model-50, Model-60 and a Model-75. In 1908 a Gearless produced a 60 horsepower touring car and Greyhound roadster. In addition, a Great Six 75 horsepower touring car and Greyhound Roadster. In 1909, the company produced 12 different vehicles. For its cars the company patented transmission designs.

The gearless transmission gave two speeds without the use of any gears, the high-speed being direct, in which the change-speed elements revolved together as a unit, with no internal friction nor rolling contact. The entire change-speed unit revolved together as a flywheel. It consisted of six large special fiber rolls of conical shape revolving on and in an exterior and interior cone. These two cones co-acted with a sliding, double-faced, solid jaw clutch, which was moved to the extreme forward position to give the low speed and to the extreme rearward position to give the reverse. The internal cone was constantly pressed toward the external cone by means of a spring, so as to always insure “bite” enough to make the six cone rollers revolve without slipping in the low speed and reverse drives.

Patent drawings of the gearless transmission

The Gealess transmission had the advantage of no change-gear friction on the high speed, or direct drive, rolling friction engagement, and rolling friction engagement in low speed and reverse. The coned rollers were held laterally in a cage of large diameter and press against a gray iron cone made fast to the extension of the motor shaft. On their opposite faces they pressed against an internally faced cone, also of gray iron, and which was concentric with the propeller shaft of the car. The cone, roller and cup angles were such that the 3 elements rolled together without any sliding, and hence without sliding friction. To avoid the slipping of the rollers on the cone or in the cup, a heavy spring pressure was applied to the cone cup to force it towards the driving cone, this pressure was sufficient to make it possible for the motor to slide the roller surfaces on the cone or in the cup. Built in two sizes for light and heavy cars, this transmission can be used with either shaft or chain drive. This unique design put less strain on the running gear of a car than many other gear shifting solutions of that time.

Despite the high-quality design and a wide popularity of the Gearless vehicles, with time the company faced significant financial difficulties. After a restructuring in 1908, and the addition of a less expensive four-cylinder car equipped with a standard transmission, the company managed to make it to 1909. However, all measures made to help save the company later turned out to be in vain, and it went out of business that fall.

How Automatic Transmissions Work: Unveiling the Intricate Mechanisms

Thu, 20 Apr 2023 00:00:00 -0700

Automatic transmissions have revolutionized the driving experience, providing seamless gear shifting and effortless maneuverability. But have you ever wondered how these marvels of engineering actually work? In this comprehensive article, we will take a deep dive into the inner workings of automatic transmissions, exploring their key components, the transmission process, and the role of transmission control systems.

Understanding the Basics

Automatic transmissions are complex systems designed to manage gear shifting without manual intervention. Unlike manual transmissions, which require the driver to engage gears using a clutch, automatic transmissions utilize a sophisticated arrangement of components and hydraulic systems to achieve smooth and precise gear changes.

Shift knob of Automatic on the left and Manual on the right

Key Components and Their Functions

Let's explore the essential components that make automatic transmissions function seamlessly:

Torque Converter: The torque converter serves as the connection between the engine and the transmission. It uses a fluid coupling to transmit torque from the engine to the transmission input shaft, allowing the engine to run even when the vehicle is stationary. The torque converter also provides torque multiplication, ensuring smooth power delivery.
Planetary Gearset: The planetary gearset is a fundamental component of automatic transmissions. It consists of a sun gear, multiple planet gears, and a ring gear. By selectively engaging these gears, different gear ratios are achieved, allowing the vehicle to move at various speeds.
Clutches and Bands: Clutches and bands play a crucial role in gear engagement and disengagement. They are controlled hydraulically and are responsible for connecting and disconnecting different sets of gears during gear changes.
Valve Body: The valve body acts as the central control unit of the transmission. It contains a network of hydraulic control valves and solenoids that regulate fluid flow and pressure. By manipulating these valves and solenoids, the transmission can engage or disengage specific clutches and bands, facilitating precise gear changes.

The Transmission Process

Now, let's delve into the intricacies of the transmission process, which ensures smooth gear shifting and efficient power transfer:

Idle and Gear Engagement: When the vehicle is started, the torque converter uses fluid coupling to transmit torque smoothly from the engine to the transmission. As the driver applies throttle and selects a gear, the appropriate clutches and bands engage to establish the desired gear ratio.
Gear Shifting: During acceleration or deceleration, the transmission shifts gears to maintain optimal performance. The process involves the release and engagement of clutches and bands in a precise sequence. The valve body, through its control valves and solenoids, regulates fluid pressure and directs hydraulic systems to execute seamless gear shifts.
Torque Converter Lock-up: To improve efficiency during highway cruising, modern automatic transmissions feature a torque converter lock-up mechanism. When engaged, the lock-up eliminates slippage in the torque converter, establishing a direct mechanical connection between the engine and the transmission. This reduces power loss and improves fuel efficiency.

Transmission Control Systems

To ensure the seamless operation of automatic transmissions, advanced transmission control systems are employed:

Electronic Control Units (ECUs): These sophisticated control units monitor inputs such as vehicle speed, throttle position, and engine load. They use this information to determine the optimal gear selection and timing for gear changes, ensuring smooth and efficient performance.

Transmission Control Module (TCM or TCU)

Sensors and Solenoids: Sensors located throughout the transmission provide crucial data to the ECUs, including transmission fluid temperature, speed sensor readings, and gear position. Solenoids, controlled by the ECUs, actuate hydraulic systems and engage or disengage clutches and bands to execute accurate gear shifts.

Valve Body: It acts as the central control center, orchestrating the intricate process of gear shifting and ensuring smooth and precise operation.

Comprised of a network of hydraulic control valves and solenoids, the valve body is responsible for regulating the engagement and disengagement of clutches and bands, which are crucial for gear changes. By manipulating these valves and solenoids, the transmission can select the appropriate gear ratio based on factors such as vehicle speed, throttle input, and driving conditions.

The valve body receives signals from sensors located throughout the transmission system, including speed sensors, temperature sensors, and throttle position sensors. These inputs provide essential information to the electronic control unit (ECU) that governs the transmission's operation. The ECU uses the data to make real-time decisions regarding gear selection and timing, sending signals to the valve body to actuate the necessary valves and solenoids.

When the driver selects a specific gear or accelerates, the valve body receives the corresponding signals and directs hydraulic pressure to the clutches and bands that need to engage or disengage. This process ensures a smooth and seamless transition between gears, allowing for efficient power transfer and optimum performance.

Additionally, the valve body controls other functions within the transmission, such as line pressure regulation, which ensures proper fluid pressure distribution to different components. It also manages the application of the torque converter lock-up mechanism, which eliminates slippage in the torque converter, improving fuel efficiency during highway driving.

Given its critical role in transmission operation, the valve body requires periodic maintenance and inspection to ensure optimal performance. Over time, debris and contaminants can accumulate within the valves and passages, affecting their functionality. Regular fluid changes and filter replacements are necessary to prevent clogs and maintain the integrity of the valve body.

In summary, the valve body is the control center of an automatic transmission, responsible for regulating fluid flow, pressure, and the engagement of clutches and bands. By precisely directing hydraulic pressure, the valve body enables smooth gear shifting and optimal performance. Its integration with the transmission control systems ensures seamless communication and coordination, resulting in a reliable and efficient driving experience.

Valve Body valves and simplified explanation on how they operate

By understanding the intricate mechanisms at work within automatic transmissions, you can appreciate the engineering prowess behind these remarkable systems. From the torque converter to the planetary gearset and the control systems, each component plays a vital role in delivering a smooth and efficient driving experience. Automatic transmissions continue to evolve, incorporating advanced technologies that enhance performance, fuel efficiency, and overall driving enjoyment.

While we have covered the basics of how automatic transmissions work in this article, it's important to acknowledge that the inner workings of these systems can be quite intricate and complex. Explaining every aspect of automatic transmission operation in simple terms can be challenging.

To provide a more comprehensive and visual understanding, we recommend watching a video that demonstrates the operation of an automatic transmission. Videos can effectively showcase the components, their movements, and the fluid dynamics involved in gear shifting. This visual representation can greatly enhance your comprehension of the concepts discussed in this article.

So, if you're eager to further explore the fascinating world of automatic transmissions, we encourage you to seek out and watch these valuable videos. They will provide you with a more in-depth understanding of the inner mechanisms, making it easier to grasp the complexities of this essential automotive technology.

Video

Torque Converter Tuning: Maximizing Performance and Efficiency

Tue, 21 Mar 2023 00:00:00 -0700

Tuning a torque converter becomes necessary when you seek to unlock the full potential of your vehicle's performance and efficiency. The factory settings of a torque converter may not always cater to your specific driving needs or desired outcomes. By tuning the torque converter, you can optimize various parameters such as stall speed, lockup engagement, and power transfer, resulting in enhanced acceleration, improved fuel efficiency, and better overall drivability. Whether you want quicker launches, increased towing capability, or better fuel economy, tuning your torque converter allows you to customize its behavior to suit your specific requirements. It's a way to fine-tune your vehicle's transmission system and unleash its hidden capabilities, transforming your driving experience to a whole new level of performance and satisfaction.

Why Would Someone Need to Tune a Torque Converter?

When considering torque converter tuning, several key factors should influence your decision-making process. These factors play a crucial role in determining the optimal tuning parameters for your vehicle's torque converter, ensuring that the results align with your specific performance goals and driving requirements. Here are the key factors to consider:

Vehicle Application and Intended Use: The first factor to consider is how you plan to use your vehicle. Are you using it for daily commuting, towing heavy loads, or engaging in racing activities? Each application may require different torque converter tuning parameters to optimize performance, efficiency, and durability.
Engine Characteristics: Understanding your engine's torque curve, powerband, and maximum RPM is essential for torque converter tuning. Matching the stall speed of the torque converter to the engine's characteristics allows for improved power transfer and optimal performance.
Transmission Type and Gear Ratios: The type of transmission in your vehicle, such as automatic or manual, and the gear ratios it offers also influence torque converter tuning. The tuning parameters may differ based on the transmission's design and gear ratios to ensure seamless power delivery and efficient gear changes.
Vehicle Weight and Tire Size: The weight of your vehicle and the size of your tires affect the torque converter's behavior. Heavier vehicles or vehicles with larger tires may require different tuning settings to account for the increased load and potential changes in gear ratios.
Desired Performance Goals: Clearly defining your performance goals is crucial when making torque converter tuning decisions. Whether you prioritize quicker launches, improved acceleration, enhanced fuel economy, or a combination of factors, your goals will help guide the tuning process.
Professional Expertise: While some enthusiasts may have the knowledge and experience to perform torque converter tuning themselves, seeking professional expertise is highly recommended. Transmission specialists and experienced tuners can analyze your vehicle's specific requirements, utilize specialized equipment, and ensure precise tuning for optimal results.

By considering these key factors, you can make informed decisions about torque converter tuning, ensuring that the tuning parameters are tailored to your vehicle's characteristics and aligned with your performance goals. The result will be a torque converter that maximizes power transfer, enhances performance, and provides a thrilling driving experience.

Where and When Tuned Torque Converters are Installed?

Tuned torque converters find applications in various vehicles and scenarios where optimized performance and efficiency are desired. Here are some examples of where tuned torque converters are commonly used:

Racing and High-Performance Vehicles: In the world of motorsports, tuned torque converters are utilized to extract maximum performance from race cars. Whether it's drag racing, road course racing, or off-road competitions, tuned torque converters help provide quick and consistent launches, improved acceleration, and optimal power transfer to the wheels.
Heavy-Duty Towing and Hauling: Vehicles used for towing or hauling heavy loads often benefit from tuned torque converters. By adjusting the stall speed and lockup engagement, torque converters can be tuned to generate higher torque at lower RPMs, enabling improved low-end power and enhancing the vehicle's ability to tow or haul heavy loads.
Off-Road and 4x4 Vehicles: Off-road enthusiasts who engage in challenging terrains and steep inclines can benefit from tuned torque converters. Custom tuning allows for better torque multiplication, providing increased low-end power and improved throttle response, essential for conquering obstacles and maintaining traction in off-road conditions.
Performance Street Cars: Tuned torque converters are popular among enthusiasts who want to enhance the performance of their street cars. By optimizing stall speed and lockup engagement, torque converters can provide improved launch control, better acceleration, and enhanced drivability for spirited driving on the street.
Muscle Cars and Hot Rods: Vintage muscle cars and hot rods can greatly benefit from tuned torque converters. The tuning process can improve low-end torque, allowing for better street manners and more responsive throttle input, while still maintaining drivability in everyday conditions.
Customized Builds and Engine Swaps: When undertaking custom vehicle builds or engine swaps, tuned torque converters are often necessary to ensure compatibility and optimal performance. Engine upgrades, changes in vehicle weight, or modifications to drivetrain components may require torque converter tuning to maximize power transfer and drivability.

It's important to note that tuned torque converters can be tailored to specific vehicle requirements and performance goals. Whether it's for racing, towing, off-roading, or customized applications, tuned torque converters offer a versatile solution to unlock the true potential of various vehicles in different scenarios.

Benefits of Torque Converter Tuning

Improved Torque Multiplication and Power Transfer: By adjusting the stall speed of the torque converter, you can optimize the transfer of power from the engine to the transmission, resulting in enhanced torque multiplication and improved performance during launches and low-speed acceleration.
Enhanced Launch and Acceleration Characteristics: Proper torque converter tuning ensures that the engine operates within its optimal power band, enabling quicker and smoother launches, rapid acceleration, and improved overall vehicle responsiveness.
Increased Efficiency and Fuel Economy: Fine-tuning the torque converter can help reduce engine load and increase efficiency by matching the stall speed to the engine's torque curve. This optimization allows the engine to operate more efficiently, leading to better fuel economy and reduced fuel consumption.
Reduction in Heat Generation and Transmission Wear: A well-tuned torque converter minimizes slippage and reduces heat buildup in the transmission, resulting in decreased wear and prolonging the life of the transmission components.

Factors Considered in Torque Converter Tuning

Stall Speed Adjustment: The stall speed, at which the torque converter begins transferring power, can be adjusted to match the engine characteristics and the vehicle's intended application. Proper matching ensures optimal performance and prevents excessive slippage.
Lockup Engagement: The lockup feature allows for a direct mechanical connection between the engine and transmission, reducing heat and improving efficiency. Determining the ideal lockup engagement point is crucial for maximizing performance and fuel economy.
Converter Design and Materials: Evaluating the design and materials of the torque converter is important for efficiency and durability. Factors such as blade count, impeller design, and the use of high-quality materials impact the converter's performance characteristics.

DIY Torque Converter Tuning

For knowledgeable enthusiasts, basic torque converter tuning techniques can be explored. However, it is important to understand the limitations and potential risks associated with DIY tuning. It is recommended to have a thorough understanding of the vehicle's transmission system and access to the appropriate tools and resources.

For an example, when tuning a torque converter, certain parts and components may need to be installed or upgraded to achieve the desired performance enhancements. Here are some examples of parts that are commonly installed or modified during torque converter tuning:

Torque Converter Clutch (TCC): The TCC is responsible for creating a direct mechanical connection between the engine and transmission, eliminating slippage and improving efficiency. Upgrading the TCC or installing a high-performance aftermarket TCC can enhance lockup engagement and overall transmission performance.
Torque Converter Lockup Controller: A torque converter lockup controller allows for precise control and adjustment of the lockup engagement point. This aftermarket controller provides the flexibility to fine-tune the lockup behavior and optimize performance based on specific driving conditions and requirements.
Torque Converter Impeller and Turbine: Upgrading the impeller and turbine within the torque converter can improve fluid flow and efficiency. Aftermarket impellers and turbines with enhanced design and materials can increase torque multiplication and optimize power transfer, resulting in improved performance and acceleration.
Stator Modification: The stator is another component within the torque converter that can be modified to achieve desired performance characteristics. Stator modifications, such as altering vane angles or installing a high-performance aftermarket stator, can optimize fluid flow and torque multiplication, enhancing overall performance.
Valve Body Modifications: In some cases, modifying the valve body of the transmission may be necessary to accommodate the changes made to the torque converter. Adjusting valve body characteristics, such as shift points and line pressure, can ensure proper coordination between the torque converter and the transmission for optimal performance.
Transmission Cooler: When tuning a torque converter for increased performance, it is important to consider the impact on transmission fluid temperatures. Installing a larger or more efficient transmission cooler can help dissipate heat more effectively, ensuring that the transmission operates within safe temperature ranges even under demanding conditions.

These are just a few examples of the parts that may be installed or modified during torque converter tuning. It is important to consult with experienced transmission specialists or performance shops to determine the specific parts and modifications required based on your vehicle's make, model, and desired performance goals.

Professional Torque Converter Tuning: Consulting with experienced transmission specialists is vital for precise and effective torque converter tuning. These professionals have the expertise and specialized equipment necessary to analyze vehicle specifications, assess performance goals, and tailor the tuning process accordingly.

If you are seeking professional torque converter tuning services, look no further than Go4trans, an online directory of transmission experts and builders. With their comprehensive listing of trusted professionals, you can easily find experienced technicians and specialists who specialize in torque converter tuning.

By turning to Go4trans, you gain access to a network of skilled professionals who have extensive knowledge and expertise in optimizing torque converters for various applications. Whether you need tuning for racing and performance vehicles, heavy-duty towing, or customized builds, the directory provides a wide range of transmission experts who can cater to your specific needs.

Go4trans ensures that the professionals listed in their directory are reputable and have a proven track record of delivering high-quality services. They understand the intricacies of torque converters and can provide tailored solutions to unlock the full potential of your vehicle's performance.

Where to Tune Your Torque converter

Please note that this list is not exhaustive and it's always recommended to conduct your own research and check for the latest information. Here are a few notable companies in the US that can help:

Circle D Specialties (Houston, TX) - Website
Precision Industries (Wake Forest, NC) - Website
Hughes Performance (Phoenix, AZ) - Website
ProTorque Performance Products (Wilmington, NC) - Website
TCI Automotive (Ashland, MS) - Website
B&M Racing & Performance (Chatsworth, CA) - Website
Yank Performance Converters (Southlake, TX) - Website
PTC - Performance Torque Converters (Tyler, TX) - Website
FTI Performance (Deland, FL) - Website
Ultimate Converter Concepts (Knoxville, TN) - Website

These companies have established a reputation in the industry and are known for their expertise in torque converter tuning or providing high-quality tuned torque converters. However, it's important to research and compare their offerings, customer reviews, and services to determine which company best suits your specific needs and requirements.

Conclusion

Torque converter tuning plays a significant role in maximizing the performance and efficiency of a vehicle. With improved torque multiplication, enhanced acceleration characteristics, increased fuel economy, and reduced transmission wear, tuning the torque converter offers a range of benefits. Whether seeking professional assistance or venturing into DIY tuning, it is essential to understand the factors involved and their impact on your vehicle. By investing in torque converter tuning, you can unleash the full potential of your vehicle's powertrain, taking your driving experience to new heights.

Automatic Transmission Upgrades for Racing and Performance Cars

Tue, 21 Mar 2023 00:00:00 -0700

Professional race car owners understand the critical role that automatic transmissions play in achieving optimal performance on the track. Upgrading your automatic transmission can significantly enhance your racing car's capabilities and improve overall performance. In this article, we will delve into the world of automatic transmission upgrades specifically tailored for racing and performance cars. From gear ratios to torque capacity and cooling systems, we will explore the precise and specific upgrades that can give you the competitive edge you need.

In the realm of racing, automatic transmissions are responsible for transferring power from the engine to the wheels efficiently. Every aspect of transmission performance, from gear ratios to shift speeds, plays a crucial role in achieving optimal acceleration, cornering, and overall track performance. Understanding how these factors influence transmission performance is vital for selecting the right upgrades.

Benefits of Upgrading Automatic Transmissions for Racing Cars

Improved Gear Ratios and Shift Speeds: Upgrading your transmission allows you to customize gear ratios to suit specific track conditions. Additionally, faster and more precise shifting capabilities enhance acceleration and maintain momentum through gear changes.
Enhanced Torque Capacity: High-performance clutch packs and bands can handle the increased torque demands of racing engines. Upgrades in this area improve power transfer efficiency and reduce slip, ensuring maximum power reaches the wheels.
Cooling and Heat Dissipation: Intense racing conditions can lead to transmission overheating. Upgrading to high-performance transmission coolers with increased cooling capacity ensures efficient heat dissipation and prevents transmission damage.
Launch Control and Traction Management: Advanced features such as launch control and traction management optimize acceleration off the line, minimizing wheel spin and maximizing power delivery. These upgrades help you achieve faster and more consistent launches.

Automatic Transmission Upgrades for Racing Cars

Performance Torque Converters: Installing high-stall torque converters allows for improved launches and increased torque multiplication. Customized stall speeds based on engine power and racing application ensure optimal performance.
Valve Body Modifications: Upgrading the valve body with a shift kit enables quicker and firmer shifts, reducing shift lag. Manual valve body conversions provide complete control over gear selection, allowing precise gear changes based on racing requirements.
Transmission Cooler Upgrades: High-capacity transmission coolers with increased surface area and auxiliary cooling systems ensure efficient heat dissipation. These upgrades prevent transmission overheating, maintaining optimal performance during intense racing conditions.
Electronic Transmission Control Units (TCUs): Standalone TCUs offer precise control and tuning of transmission parameters. With programmable shift points and torque management, TCUs allow for fine-tuning to optimize performance and achieve consistent shifts.

Rules and Regulations for Automatic Transmission in Racing Vehicles

When it comes to rules and regulations in car racing regarding the automatic transmission, specific requirements can vary depending on the racing series and class. Here are a few examples of rules and regulations that may pertain to the installation and use of automatic transmissions in races:

Transmission Type Restrictions:
- Certain racing classes may mandate the use of a specific type of transmission, such as sequential or dual-clutch transmissions, while prohibiting others.
- Some series may require the use of stock or OEM-based transmissions, limiting modifications and aftermarket upgrades.
Gear Ratio Limitations:
- Racing regulations may impose restrictions on gear ratios, either by specifying a fixed set of gear ratios or limiting the allowable range of gear ratio modifications.
- This ensures a level playing field and prevents teams from gaining an unfair advantage through extreme gear ratio modifications.
Torque Converter Regulations:
- In some racing classes, rules may govern the use of torque converters, such as specifying a maximum allowable stall speed or prohibiting certain types of torque converters altogether.
- These regulations aim to control power delivery and ensure fair competition among participants.
Weight Penalties or Adjustments:
- To balance performance between different cars or classes, racing series may impose weight penalties or adjustments based on the type of transmission used.
- Automatic transmissions, especially those with advanced features, may incur additional weight penalties to maintain parity with manual or other transmission types.
Electronic Control Unit (ECU) Limitations:
- Some racing classes may restrict the use of aftermarket or standalone ECUs for transmission control, mandating the use of factory or spec ECUs.
- This regulation ensures standardized control and prevents teams from gaining an unfair advantage through advanced transmission tuning capabilities.
Transmission Cooling Requirements:
- Racing regulations may specify minimum cooling requirements for transmissions to prevent overheating during races.
- These requirements may include the installation of dedicated transmission coolers or restrict the use of certain cooling methods.

It's important to note that these examples are general in nature, and specific rules and regulations can vary significantly among different racing organizations, series, and classes. Therefore, it's crucial to consult the rulebook and regulations of the specific racing series you participate in to ensure compliance with the transmission-related guidelines. Adhering to these regulations ensures fair competition and a level playing field for all participants.

Selecting the Right Upgrades for Your Racing Car

Consulting with professional transmission builders is crucial when selecting upgrades tailored to your racing goals. Their expertise will help identify the optimal upgrades based on your specific requirements and ensure compliance with racing class restrictions and regulations. When it comes to finding reputable transmission builders, rebuilders, and transmission shops that specialize in transmission tuning, a valuable resource is the online directory at www.go4trans.com.

www.go4trans.com is a comprehensive online directory that connects transmission rebuilders with a network of trusted professionals in the transmission industry. Whether you're looking for expert advice, custom transmission builds, or performance upgrades, this directory provides a curated list of transmission specialists who have extensive experience working with racing and performance cars.

When selecting a transmission builder or shop from www.go4trans.com, take the time to read customer reviews and testimonials to gauge their reputation and the experiences of previous clients. This information can help you make an informed decision and choose a transmission specialist who aligns with your expectations and racing goals.

Installation and Tuning

Professional installation and calibration of the upgraded components are essential for their proper functioning. Skilled transmission specialists will handle the installation process and ensure precise tuning and calibration for optimal performance and reliability.

Maintenance and Care

Regular inspections, fluid changes, and ongoing monitoring of critical parameters are essential for maintaining the upgraded transmission's performance. Regular upkeep and adjustments will help fine-tune the transmission to maintain optimal performance on the track.

Conclusion

Upgrading your automatic transmission for racing and performance cars opens up a world of possibilities. With customized gear ratios, enhanced torque capacity, improved cooling systems, and advanced control features, your racing car can reach new levels of performance. By consulting with transmission specialists, selecting the right upgrades, and investing in professional installation and maintenance, you can unlock the full potential of your racing car's automatic transmission. Embrace the precision and excellence that automatic transmission upgrades bring and take your racing performance to new heights.

What Is a High-Performance Torque Converter

Mon, 20 Mar 2023 00:00:00 -0700

A high-performance torque converter is an upgraded component designed to enhance the performance and efficiency of an automatic transmission system, particularly in high-power or high-stress applications. It is specifically engineered to handle increased torque and power levels while delivering improved drivability and responsiveness.

Source: RevMax

The torque converter is a critical component in an automatic transmission, responsible for transmitting engine torque to the transmission input shaft. It consists of an impeller, turbine, and stator, which work together to transfer power from the engine to the transmission.

Here are some key features and characteristics of a high-performance torque converter:

Increased Stall Speed: The stall speed refers to the speed at which the torque converter begins transferring power from the engine to the transmission. In a high-performance torque converter, the stall speed is typically higher than that of a stock torque converter. This allows the engine to operate at higher RPMs before engagement, resulting in improved launch and acceleration.
Reinforced Components: High-performance torque converters often feature reinforced components to handle the increased stress and torque levels. This can include heavy-duty clutches, stronger impeller and turbine fins, and improved welds for enhanced durability and reliability.
Improved Lock-Up Clutch: The lock-up clutch is responsible for mechanically connecting the impeller and turbine, eliminating slippage and increasing efficiency during highway cruising. In a high-performance torque converter, the lock-up clutch may be upgraded to provide a more solid and reliable connection, reducing heat generation and improving power transfer.
Customizable Options: High-performance torque converters may offer customizable options to suit specific vehicle and performance requirements. This can include selecting different stall speeds, torque multiplication ratios, and even the ability to tune the lock-up engagement characteristics.
Efficient Fluid Dynamics: High-performance torque converters are designed to optimize fluid dynamics for improved efficiency and performance. This involves careful engineering of the impeller, turbine, and stator profiles to minimize turbulence and maximize torque multiplication.

Installing a high-performance torque converter can result in various benefits, such as improved launch and acceleration, reduced slippage, increased torque multiplication, and enhanced overall transmission efficiency. However, it's important to note that the installation of a high-performance torque converter may require modifications to other transmission components and should be performed by experienced professionals to ensure compatibility and optimal performance.

Overall, a high-performance torque converter is a valuable upgrade for individuals seeking to maximize the potential of their automatic transmission, particularly in high-performance or heavy-duty applications where increased torque capacity and improved drivability are desired.

What Is a Transmission Shift Kit?

Mon, 20 Mar 2023 00:00:00 -0700

A shift kit is an aftermarket upgrade designed to improve the performance and shift characteristics of an automatic transmission. It consists of various components, including valve body modifications, springs, and other hardware, that work together to enhance the shifting process.

Shift kit variations

The primary function of a shift kit is to modify the hydraulic pressure and timing within the transmission, resulting in quicker, firmer, and more precise gear changes. Here's a simplified explanation of how a shift kit works:

Valve Body Modifications: The valve body is a crucial component of the transmission that controls the flow and direction of hydraulic fluid. A shift kit typically includes modifications to the valve body, such as installing new valves, springs, or pressure regulators. These modifications alter the behavior of the valve body, allowing for improved shift firmness and timing.
Increased Line Pressure: A shift kit often includes modifications to increase the line pressure of the transmission. Higher line pressure helps ensure that the clutches and bands engage more firmly, reducing slip during gear changes. This results in quicker shifts and improved power transfer.
Improved Shift Timing: The shift kit can also modify the timing of gear changes, allowing for quicker and more precise shifts. By adjusting the hydraulic pressure and timing signals to the clutches and bands, the shift kit can optimize the transition between gears, reducing shift lag and improving overall performance.
Reducing Slip and Heat: Upgrading to a shift kit can also help reduce clutch slippage, which can generate excess heat in the transmission. By improving the firmness of the shifts and minimizing slip, the shift kit helps reduce heat buildup, which is beneficial for the longevity of the transmission.

It's important to note that the installation of a shift kit typically requires mechanical expertise and knowledge of transmission systems. It is recommended to have a professional perform the installation to ensure proper configuration and avoid potential damage to the transmission.

Overall, a shift kit can significantly improve the performance of an automatic transmission by enhancing shift firmness, reducing shift lag, and optimizing power transfer. It is a popular upgrade among enthusiasts and individuals seeking to enhance the driving experience and maximize the potential of their vehicle's transmission.

Upgrading And Tuning Your Transmission: Performance and Efficiency Enhancements

Mon, 20 Mar 2023 00:00:00 -0700

Upgrading your transmission can have a significant impact on both the performance and efficiency of your vehicle. By enhancing various components and systems within the transmission, you can optimize its functionality, improve power delivery, and increase fuel efficiency. In this article, we will explore different performance and efficiency enhancements that can take your transmission to the next level.

If you want to learn basics of transmission tuning, here is an article you have missed

Performance Enhancements for Transmissions

When it comes to enhancing performance, several upgrades can make a noticeable difference. Upgrading to a high-performance torque converter, for example, can improve torque multiplication and enhance acceleration. Installing a shift kit can provide crisper and quicker gear changes, improving overall performance. Upgrading clutch packs and bands can increase power handling capabilities, allowing the transmission to handle higher torque levels. Adding an external transmission cooler can help dissipate heat more efficiently, ensuring optimal performance. Additionally, exploring performance tuning and reprogramming options can optimize shift points and improve power delivery.

In simple terms here are your options:

Upgrading to a high-performance torque converter
Installing a shift kit for improved gear shifting
Upgrading clutch packs and bands for increased power handling
Adding an external transmission cooler for better heat dissipation
Exploring performance tuning and reprogramming options

Efficiency Enhancements for Transmissions

Achieving better fuel efficiency is also possible through various upgrades. Upgrading to a more efficient transmission fluid can reduce friction and improve lubrication, resulting in reduced energy losses. Installing a lock-up torque converter can minimize slippage, increasing efficiency during highway cruising. Adding a transmission temperature gauge can help monitor and maintain the transmission within the optimal temperature range. Exploring aerodynamic modifications, such as improving vehicle airflow and reducing drag, can also contribute to better fuel efficiency. Additionally, considering gear ratio changes can optimize engine RPM and improve overall efficiency.

And again your options are as following:

Upgrading to a more efficient transmission fluid.
Installing a lock-up torque converter for reduced slippage
Adding a transmission temperature gauge for monitoring
Exploring aerodynamic modifications for reduced drag

Considering gear ratio changes for optimal efficiency

Balancing Performance and Efficiency Finding the right balance between performance and efficiency is crucial. Different upgrades offer varying trade-offs, and the choice depends on individual needs and preferences. Consulting with transmission specialists or professionals can help determine the ideal upgrades based on the vehicle's purpose and usage patterns. Evaluating the potential trade-offs between performance gains and fuel efficiency improvements is essential for making informed decisions.

Cost Considerations and Return on Investment Transmission upgrades may involve costs, including the purchase of upgraded components and professional installation. However, it's important to assess the benefits and potential savings over time. Upgrades that improve fuel efficiency can lead to long-term savings on fuel costs. Additionally, optimizing the transmission's performance can extend its lifespan and potentially increase the vehicle's resale value, providing a return on investment in the long run.

Professional Installation and Maintenance To ensure optimal results, professional installation of transmission upgrades is highly recommended. Experts with experience and knowledge in transmission systems can handle the upgrades correctly, maximizing their effectiveness. Regular maintenance, including fluid changes and inspections, is crucial for prolonging the performance and longevity of the upgraded transmission. Consulting with reputable transmission shops or specialists can provide valuable guidance throughout the process.

Maximizing Performance and Comfort: The Power of Automatic Transmission Tuning

Here are some examples of how automatic transmission tuning can make a significant difference:

Shift Timing Optimization: Automatic transmission tuning allows for precise adjustment of shift points and timing. By optimizing these parameters, the transmission can shift gears more quickly and smoothly, resulting in improved acceleration and reduced lag during gear changes. This can enhance the overall responsiveness and drivability of the vehicle.
Customized Shift Patterns: With tuning, it is possible to create custom shift patterns tailored to specific driving preferences or conditions. For instance, a sport mode can be programmed to hold gears longer, providing more power and a sportier driving experience. Conversely, an economy mode can be designed to upshift earlier, promoting fuel efficiency during highway driving. This flexibility allows drivers to tailor the transmission's behavior to their liking.
Increased Towing and Hauling Capability: For vehicles involved in towing or hauling heavy loads, transmission tuning can optimize shift points and torque converter lock-up settings to maximize power and torque delivery. This ensures that the transmission is better suited for the increased load, preventing unnecessary gear hunting and overheating. As a result, the vehicle becomes more capable and efficient when towing or carrying heavy loads.
Enhanced Downshifting and Kickdown Performance: Automatic transmission tuning can improve the downshifting and kickdown response. This means that when additional power is required, such as during overtaking or merging onto highways, the transmission will downshift more quickly and smoothly, providing a surge of power on demand. This improves safety and maneuverability in critical driving situations.
Adaptive Shift Control: Some advanced transmission tuning systems can adapt to the driver's behavior and driving conditions. By continuously monitoring variables such as throttle input, vehicle speed, and road conditions, the tuning software can adjust shift patterns and timing in real-time. This adaptive shift control ensures optimal performance and efficiency across various driving scenarios.
Limiting Torque Converter Slip: Tuning can also minimize torque converter slip, which is the loss of power that occurs during the engagement of the torque converter. By reducing slip, more power is efficiently transferred to the wheels, resulting in improved acceleration and fuel economy.
Improved Fuel Efficiency: Through transmission tuning, gear ratios can be optimized to match the engine's powerband and load requirements more precisely. This can lead to improved fuel efficiency by reducing unnecessary revving or gear changes, enabling the engine to operate within its most efficient range more consistently.

It is important to note that automatic transmission tuning should be performed by experienced professionals or using reputable tuning software to ensure proper calibration and avoid adverse effects on the vehicle's reliability. With the right tuning approach, automatic transmissions can be optimized to provide smoother shifts, improved performance, and a more enjoyable driving experience.

Conclusion

Upgrading your transmission can unleash its full potential in terms of performance and efficiency. By exploring various enhancements, such as upgrading torque converters, installing shift kits, improving cooling systems, and optimizing gear ratios, you can transform your driving experience. Finding the right balance between performance gains and fuel efficiency improvements is key, and consulting with professionals can help make informed decisions. With proper installation and maintenance, upgrading your transmission can offer long-term benefits, enhancing your vehicle's performance and extending its lifespan.

Transmission Rebuild vs. Replacement: Which is Better?

Fri, 17 Mar 2023 00:00:00 -0700

When faced with major transmission issues, such as erratic shifting, slipping gears, or transmission failure, car owners are often confronted with a crucial decision: should they opt for a transmission rebuild or a complete replacement? This article aims to provide a comprehensive guide to help car owners make an informed choice between transmission rebuild and replacement.

Understanding Transmission Rebuild

A transmission rebuild involves disassembling the existing transmission, inspecting and replacing worn-out or damaged components, and reassembling the transmission with new parts. While similar to transmission repair, a rebuild goes beyond simple fixes and addresses more extensive issues.

The process of a transmission rebuild requires expertise and specialized knowledge. Skilled technicians carefully diagnose the transmission, remove it from the vehicle, and meticulously examine each component for signs of wear or damage. They then replace worn-out parts with either original equipment manufacturer (OEM) parts or high-quality aftermarket components. The transmission is reassembled and reinstalled, ensuring proper function and performance.

There are several benefits to opting for a transmission rebuild. Firstly, it is a cost-effective solution compared to a complete replacement. Rebuilding the transmission allows you to retain the original transmission casing and certain components, which can help save on costs. Additionally, preserving the original transmission can maintain the integrity of your vehicle, especially if it is a classic or vintage model. Moreover, some rebuilders offer performance upgrades during the process, enhancing the overall performance and durability of the transmission.

However, there are a few downsides to consider. One significant drawback is that a transmission rebuild is a time-consuming process. It requires careful disassembly, inspection, and reassembly, which can prolong the time your vehicle spends in the repair shop. Additionally, while reputable rebuilders provide warranties on their work, these warranties are typically more limited compared to those offered with a complete transmission replacement.

Considering the potential downsides of a transmission rebuild, such as the time-consuming process involved, an alternative option to consider is installing a remanufactured transmission. While a rebuild can take a significant amount of time due to the disassembly, inspection, and replacement of specific components, a remanufactured transmission offers a more convenient solution.

A remanufactured transmission provides several advantages over a rebuild. Firstly, it is a complete overhaul of the entire transmission, ensuring that all components are thoroughly inspected, cleaned, and replaced as necessary. This comprehensive approach reduces the likelihood of future issues and provides a more reliable long-term solution.

Additionally, remanufactured transmissions are rebuilt to meet or exceed original equipment manufacturer (OEM) specifications. This means that they are engineered to perform at the same level as a brand-new transmission. High-quality remanufactured parts are utilized, ensuring durability, efficiency, and optimal performance.

Transmission rebuild and transmission remanufacturing are two different approaches to addressing transmission issues. While both involve restoring a transmission to a functional state, there are distinct differences between the two processes.

Source: AARROW Transmissions

Transmission Remanufacturing

Transmission remanufacturing, on the other hand, involves a more extensive process. It goes beyond simply replacing faulty components and focuses on rebuilding the entire transmission to meet or exceed original equipment manufacturer (OEM) specifications. Remanufacturing involves dismantling the transmission, cleaning and inspecting all components, replacing worn or damaged parts, and reassembling the transmission with both new and remanufactured parts.

Key characteristics of transmission remanufacturing include:

Complete Overhaul: The entire transmission is disassembled, inspected, and cleaned. All components, including gears, clutches, seals, and bushings, are examined and replaced as necessary.
OEM Standards: Remanufacturing is done to meet or exceed OEM specifications. The use of high-quality remanufactured parts ensures reliability and performance.
Testing and Quality Control: Remanufactured transmissions undergo rigorous testing to ensure proper functionality and adherence to industry standards before being made available for installation.

The main difference between transmission rebuild and remanufacturing lies in the extent of the process. A rebuild focuses on repairing specific issues and replacing faulty components, while remanufacturing involves a comprehensive overhaul of the entire transmission, aiming to bring it back to a like-new condition.

When considering transmission repair options, it is essential to consult with a reputable transmission specialist who can assess the specific needs of your vehicle and recommend the most suitable approach—whether it be a rebuild or remanufacturing—to ensure optimal performance and longevity of your transmission.

Source: Aviation Pros

Exploring Transmission Replacement

Transmission replacement involves completely removing the malfunctioning transmission and installing a new or remanufactured unit. This process provides a quick and immediate solution to severe transmission issues that cannot be adequately addressed through a rebuild.

During a transmission replacement, the old transmission is carefully disconnected and removed from the vehicle. A new or remanufactured transmission unit, which has been thoroughly inspected and rebuilt by professionals, is then installed in its place. This replacement typically comes with a warranty that provides coverage and peace of mind.

One of the significant advantages of transmission replacement is its ability to provide an immediate fix for severe transmission problems. If the existing transmission has suffered extensive damage or if the vehicle is older with high mileage, replacement may be the most viable option. Additionally, the warranty coverage that comes with a replacement transmission offers added protection and reassurance.

However, it is important to note some potential drawbacks of transmission replacement. Firstly, it tends to be more expensive compared to a rebuild. The cost of a new or remanufactured transmission, along with the labor involved in the replacement process, can significantly increase the overall repair bill. Moreover, there is a slight risk of compatibility issues, especially with older vehicles or those with specific transmission configurations. Lastly, a transmission replacement may not address underlying problems in other components of the vehicle's drivetrain.

Factors to Consider when Making a Decision

When deciding between a transmission rebuild and a replacement, several factors should be taken into consideration:

Severity of transmission issues: Evaluate the extent of the transmission damage and whether it can be adequately repaired through a rebuild.
Age and mileage of the vehicle: Older vehicles with high mileage may benefit from a replacement, while newer vehicles may be better suited for a rebuild.
Budgetary considerations: Determine your budget and compare the cost of a rebuild and replacement to make an informed financial decision.
Availability of replacement transmissions: Ensure that suitable replacement transmissions are readily available for your vehicle make and model.
Long-term goals for the vehicle: Consider your plans for the vehicle. If you intend to keep it for an extended period, a rebuild may be more appropriate, while a replacement could be ideal if you plan to sell or upgrade in the near future.

Making a Decision

If you are in the process of deciding whether to replace or repair your transmission, utilizing the online resource Go4trans can be immensely helpful. Go4trans provides a comprehensive directory of local transmission rebuilders and transmission shops that specialize in transmission repairs, rebuilds, and replacements.

By accessing Go4trans, you gain access to a vast network of experienced professionals who can assess the condition of your transmission, provide expert advice, and offer tailored solutions to address your specific needs. Whether you require a transmission rebuild or a complete replacement, the directory helps you connect with reputable rebuilders and shops that have a track record of delivering quality workmanship and customer satisfaction.

The advantage of using Go4trans is the convenience it offers. Instead of spending countless hours searching for reputable rebuilders or shops in your area, Go4trans provides a centralized platform where you can easily browse and compare the services, expertise, and customer reviews of different professionals. This allows you to make an informed decision based on the reputation and experience of the rebuilders or shops listed on the platform.

Furthermore, Go4trans offers the convenience of purchasing a transmission online. If your transmission requires a complete replacement, the platform provides a range of options to choose from, including remanufactured transmissions, used transmissions, and even performance upgrades. You can browse through the available inventory, compare prices, specifications, and warranty information, and make a purchase directly through the platform. This streamlined process saves you time and effort while ensuring that you have access to high-quality transmissions that meet your specific requirements.

Using Go4trans not only simplifies the process of finding reputable transmission professionals but also enhances your overall experience by providing a one-stop platform for all your transmission needs. Whether you are seeking a repair, rebuild, or replacement, the directory's extensive network of rebuilders, transmission shops, and online transmission sellers ensures that you have access to reliable options that can meet your unique needs and budget.

Conclusion

In conclusion, when faced with major transmission issues, the decision to rebuild or replace depends on various factors. Consulting with a professional transmission specialist is crucial in assessing the specific situation and determining the most suitable course of action. It is important to carefully consider the severity of the issues, the age and mileage of the vehicle, budgetary constraints, the availability of replacement transmissions, and your long-term goals for the vehicle.

Whether you choose a transmission rebuild or replacement, it is essential to rely on reputable professionals. Go4trans, an online directory of transmission experts and transmission shops, can assist in finding reliable professionals who specialize in transmission repair and replacement. Their expertise and experience will ensure that your transmission issues are addressed effectively and efficiently, getting your vehicle back on the road with optimal performance and reliability.

Automatic Transmission Troubleshooting Guide

Fri, 17 Mar 2023 00:00:00 -0700

When it comes to the smooth operation of your vehicle, the automatic transmission plays a vital role. However, like any mechanical component, transmissions can experience issues over time. Being able to troubleshoot these problems is crucial for maintaining the performance and longevity of your vehicle. In this article, we will provide you with a comprehensive automatic transmission troubleshooting guide to help identify and resolve common issues.

Common Symptoms and Indications of Transmission Issues

Before diving into troubleshooting, it's important to familiarize yourself with common symptoms that indicate potential transmission problems. These include delayed engagement or slipping gears, erratic shifting or harsh transitions, leaking fluid or a burning smell, and strange noises or vibrations. Recognizing these signs early on can help prevent further damage and costly repairs.

Diagnostic Tools and Procedures

To effectively troubleshoot automatic transmission problems, you need the right tools and procedures. On-board diagnostics (OBD-II) and error code scanning can provide valuable information about specific issues. A visual inspection of transmission components, checking fluid levels and condition, and test driving while monitoring performance are all essential steps in the diagnostic process.

Diagnosing an automatic transmission problem using a diagnostic tool can provide valuable insights into the specific issues affecting your vehicle. Here are a few examples of how a diagnostic tool can help identify transmission problems:

OBD-II Error Code Scanning: One of the primary functions of a diagnostic tool is to read error codes stored in the vehicle's onboard computer system. These codes provide specific information about the areas of the transmission that are experiencing issues. For example, if the tool retrieves a code such as P0700 (Transmission Control System Malfunction), it indicates a general problem with the transmission control module. This allows you to focus your troubleshooting efforts on the control system.
Live Data Monitoring: Many advanced diagnostic tools can also display live data from various sensors and components in real-time. This feature enables you to observe the behavior of the transmission while the vehicle is running. For instance, you can monitor the vehicle speed sensor (VSS) readings, transmission fluid temperature, shift solenoid operation, and other relevant parameters. If you notice abnormal readings or inconsistencies, it can help pinpoint the specific area of concern.
Transmission Line Pressure Testing: Some diagnostic tools allow for transmission line pressure testing. This involves connecting the tool to the transmission's pressure ports and monitoring the pressure levels during different driving conditions. Deviations from the manufacturer's specified pressure ranges can indicate problems with the pump, valves, or clutch packs.
Resetting Adaptations: Certain diagnostic tools offer the ability to reset transmission adaptations. Over time, the transmission control module adapts its shift patterns and pressure settings based on driving habits and component wear. However, these adaptations can become skewed, resulting in poor performance. Resetting adaptations can help the transmission relearn and readjust to optimize its operation.
Data Logging and Analysis: Advanced diagnostic tools may provide data logging capabilities, allowing you to record specific transmission parameters over a period of time. This recorded data can be later analyzed to identify patterns, irregularities, or trends that may point to underlying transmission issues.

Remember, using a diagnostic tool requires proper knowledge and interpretation of the obtained data. If you're unsure about the results or need assistance in analyzing the information, it's recommended to consult with a professional transmission technician who has experience in interpreting diagnostic tool outputs. They can provide expert guidance and help you accurately diagnose and resolve the transmission problem.

Troubleshooting Common Transmission Problems

Low fluid level or leaks are a common culprit behind transmission issues. Regularly checking fluid levels and addressing any leaks can prevent damage to internal components. Worn or damaged clutch plates can cause slipping or harsh shifting. Understanding the symptoms and appropriate remedies for clutch-related problems is crucial. Faulty solenoids or sensors can disrupt the transmission's operation. Troubleshooting and replacing these components may be necessary. Torque converter problems, such as lockup issues or overheating, require proper diagnosis and resolution. Valve body malfunctions can lead to shifting problems, and identifying the specific issue can help determine the appropriate fixes.

DIY Troubleshooting Tips

While some transmission issues may require professional assistance, there are several troubleshooting tasks you can perform yourself. Fluid and filter replacement, adjusting transmission bands or cables, checking electrical connections, and performing regular maintenance are all within the realm of DIY troubleshooting. These tasks can help maintain the health of your transmission and prevent minor issues from escalating.

If you are planning to repair your transmission on your own, it is important to have access to technical information and instruction manuals specific to your transmission model. Fortunately, there are resources available to help you with this endeavor. One such valuable resource is Go4trans, an online catalog that provides a wealth of information related to transmission rebuilding.

Go4trans offers a comprehensive collection of data, parts, hints, and tips specifically tailored for professionals and garage shops involved in transmission repairs. Whether you are looking for detailed diagrams, step-by-step instructions, or troubleshooting guidance, Go4trans can be a valuable tool in your transmission repair journey.

The catalog provides a vast range of technical information, including transmission specifications, torque converter details, valve body layouts, and wiring diagrams. This comprehensive data ensures that you have access to the most accurate and up-to-date information for your specific transmission model.

In addition to technical information, Go4trans also offers a wide selection of transmission parts and components. Their extensive inventory includes everything from individual transmission components to complete rebuild kits. This allows you to source the necessary parts conveniently from a single platform, ensuring compatibility and quality for your transmission repair project.

When to Seek Professional Help

Certain transmission problems are complex or require specialized knowledge and tools to diagnose and repair. If you lack experience or the necessary equipment, it's best to consult a professional transmission specialist. Additionally, considering warranty or insurance coverage is important when determining whether to seek professional assistance.

Conclusion

A properly functioning automatic transmission is crucial for a smooth and enjoyable driving experience. By familiarizing yourself with common transmission issues and following this troubleshooting guide, you can effectively identify and resolve problems before they escalate. Remember to perform regular maintenance and seek professional help when necessary. Taking care of your automatic transmission will ensure its longevity and keep your vehicle running smoothly for years to come.

Problems Identifying Transmission Model

Tue, 14 Mar 2023 00:00:00 -0700

Problems Identifying Transmission Model

Car transmission model identification can become a complicated task, especially when dealing with transmissions that have various modifications. It's not uncommon to come across transmissions that are challenging to identify due to their unique specifications and variations. For instance, some transmissions may have different sub-models or versions depending on the vehicle's year, trim level, or engine configuration. This complexity can make it difficult to pinpoint the exact transmission model without the right resources.

Furthermore, certain transmissions may lack clear identification markings or labels, making the identification process even more challenging. In such cases, relying on external sources or expert knowledge becomes crucial to accurately determine the transmission model. This is where go4trans.com's online tool can be immensely helpful. By leveraging their extensive database and expertise, they can assist in identifying transmissions that are notoriously hard to pinpoint.

Whether you're dealing with a transmission that has multiple variations, obscure markings, or limited documentation, go4trans.com's tool can be your go-to resource. It provides valuable information and comprehensive details on a wide range of transmissions, including those that are notoriously difficult to identify. With their assistance, you can navigate the complexities of transmission model identification and ensure accurate and reliable results.

Common Challenges in Identifying Automatic Transmission Models:

1. Lack of visible identification markings on the transmission case:

Automatic transmissions often come without visible identification markings or labels on their cases. This absence can make it difficult to determine the exact model, especially for those unfamiliar with transmission designs. Vehicle owners and mechanics may face frustration when trying to identify the specific transmission installed in a vehicle.

2. Faded or illegible identification tags or labels:

Over time, the identification tags or labels on automatic transmissions can become faded, worn, or illegible due to exposure to environmental factors or regular wear and tear. This can further complicate the identification process, as the crucial information needed to determine the transmission model may no longer be readable.

3. Variations and inconsistencies in transmission models across vehicle years and trims:

Automakers often introduce variations in transmission models across different vehicle years and trims. These variations can include changes in internal components, gear ratios, or even the entire transmission design. As a result, accurately identifying the specific transmission model for a particular vehicle year and trim can be challenging.

Go4trans Transmission Identifier

Looking to identify your car's transmission model? Our online tool at go4trans.com can help! Simply select your car's brand and model, and our tool will provide accurate and detailed information about your transmission. Visit go4trans.com today to unlock the secrets of your car's transmission!Looking to identify your car's transmission model? Visit go4trans.com and use our online tool. It's quick, easy, and accurate. Find out all about your car's transmission with just a few clicks!

Solutions for Identifying Your Automatic Transmission Model:

1. Researching the vehicle manufacturer's documentation:

One of the initial steps in identifying the transmission model is to consult the vehicle manufacturer's documentation. The owner's manual or service booklet may provide relevant information about the transmission used in the specific vehicle. Additionally, many manufacturers offer online resources or websites that provide detailed specifications and identification guides for their transmissions.

2. Utilizing online databases and VIN decoding services:

Online databases and Vehicle Identification Number (VIN) decoding services can be valuable tools in identifying automatic transmission models. Reputable websites and platforms provide comprehensive databases where users can input the VIN to retrieve information about the vehicle, including transmission details. VIN decoding tools help decode the VIN and extract transmission-related information, aiding in accurate identification.

Seeking Professional Assistance:

When faced with challenges in identifying the transmission model, seeking professional assistance is highly recommended. Qualified mechanics or transmission specialists possess the expertise and experience to identify various transmission models accurately. Locating reputable automotive repair shops or dealerships and consulting their technicians can provide valuable guidance in identifying the specific transmission model.

Professional inspection or diagnostic services can be employed to accurately determine the transmission model

How To Improve Automatic Transmission Shifts?

Mon, 06 Feb 2023 00:00:00 -0700

This article discusses how automatic transmissions work, how to improve shifts, and the potential for transmission damage. - Automatic transmissions reduce the number of cars transmission components, which reduces automatic transmission and transferring engine power to the drivetrain. To improve shifts, one should reduce higher engine speed when torque increases and maintain an optimum RPM. Revolutions per minute (RPMs) are a measure of how quickly your transmission is transferring power from the engine to the wheels.

Improving automatic transmission shifts requires understanding how the RPMs increase and decrease, as well as how to reduce lower gear ratios for certain driving conditions. The first step in improving automatic transmission shifts is to shut off your car’s engine and turn your transmission to the “Neutral” position. This will stop power from being transferred from the engine to the wheels, which makes it easier to shift between gears. Speed shifting can also be helpful when improving automatic transmission shifts. This involves shifting up or down quickly, allowing for higher torque output with less time spent in lower gear ratios. By doing this, you can reduce the output speed of its engine while still giving better control over acceleration and deceleration. Another way to improve automatic transmission shifts is by increasing Rpms before shifting into a lower gear. This will ensure that the Rpms increase quickly as soon as you shift, giving you better control over accelerating or decelerating your vehicle.

Improving automatic transmission shifts can be accomplished by ensuring that the delayed low fluid causes and transmission failure are addressed. Shifts slippage can also be caused by a lack of proper maintenance on your automatic transmissions, whether gas or diesel. Delayed engagement troubles can be alleviated by making sure your diesel per mile and gears are correctly adjusted and maintained. Additionally, making sure your transmission fluid is at the correct level is important, as an improper level can cause delayed shifting or harsh engagement shifts. Using your engine to its fullest potential by not using more gas than necessary will also help avoid rough shifting. If you take care of all these things, you will have a proper transmission that shifts smoothly without any issues.

To improve automatic transmission shifts, it is important to check for any signs of transmission gearbox failure, fluid clutch slipping, or slipping shift cables. If these problems are not addressed properly, it can lead to breaks in the transmission fluid and overheated transmission fluid. This can cause several problems such as worn out clutches and gears.

To improve automatic transmission shifts, it is important to maximize the transmission life. This can be done by changing the transmission fluid regularly. High-quality synthetic fluids are ideal as they provide extra protection against heat and wear. The fluid should also be warmed up before use to ensure smooth and efficient work. Additionally, transmission liquid should be able to resist heat buildup while providing proper lubrication during major shifts. Poor cold flow properties can also lead to hard shifts, so using fluids designed for colder temperatures will help reduce this issue. All of these steps will help improve shift quality and provide better quality transmissions that will last longer.

Exact transmission maintenance intervals should be followed as prescribed in your vehicle's owner's manual. Regular transmission services such as replacing the fluid and eliminating shifting problems should be done at least every 30,000 miles or more often if you do a lot of towing or off-roading. Jiffy Lube can provide these services using the Mopar type of fluid for your particular make and model.

Improving automatic transmission shifts is easy when following a factory recommended maintenance schedule. Doing regular maintenance and making basic upgrades can help keep the wear on your vehicle's transmission to a minimum. Cars transmission fluid needs to be changed at manufacturers recommended intervals. Making sure that you are taking care of your factory engine and transmission will ensure better response from your cars shifting. This includes checking the level of the fluid often and making sure there are no leaks. Changing the fluid regularly will make sure it lasts longer, providing smoother shifts for years to come.

If you’re looking to improve automatic transmission shifts, there are few things you can do. Firstly, changing your driving habits can greatly improve the performance of your car. Secondly, making sure that you have the correct size tires for your vehicle is important. Different sized tires affect how the transmission operates and can cause issues with shifting and acceleration. Thirdly, having proper alignment on your axles and driveshafts are also important in making sure that your transmission shifts properly. Additionally, upgrading the transmission or even having a transmission upgrade installed can drastically improve its performance as well.

One of the main upgrades is to use an auto transmission, which engages and disengages the clutch hydraulically. This helps shift gears more smoothly and quickly. When in first gear, the transmission output shaft is connected to the clutch pack, which is then shifted into a car's drivetrain when the driver wants to move. The shaft route power from the engine to the drivetrain and starts car moving when connected. An electronic control unit sends transmission control module commands to a hydraulic valve body which squeezes hydraulic pressure onto clutches that then connect with a driver’s clutch band and connect with engine power.

To improve automatic transmission shifts, learn to engage the transmissions overdrive gear, understand and learn about adaptive transmissions, learn your driving habits and engage the transmission control module. Speed shifters can be used to adjust shifts which will help maintain a steady speed while cruising in your car. The transmission control module controls solenoids which helps in controlling the position of cars speed.

It is used in most automatic transmissions and is designed to improve the performance of most automatic transmissions. Diesel automatic transmissions can also be improved by controlling manual transmission with the help of a torque converter. Manual downshifting can be used to control shifts in addition to changing transmission fluid, transmission types and other areas. Automatic transmissions should also be used to control top speed and high speeds as well as clutches depending on the type of car you have. The fluids should also be checked regularly for high speed driving and other areas. By using vacuum, it can help with better shifting performance during acceleration or deceleration which will help improve automatic transmission shifts.

It is important to understand how your car's transmission behaves and what type of transmission liquid it uses. This way you can avoid making mistakes that could add unnecessary wear and tear to your vehicle. Professionals recommend keeping an eye on the way your transmission condition changes over time, going for regular check ups with a trusted mechanic.

Transmission Flush Cost

Mon, 06 Feb 2023 00:00:00 -0700

Maintaining a healthy transmission is crucial for the smooth operation and longevity of your vehicle. Regular maintenance, such as a transmission flush, plays a vital role in preserving its performance. In this article, we will delve into the cost of a transmission flush, exploring various factors that influence the expenses involved and providing insights into the DIY vs. professional options.

What is a Transmission Flush?

A transmission flush is a process that involves replacing old transmission fluid with new fluid to remove debris, contaminants, and sludge buildup. By flushing the system, you can enhance the overall performance and lifespan of your transmission.

Transmission flush equipment / Flushed out ATF looks totally bad

The main operational principle of a transmission flush equipment is to remove the old transmission fluid from the system and replace it with fresh fluid. This process is typically achieved through a series of steps:

Connection: The equipment is connected to the transmission system using hoses that are attached to the inlet and outlet ports of the transmission.
Fluid Exchange: The machine uses its pump to circulate new transmission fluid into the transmission system while simultaneously extracting the old fluid. This exchange process helps remove contaminants, debris, and sludge that may have accumulated in the system over time.
Pressure and Flow Control: The equipment maintains controlled pressure and flow rates during the fluid exchange. This ensures that the new fluid reaches all areas of the transmission system, including the cooler, torque converter, and valve body, effectively flushing out the old fluid and contaminants.
Filter Replacement (optional): Some transmission flush machines have the capability to replace the transmission filter as part of the process. This involves removing the old filter and installing a new one to ensure optimal filtration of the fresh fluid.
Complete Fluid Exchange: The equipment continues the fluid exchange process until the old fluid has been thoroughly flushed out, and the new fluid has replaced it. This helps to improve the overall performance and longevity of the transmission system.

It is important to note that different transmission flush machines may have variations in their specific operational features and procedures. Manufacturers may incorporate additional functionalities or proprietary technologies to enhance the efficiency and effectiveness of the fluid exchange process.

Factors Affecting Transmission Flush Cost:

Type of Vehicle: The make, model, and age of your vehicle can impact the cost of a transmission flush. High-end or luxury vehicles often require specialized transmission fluid or have more complex systems, leading to higher costs.
Type of Transmission Fluid: Different vehicles require specific types of transmission fluid, and the cost of these fluids can vary. Some vehicles may necessitate synthetic or specialty fluids, which can be more expensive than conventional options.
Labor Costs: Labor charges for a transmission flush can differ based on the service provider and location. Factors such as shop rates and the level of expertise required can influence the overall cost.
Location: Regional variations can affect the cost of a transmission flush. Urban areas or areas with a higher cost of living might have higher service charges compared to rural locations.
Additional Services or Repairs: If additional services or repairs are required during the transmission flush, such as replacing the filter or gasket, the overall cost will increase. It's important to consider these potential expenses.

Average Cost Range for Transmission Flush: The cost of a transmission flush can vary significantly based on the factors mentioned earlier. However, to provide a general idea:

Low-end cost estimates: $75 to $150
Mid-range cost estimates: $150 to $300
High-end cost estimates: $300 to $500 or more

DIY vs. Professional Transmission Flush:

Performing a transmission flush yourself is a cost-saving option, but it comes with risks. DIYers should have the necessary knowledge, tools, and access to quality fluids. Alternatively, opting for a professional transmission flush ensures expertise, proper equipment, and potential warranties for the service. It's essential to weigh the pros and cons based on your skill level and resources.

Additional Considerations:

Transmission Flush Alternatives: In some cases, a transmission flush may not be necessary or suitable. Your service provider can recommend alternatives, such as a fluid change or a fluid exchange, which may be more appropriate for your vehicle.
Choosing a Reputable Service Provider: When seeking professional assistance, it's crucial to select a reputable service provider with experience in transmission maintenance. This ensures quality workmanship and reliable service.
Regular Maintenance Tips: To avoid costly repairs, adhere to regular maintenance schedules, including fluid checks, filter replacements, and following your vehicle manufacturer's guidelines.

Conclusion:

Maintaining a healthy transmission is vital for the overall performance and longevity of your vehicle. Understanding the factors that influence the cost of a transmission flush empowers you to make informed decisions. Whether you choose a DIY approach or seek professional assistance, regular maintenance and budgeting for transmission flushes are essential investments that can save you from expensive repairs down the road.

Manual Transmission Types: Exploring the Different Designs

Mon, 06 Feb 2023 00:00:00 -0700

Manual transmissions have long been an essential component of the automotive industry, providing drivers with a direct and engaging connection to their vehicles. Unlike automatic transmissions, which rely on complex hydraulic systems, manual transmissions require drivers to manually engage and disengage the gears, offering enhanced control and a more immersive driving experience. The act of shifting gears, feeling the mechanical connection, and being in full command of the powertrain contributes to the joy and art of driving.

In this article, we will delve into the world of manual transmissions and explore the various types available. From traditional non-synchronized transmissions to modern automated manual transmissions, each design offers unique characteristics and benefits.

Non-Synchronized Manual Transmissions

Non-synchronized transmissions, also known as "crash" transmissions, were the early iterations of manual transmissions. They lack a synchronizer mechanism, requiring drivers to rev-match and time their gear shifts accurately. These transmissions are more common in older vehicles and some specialty applications.

Driving a bus with non-synchronized gearbox

Sliding-Gear (Crash) Transmissions

Sliding-gear transmissions were the earliest form of non-synchronized transmissions. They employ a sliding collar mechanism that physically moves gears into place during shifting. While these transmissions offer simplicity and durability, they require skillful gear engagement and can produce gear grinding if not properly synchronized.

While sliding-gear (crash) transmissions are not commonly used in modern auto sports, they have played a significant role in the history of motorsports. In the early days of racing, before the advent of synchronized transmissions, sliding-gear transmissions were the norm.

Auto racing pioneers relied on sliding-gear transmissions for their simplicity, durability, and ability to handle the high torque demands of racing engines. These transmissions were commonly found in early race cars, including those participating in events like the Indianapolis 500 and early Formula racing.

Sliding-gear transmissions required skillful and precise shifting techniques from the drivers. In racing scenarios, where split-second decisions and quick gear changes can determine the outcome, drivers had to master the art of double-clutching and timing their shifts to minimize power loss and maximize acceleration.

Double-Clutch Transmissions

Double-clutch transmissions introduced a significant advancement in manual transmission technology. They utilize two separate clutches, one for odd gears and another for even gears. By preselecting the next gear while the current gear is engaged, double-clutch transmissions enable smoother and faster gear changes, minimizing the interruption in power delivery.

Synchronized Manual Transmissions

Synchronized transmissions revolutionized the driving experience by providing smoother gear shifts. They employ synchronizer mechanisms that match the speed of the engaging gears, allowing for seamless gear engagement without the need for precise rev-matching by the driver.

Constant-Mesh Transmissions

Constant-mesh transmissions are the most common type of synchronized transmissions in modern vehicles. They use a fixed set of gears that are always engaged with the output shaft. The synchronizer mechanism ensures smooth gear engagement by equalizing the speed of the engaging gears.

Synchromesh Transmissions

Synchromesh transmissions further refined gear shifting by employing cone-shaped synchronizers. These synchronizers provide a gradual engagement of the gear teeth, allowing for smoother and quieter gear changes. Synchromesh transmissions are known for their ease of use and widespread adoption in passenger cars.

Sequential Manual Transmissions

Sequential transmissions are a specialized type of manual transmission that operates differently from traditional manual gearboxes. Instead of the conventional "H-pattern" gear shifter, sequential transmissions utilize a sequential shifting mechanism. This means that the gears are arranged in a linear sequence, typically in a forward or backward direction.

In a sequential transmission, the driver shifts gears by moving the gear lever or paddle shifters in a sequential manner, usually forward to upshift and backward to downshift. Each movement of the lever or paddle results in a precise and sequential change to the next gear. Unlike traditional manual transmissions, there is no need to navigate through an H-pattern gate or use a clutch pedal.

Sequential transmissions are commonly used in high-performance vehicles, particularly in motorsports such as Formula 1, rally racing, and high-performance road cars. Their precise and rapid gear changes offer several advantages in racing scenarios, where split-second shifts can make a significant difference in performance.

One of the key advantages of sequential transmissions is their ability to shift gears quickly and seamlessly. The sequential shifting mechanism eliminates the need for the driver to coordinate clutch engagement, allowing for lightning-fast gear changes. This results in reduced shift times and improved acceleration, critical factors in motorsport competitions.

Automated Manual Transmissions

Automated Manual Transmissions (AMTs) combine the convenience of automatic transmissions with the control of manual transmissions. They are essentially manual transmissions with electronic controls that automate the clutch operation and gear changes.

Single-Clutch Automated Manual Transmission (AMT)

Single-clutch AMTs, also known as Single-Clutch Sequential Manual Transmissions, retain the traditional manual transmission layout but incorporate electronic control for clutch engagement and gear changes. These transmissions offer automated shifting, but the gear changes may still exhibit some delays or jerky motions.

Dual-Clutch Automated Manual Transmission (DCT)

Dual-clutch AMTs, also known as Dual-Clutch Transmissions (DCTs), provide lightning-fast gear changes by utilizing two separate clutches. One clutch handles the odd gears, while the other handles the even gears, allowing for seamless and rapid shifts with no interruption in power delivery. It's worth noting that although DCTs are classified as manual transmissions due to their clutch mechanism, they are predominantly used in automatic mode in modern vehicles. The advanced electronic control systems of DCTs enable automated shifting without the need for manual clutch operation, providing a smooth and effortless driving experience. DCTs are highly favoured in performance-oriented vehicles for their exceptional acceleration and precise gear changes, making them a popular choice among sports car enthusiasts. For example Bugatti installed DCT in their supercars.

Comparisons and Considerations

Each manual transmission type has its advantages and considerations. Non-synchronized transmissions offer simplicity and ruggedness but require skillful shifting. Synchronized transmissions provide smoother gear changes and are more user-friendly. Automated manual transmissions combine convenience and control but may have certain limitations. Continuously variable transmissions offer seamless power delivery but may not appeal to those seeking a traditional gear-shifting experience.

Performance and Efficiency Factors

Manual transmissions contribute to performance and efficiency in different ways. Non-synchronized and synchronized transmissions provide direct control over gear selection, allowing drivers to maximize engine performance. Automated manual transmissions offer convenience without compromising performance. Continuously variable transmissions optimize engine efficiency by continuously adjusting the gear ratio for optimal power delivery.

Driving Experience and Control Considerations

The driving experience and level of control vary among manual transmission types. Non-synchronized transmissions demand precise shifting skills, providing a raw and engaged driving experience. Synchronized transmissions offer smoother gear changes, making them suitable for everyday driving. Automated manual transmissions provide a balance between convenience and control. Continuously variable transmissions prioritize seamless power delivery and fuel efficiency.

Emerging Technologies and Future Trends

Advancements in manual transmission technologies are ongoing. Manufacturers are continually exploring ways to enhance performance, efficiency, and driver engagement. Advanced manual transmission technologies may incorporate improved synchronizer designs, refined automated systems, and innovative gear-shifting mechanisms.

Electrification and Hybridization of Manual Transmissions

As the automotive industry moves toward electrification and hybridization, manual transmissions are also being adapted to work in conjunction with electric powertrains. Hybrid manual transmissions may feature integrated electric motors, allowing for electric-only driving modes and improved overall efficiency.

Potential Impact on Future Manual Transmission Designs

The future of manual transmissions may witness further integration of advanced electronic controls, artificial intelligence, and connectivity features. These enhancements could enhance gear selection algorithms, optimize power delivery based on driving conditions, and provide personalized driving experiences.

Conclusion

Understanding the various manual transmission types empowers drivers to make informed decisions when purchasing a vehicle. By considering factors such as driving style, performance requirements, fuel efficiency, and personal preferences, drivers can choose a transmission type that aligns with their needs and enhances their overall driving experience.

Manual transmissions continue to play a crucial role in the automotive industry, providing drivers with an engaging and connected driving experience. While automatic transmissions have gained popularity, manual transmissions remain a favorite among driving enthusiasts who value the control, precision, and artistry of shifting gears.

In conclusion, exploring the different manual transmission designs allows us to appreciate the engineering ingenuity and advancements that have shaped the driving experience. Whether it's the simplicity of non-synchronized transmissions, the smoothness of synchronized transmissions, the convenience of automated manual transmissions, or the efficiency of continuously variable transmissions, manual transmissions continue to evolve and adapt to meet the needs of modern drivers. By understanding these designs, we can make informed choices and truly enjoy the art of driving.

How to choose a reliable automatic transmission?

Mon, 06 Feb 2023 00:00:00 -0700

Automatic transmissions play a crucial role in the performance and reliability of a vehicle. Whether you're purchasing a new car or considering a transmission replacement, choosing a reliable automatic transmission is essential for a smooth and worry-free driving experience. In this article, we will guide you through the process of selecting a dependable automatic transmission that meets your needs and ensures long-term reliability.

Before delving into the world of automatic transmissions, it's important to assess your driving habits and needs. Consider the following factors:

Assessing your driving habits and needs:

Determine your typical driving conditions, such as city commuting or long highway trips.
Consider your preference for fuel efficiency, performance, or a balance of both.
Evaluate your desired level of comfort and convenience in the vehicle.

Assessing your driving habits and needs: For instance, if you have a daily commute in a congested city, you may prioritize a transmission that offers smooth and efficient operation in stop-and-go traffic. An example of a transmission suitable for this scenario is the Honda CVT, known for its seamless power delivery and fuel efficiency.

On the other hand, if you enjoy spirited driving and prioritize performance, a transmission like the GM Hydra-Matic 6L80, found in some General Motors vehicles, offers quick and responsive gear shifts, enhancing the driving experience.

Determining the vehicle's intended use:

Will you be using the vehicle for daily commuting, family transportation, or off-road adventures?
Are you planning to tow trailers or haul heavy loads? If so, consider the transmission's towing capacity.

Determining the vehicle's intended use: Let's say you're in need of a vehicle for family transportation. In this case, a transmission like the Ford 6F35, commonly found in Ford SUVs and minivans, provides smooth and reliable shifting, ensuring comfort for your passengers during long drives.

Alternatively, if you plan on taking your vehicle for off-road adventures, a transmission with advanced features like the Subaru Lineartronic CVT, equipped in Subaru SUVs, offers excellent low-speed control and optimized power distribution, allowing you to tackle challenging terrains with confidence.

Considering towing and hauling requirements:

Evaluate the weight and size of the loads you intend to tow or haul.
Research the recommended towing and payload capacities for different transmission options.

Considering towing and hauling requirements: If you frequently tow trailers or haul heavy loads, it's important to choose a transmission that can handle the additional stress. For example, the Aisin AW-Series transmission, commonly used in Toyota trucks and SUVs, offers robust torque capacity, making it suitable for towing heavy loads.

Research Transmission Types: Understanding the different types of automatic transmissions available will help you make an informed decision.

Exploring different types of automatic transmissions:

Traditional torque converter automatic transmissions:
- Commonly found in most vehicles, they use a torque converter to transfer power from the engine to the transmission.
- Known for their smooth and comfortable shifting.
Continuously Variable Transmissions (CVT):
- Utilize a belt and pulley system to provide seamless gear ratio adjustments.
- Offer improved fuel efficiency and smoother acceleration.
Dual-Clutch Transmissions (DCT):
- Utilize two separate clutches for lightning-fast gear changes.
- Highly favored in performance-oriented vehicles for their rapid shifts and precise control.

Reliability Factors to Consider: When choosing a reliable automatic transmission, several factors contribute to its overall dependability. Consider the following:

Manufacturer reputation and reliability ratings:

Research the reputation of the vehicle manufacturer and their track record in producing reliable transmissions.
Check reliability ratings and reviews from trusted sources, such as consumer reports and automotive publications.

Serviceability and availability of spare parts:

Ensure that the transmission you choose has a robust network of authorized service centers.
Consider the availability and cost of spare parts for maintenance and repairs.

Longevity and durability of the transmission:

Look for transmissions known for their durability and ability to withstand high mileage.
Consider the materials used in the transmission's construction and the quality of its components.

Reviews and feedback from owners and experts:

Read reviews and seek feedback from owners who have experience with the specific transmission you are considering.
Consult with automotive experts or forums to gather insights and opinions.

When it comes to reliable automatic transmissions, several models have gained a reputation for their durability and performance. While individual experiences may vary, here are some automatic transmissions that are widely considered to be reliable:

Toyota's Aisin AW-Series: Toyota vehicles equipped with Aisin AW transmissions, such as the Aisin AW60, AW55, and AW30-40, are known for their reliability. These transmissions are renowned for their smooth shifting and longevity.
Honda's CVT: Honda has developed Continuously Variable Transmissions (CVTs) that have proven to be reliable in their vehicles. Honda's CVTs are designed to offer efficiency and smooth operation.
Ford's 6F35: The 6F35 transmission, used in various Ford and Lincoln models, has gained a reputation for its reliability. It is known for its durability and ability to handle high torque loads.
Subaru's Lineartronic CVT: Subaru's Lineartronic CVT has been praised for its reliability and performance. It offers smooth and efficient power delivery, making it a popular choice among Subaru owners.
General Motors' Hydra-Matic 6L80: General Motors' Hydra-Matic 6L80 transmission is widely regarded as a robust and reliable option. It is commonly found in GM vehicles and is known for its smooth shifting and durability.

Automatic Transmission	Vehicle Manufacturer	Common Applications
Aisin AW-Series	Toyota	Sedans, SUVs, Trucks, Crossovers (e.g., Toyota Camry, RAV4, Tacoma)
Honda CVT	Honda	Sedans, Hatchbacks, SUVs (e.g., Honda Civic, Accord, CR-V)
Ford 6F35	Ford	Sedans, SUVs, Trucks, Crossovers (e.g., Ford Fusion, Escape, F-150)
Subaru Lineartronic CVT	Subaru	Sedans, Hatchbacks, SUVs, Crossovers (e.g., Subaru Impreza, Forester)
GM Hydra-Matic 6L80	General Motors	Trucks, SUVs, Performance Vehicles (e.g., Chevrolet Silverado, Camaro)

It's important to note that the reliability of an automatic transmission also depends on various factors, including proper maintenance, driving habits, and operating conditions. Regular servicing, following manufacturer recommendations, and ensuring the use of appropriate transmission fluids are key to maintaining the reliability of any automatic transmission. Additionally, it is always recommended to research specific models, read owner reviews, and consult with trusted mechanics or automotive experts for personalized advice based on your vehicle's make and model.

Please note that this table is not an exhaustive list, and reliability can vary based on specific models and years of production. It's always a good idea to conduct thorough research and consult with experts for the most accurate and up-to-date information regarding specific automatic transmissions and their reliability.

How planetary gears work in automatic transmission

Mon, 06 Feb 2023 00:00:00 -0700

Automatic transmissions are complex systems that facilitate efficient power transfer and seamless gear shifting in modern vehicles. Among the key components that make this possible are planetary gears, which operate on intricate mechanical principles. In this comprehensive article, we will delve into the fascinating world of planetary gears, exploring their structural composition, working principles, modes of operation, advantages, common maintenance issues, and potential future advancements in automatic transmissions.

Understanding Planetary Gears

Planetary gears, also known as epicyclic gears, are a type of gear system employed in automatic transmissions. Unlike traditional gear systems, planetary gears consist of multiple gears that work together to achieve a wide range of gear ratios. The fundamental structure of a planetary gear set consists of three primary components: the sun gear, the planet gears, and the ring gear. Each of these elements plays a critical role in the overall functionality of the gear system.

Source: Wikipedia

Working Principles of Planetary Gears

The working principles of planetary gears are based on the interaction and motion of the sun gear, planet gears, and the ring gear. The sun gear serves as the input, transmitting power from the engine, while the ring gear acts as the output, delivering power to the wheels. The planet gears, arranged around the sun gear and meshing with both the sun gear and the ring gear, serve as intermediary gears.

By engaging different combinations of these gears, various gear ratios and speed variations can be achieved. The arrangement of the gears determines whether the output rotates in the same direction as the input (direct drive), in the opposite direction (reverse drive), or at a different speed (gear reduction or overdrive). The torque distribution and power flow within the gear set ensure efficient power transfer from the engine to the wheels, enabling smooth and controlled vehicle operation.

Source: hawkridgesys.com

Modes of Operation in an Automatic Transmission

Automatic transmissions offer a range of operating modes to accommodate different driving scenarios. These modes include park, neutral, reverse, drive, overdrive, low gear, and manual mode. Each mode utilizes specific combinations of gear engagement within the planetary gear set, optimizing performance, fuel efficiency, and driver control.

Source: LearnEngineering (YouTube)

Role of Planetary Gears in Gear Shifts

Gear shifting is a critical aspect of automatic transmissions, and planetary gears play a pivotal role in facilitating smooth and precise gear changes. During upshifts and downshifts, the engagement and disengagement of clutches, along with the synchronization of gear changes, are accomplished through the planetary gear system. This process allows for seamless transitions between gears, ensuring the vehicle operates at its optimal performance level.

Source: LearnEngineering (YouTube)

Advantages of Planetary Gear Systems

Planetary gear systems offer several notable advantages over alternative gear systems. Their compact and lightweight design maximizes space efficiency within the transmission housing, allowing for more compact vehicle designs. Additionally, the arrangement of multiple gears in a planetary set results in efficient power transmission with reduced energy losses, contributing to improved fuel economy. The unique configuration of planetary gears also enables smooth gear shifting, minimizing undesirable vibrations and shocks during gear changes. Moreover, the wide gear ratio range offered by planetary gear systems allows vehicles to operate efficiently across a variety of speed and load conditions.

Common Issues and Maintenance

While planetary gears are engineered to be durable and reliable, certain maintenance issues can arise over time. Common problems include wear and tear of gear teeth, fluid contamination, and malfunctioning clutches or bands. Regular maintenance, such as fluid changes and comprehensive inspections, is crucial to ensure the longevity and optimal performance of the planetary gear system. In cases of significant issues, repair or replacement of faulty components may be necessary.

Future Developments in Automatic Transmissions

The automotive industry continuously evolves, and advancements in transmission technology continue to emerge. One notable development is the rise of Continuously Variable Transmissions (CVTs), which offer infinite gear ratios for enhanced fuel efficiency and smoother acceleration. Additionally, dual-clutch transmissions (DCTs) combine the efficiency of manual transmissions with the convenience of automatic shifting, resulting in improved performance. Moreover, the increasing prevalence of hybrid and electric vehicles is driving innovation in transmission systems, leading to the integration of planetary gears with electric motors and sophisticated control algorithms to optimize efficiency and power delivery.

Conclusion

Planetary gears are intricate and indispensable components within automatic transmissions, enabling efficient power transfer and seamless gear shifting. By understanding their structural composition, working principles, modes of operation, and advantages, we gain insights into the remarkable mechanics behind modern automotive technology. As the automotive industry continues to evolve, further advancements in planetary gear design and transmission systems will undoubtedly emerge, fueling the quest for increased efficiency, performance, and driving comfort.

What Is A Fluid Flywheel And How It Works?

Wed, 01 Feb 2023 00:00:00 -0700

When it comes to automatic transmissions, one component that plays a vital role in ensuring smooth power transfer is the fluid flywheel, also known as a torque converter or fluid coupling. Understanding how this remarkable device operates is crucial for comprehending the inner workings of automatic transmissions. In this article, we will delve into the mechanics of fluid flywheels, exploring their structure, working principles, modes of operation, advantages, applications across different industries, maintenance considerations, and potential future developments.

Basics of a Fluid Flywheel

A fluid flywheel, also known as a fluid coupling, is a type of flywheel that utilizes fluid dynamics to transfer torque from the engine to the transmission. Unlike traditional mechanical flywheels, which rely solely on a mechanical connection, fluid flywheels employ a fluid coupling mechanism, allowing for smoother power delivery and increased flexibility.

Source: mechstuff.com

Structure and Components of a Fluid Flywheel

A typical fluid flywheel consists of three primary components: the impeller, the turbine, and the housing. The impeller is connected to the engine's crankshaft, while the turbine is connected to the input shaft of the transmission. These components are housed within a sealed enclosure. The fluid, usually a special transmission fluid, fills the space within the housing, enabling the torque transfer between the impeller and the turbine.

Source: x-engineer.org

A fluid flywheel and two fans opposite each other may seem similar for torque transmission, but there are distinct differences in functionality and effectiveness.

A fluid flywheel uses fluid dynamics to transfer torque smoothly. It consists of an impeller, a turbine, and a fluid-filled housing. The circulating fluid flow drives the turbine, providing gradual engagement, torque multiplication, and shock absorption. This design enables adaptability to different driving conditions and optimized efficiency.

In contrast, two fans opposite each other rely on air resistance to transmit torque. While one fan drives airflow that rotates the opposite fan, the lack of controlled fluid dynamics leads to inconsistent torque transmission. The fans' design may also limit shock absorption and result in less smooth power delivery.

Source: Lesics Engineers Pvt

Overall, the fluid flywheel outperforms the two fans setup. Its fluid coupling and controlled dynamics ensure efficient torque transfer and smooth operation. It is extensively used in automatic transmissions for passenger cars and commercial vehicles, while the two fans setup has limited applications.

Working Principles of a Fluid Flywheel

Fluid flywheels operate based on the principles of fluid coupling. When the engine is running, the impeller is set in motion, causing the fluid within the housing to circulate. This circulating fluid creates a torque that is transmitted to the turbine, resulting in the rotation of the transmission input shaft. The fluid dynamics within the flywheel enable smooth power transmission and torque multiplication, ensuring efficient power delivery to the transmission.

Modes of Operation in a Fluid Flywheel

A fluid flywheel operates in various modes to accommodate different driving conditions. During idle or when the vehicle is stationary, the fluid flywheel allows the engine to run independently without transmitting significant torque to the transmission, preventing stalling. As the vehicle accelerates, the fluid flywheel engages and gradually transfers torque to the transmission, resulting in smooth power delivery and seamless acceleration.

In cars when the vehicle reaches a certain speed, typically during highway driving, the transmission's computer system engages the torque converter lock-up clutch. This clutch mechanism physically connects the engine's crankshaft to the transmission's input shaft, bypassing the fluid coupling. By doing so, the torque converter lock-up eliminates the slippage that occurs in the fluid coupling, resulting in a direct mechanical connection between the engine and the transmission.

Source: mm4x4.com.au

Source: Thomas Schwenke (YouTube)

The direct mechanical connection achieved through torque converter lock-up improves power transfer efficiency, reduces power loss, and enhances fuel economy. By eliminating the fluid coupling's inherent energy loss and reducing slippage, more of the engine's power is effectively transmitted to the wheels. This improves overall vehicle performance and allows for smoother and more responsive acceleration.

Furthermore, torque converter lock-up also helps in reducing heat buildup within the torque converter itself. Since there is no fluid coupling slippage, friction and heat generation are minimized, contributing to improved transmission longevity and durability.

It is important to note that torque converter lock-up is primarily engaged during cruising speeds, where the engine's power demands are relatively low. During low-speed operations, such as starting from a standstill or during heavy acceleration, the torque converter lock-up may disengage to allow for smoother engagement and torque multiplication.

In summary, torque converter lock-up plays a critical role in enhancing efficiency and reducing power loss during highway driving. By establishing a direct mechanical connection between the engine and the transmission, it optimizes power transfer and improves fuel economy. This feature has become a standard in modern automatic transmissions, contributing to a more efficient and enjoyable driving experience.

Advantages of Fluid Flywheels

Fluid flywheels offer several advantages over traditional mechanical flywheels. Their ability to absorb shock loads and vibrations helps protect the drivetrain components, increasing their longevity. The smooth and gradual power transfer ensures a comfortable driving experience, minimizing jerks and jolts during gear changes. Additionally, fluid flywheels contribute to improved fuel efficiency by reducing energy losses in the drivetrain system.

Applications of Fluid Flywheels

Fluid flywheels find extensive applications in both automotive and industrial settings. In the automotive industry, they are widely used in automatic transmissions of passenger cars, providing smooth and efficient gear shifting. Commercial vehicles also benefit from fluid flywheels, ensuring reliable torque delivery during heavy-duty operations. Outside the automotive sector, fluid flywheels are employed in industrial machinery, such as construction equipment and marine propulsion systems, where smooth power transmission is essential.

Source: x-engineering.org

Maintenance and Common Issues

To maintain the optimal performance of a fluid flywheel, regular maintenance is necessary. This includes periodic fluid checks and replacements to prevent overheating and fluid degradation. In cases of severe issues, repair or replacement of components may be required.

Conclusion

Fluid flywheels are key components in automatic transmissions, enabling smooth power transfer and enhancing the overall driving experience. By comprehending their structure, working principles, advantages, and applications, we gain insights into the mechanics behind their success. As we look ahead, further advancements in fluid flywheel technology hold the potential to revolutionize power transmission systems, driving efficiency, performance, and comfort to new heights in the automotive and industrial sectors.

What Are The Different Types Of Automatic Transmissions

Wed, 01 Feb 2023 00:00:00 -0700

What Are The Different Types Of Automatic Transmissions

This article discusses different types of automatic transmissions available in the market, their advantages and disadvantages, and the shift pattern for each. - The most common type of automatic transmission is the Automatic Torque Converter (ATC), which uses a converter friction clutch and a clutch transmission to control the engine speed. It is similar to a manual transmission but uses a torque converter instead of a clutch. The next type of automatic transmissions are those that use modern automatic transmissions, such as Variable Transmissions (VTs) and Continuously Variable Transmissions (CVTs). VTs allow continuously variable transmission using belts and pulleys, while CVTs use traditional steel gears for coupling and decoupling. The Dual Clutch Transmission (DCT) is another type of automatic transmission that uses two separate clutches for shifting gears instead of one. Lastly, there is the Torque Converter Type Transmission (TCT), which uses both torque converter and clutch to provide smooth shifting.

It is designed to simulate manual gear shifting and is typically used in luxury vehicles. This type of transmission has multiple gear configurations that are controlled by the planetary gearset, which can be operated either manually or automatically. It uses both the clutch system and torque converter to provide smooth shifting between gears, allowing the vehicle to shift automatically without any manual input. The TCT also allows for more efficient use of engine power compared to a conventional manual transmission, as it can reduce fuel consumption by up to 20%. This type of automatic transmission is becoming increasingly popular in modern vehicles due to its efficiency and convenience.

Manual or auto transmission is the choice of many car owners. Manual gearbox requires the driver to manually change gears, while automatic gearbox changes gears automatically as the car accelerates. Automatic transmissions are operated by a computer-controlled system, which automatically changes gear depending on the car’s speed. Fully automatic mode is when all gear changes are done without any input from the driver. In this mode, one gear is used from start to desired top speed. Steering wheel mounted paddles allow drivers to manually change gears in this mode too, if they wish.

Automatic car technologies have developed over the years, and now offer a variety of different auto transmission types. The most advanced automatic cars use a Direct Shift Gearbox (DSG) or Dual Clutch Transmission (DCT). This type of transmission uses two clutches, one for odd numbered gears and the other for even numbered gears. It can use either dry clutches or wet clutches. The dual clutch technology allows for faster gear changes, better engine torque and improved fuel economy than a traditional automatic transmission.

The clutchless manual transmission is a popular choice in automatic cars, as it offers an accurate and free manual transmission without the need of a clutch pedal. The dual-clutch transmission offers a complete clutch operation with lightening fast gear changes, making it match the performance of pure manual transmissions. The vehicle is operated by a gear lever that allows you to change gears quickly and accurately. The latest innovations in the automotive industry have seen the introduction of new dct transmissions that offer cutting edge performance.

Automatic gearbox or ‘transmission’ is a type of transmission that can shift gears without the driver having to press a clutch lever. The automatic gearbox uses either a converter planetary gearset, or torque converter to disengage engines torque and shift gears. A manual gearbox requires the driver to press the clutch lever in order to change gears. A converter automatic transmission is the most common type of automatic transmission found in vehicles today. This uses a torque converter which is connected between the engine and transmission allowing it to change gear ratios as needed. The torque converter also helps reduce engine noise, vibration and harshness levels whilst driving. Another type of automatic transmission is known as a completely automated gearbox. This type of transmission does not require any input from the driver, instead it uses sensors and computerised systems to determine when it should shift gears based on driving conditions such as speed, acceleration and braking force etc.

The most common type of automatic transmission is the hydraulic automatic transmission, which uses a series of planetary epicyclic gearsets to enable smooth gear shifting. Gear selection is usually done using a shift lever or gear lever, which is connected to the transmission control unit (TCU). The TCU then uses automated elements such as sensors and pneumatics actuators to determine when to engage or disengage the clutch. These signals are processed by computer processors and used to control output shafts from the transmission.

The output shaft is connected to a drivetrain that allows power to be delivered from the engine to the wheels. The drivetrain may include a front differential, rear differential, and a differential transfer case. Standard automatic gearboxes use a selector clutch pedal, shifters, and n-d gear selectors to shift gears automatically. An automated manual transmission (AMT) is another type of automatic transmission technology which provides stepped gear ratios without using clutches or complicated software. Dual clutch transmissions (DCT) are similar but provide more efficient shifting performance than standard automatic transmissions by using two separate manual slots for each gear ratio. DCTs are becoming increasingly popular due to their improved shifting performance compared to other types of automatic transmissions. They provide an efficient way of shifting gears while still providing transmission technologies such as AMTs and stepped gear ratios.

Clutch-automated manual (CAM) transmissions are the most common type of automatic transmission, and they work by using a computer to shift gears instead of a traditional clutch. Drive-automatic transmission (DATs) are another type of automatic transmission that uses a dual clutch system to shift gears. This unique transmission type is becoming increasingly popular, as it can provide smoother shifting and quicker acceleration than traditional automatics.

Automate clutch systems are designed to control only the clutch, allowing the vehicle to actuate gear changes without any drivers input. Auto transmissions are becoming more efficient, providing hassle-free rides and better city fuel economy than rowing your own gears. Autostick is another type of automatic transmission that requires drivers input to change gears manually, but still provides full control over the vehicle's performance. For example, some vehicles have this type of transmission to improve lap times or for added escape fun. The most basic form of automatic transmission was used in earlier versions of cars and trucks and essentially used an actuator servo to shift through gears without any input from the driver.

Signs Of Automatic Transmission Problems And How To Detect Automatic Transmission Failure

Wed, 01 Feb 2023 00:00:00 -0700

Signs Of Automatic Transmission Problems And How To Detect Automatic Transmission Failure

However, there are common signs of automatic transmission problems that can be detected before it fails. One of the most common symptoms is when shifting your gears, you may feel a delay or an inability for the gear to properly engage. This can lead to your vehicle not being able to stay in the car's drive or park at times. If you feel an inability for the gears to engage properly, it is best to get your car checked as soon as possible and have it diagnosed by a professional mechanic.

This is because one of the most common signs of automatic transmission problems is when the car refuses to shift gears or changes gears erratically. Another sign to detect automatic transmission failure is if your car starts in one gear and refuses to change even when you accelerate.

This is an absolute refusal to shift gears which could be a sign that your transmission needs service. If you notice any unusual hesitations when you try to accelerate, it could indicate a problem with the transmission. This can also be backed up by trouble codes that are stored in the computer system of your vehicle. Depending on how new your car is, it may have a computer system that can tell you if there's something wrong with your transmission. The best way to diagnose automatic transmission problems is by taking it to a qualified mechanic who can properly diagnose and repair the issue.

However, the incredible early indication of possible transmission issues is to pay close attention to your car's engine light. The engine light will indicate when something is wrong with your vehicle's many different systems, and this includes your transmission. If you notice that your check engine light is on, it may be an early detection signal that your car has some type of transmission issue. Additionally, drivers should be aware of early transmission tremors or jerks that can indicate a problem with the transmission.

If you notice any of these signs, it is important to get your car checked right away. Your check engine light is a key indicator that something could be wrong with your transmission. If the light appears on your dashboard, this usually means that your car needs immediate attention from a mechanic and can save you from serious damage in the future. Similarly, if any of the previous four signs are present in your vehicle, there may be an underlying transmission issue that needs to be addressed.

If you are struggling with your transmission, it may be difficult to shift gears or the transmission may jerk or make other unnatural movements. If you feel a clunk or jerk when shifting gears, this could be an indication of a broken shifter cable. Additionally, low transmission fluid can cause the vehicle to move erratically when put into gear. Lastly, if the valve body is malfunctioning, it can also lead to abnormal shifts and jerks when changing gears. All of these signs are indicative of an automatic transmission failure and require immediate attention in order to prevent further damage to your vehicle.

If you suspect that your shifted automatic transmission is not functioning properly, the first thing to do is to check the transmission fluid level. If it is low, then this might indicate a possible leak and should be checked further. You should also check if the switch brake light switch has been activated as this could cause a blockage in the selector lever module. If there are any visible signs of fluid leaks, these should be checked too as this could indicate worn transmission seals or gaskets. Additionally, it is important to check for any warning lights on your dashboard as this could indicate a potential problem with your car’s automatic transmission system. If you are unsure about what exactly may be wrong with your vehicle’s automatic transmission system, then it may be best to know your mechanic need so that they can diagnose and repair the issue quickly and efficiently. Worn transmissions often take gears from one speed to another slowly or erratically while fluid leaks may cause a sudden decrease in oil pressure which can lead to erratic shifting patterns and takes automatic transmission blocks.

You should be aware of the signs of automatic transmission problems and how to detect automatic transmission failure. One of the most common signs is a depressing clutch pedal while shifting gears. This indicates that torque converter is not engaging properly and requires manual transmission. In manual transmissions, you may notice that it takes longer than usual to change gears or that it gets stuck when you try to shift gears. Another symptom of a potential failure in your engine transmission is an unusually loud noise coming from your engine when you shift gears. This is because the automatic transmissions decouples your engine from the gear sets, allowing it to remain at a constant RPM while shifting gears. If this fails, then the engine RPMs may surge unexpectedly as you try to shift between gears, which can cause a loud noise.

Manual transmission cars use clutch discs to turn power from the engine into power for the wheels. Ford Powershift is a dual clutch transmission that delivers power directly from the engine to the wheels, allowing your car to move quickly and smoothly. It also delivers transmission fluid at the right time and with the right amount of pressure, so that you can shift between gears without any issues. However, if you detect any of these signs of automatic transmission problems, then it may be time to get your car checked out.

Some of the warning signs to look out for include: transmission fluid that has lost its viscosity, oil sludge, improper positioning of shift cable, blocked filters, failed solenoids and connections, faulty sensors and dysfunctional computer system. Furthermore, if there is a mechanical failure in the cable or the incorrect type of fluid used in the transmission system, this can also lead to automatic transmission failure.

Who Invented Automatic Transmissions For Cars?

Wed, 01 Feb 2023 00:00:00 -0700

The invention of the automatic gear change was the result of the combined efforts of several inventors, with notable contributions from Alfred Horner Munro and Adolphus Broomhall. Automatic gearboxes were first introduced in luxury vehicles in 1940, and eventually became available for mass-market cars in 1950. The first experimental hydromechanical transmission was developed in 1904 by the American engineer, Alfred Horner Munro. The transmission used a clutch centrifugal to control gear shifting and was based on a planetary gearbox. This prototype allowed for automatic shifts between two main gears and was operated by centrifugal weights that moved according to engine speed. In the 1930s, soviet engineers began developing new fluid-based transmissions as an alternative to manual transmissions, which were becoming increasingly unreliable due to high levels of mechanical wear and tear. As a result, they invented the world’s first automatic transmission using hydraulic pumps and valves as well as planetary gearsets for their transmission solutions. This groundbreaking invention offered superior performance compared to manual transmissions at the time and went on to become the foundation of today’s modern automatic transmissions.

The first automatic transmission prototype was developed in the early 1900s, soon after the invention of the internal combustion engine. It was a two-speed transmission with a forward speed and reverse gear and no clutch pedal, allowing drivers to change gears without having to manually disengage the clutch. The first fully automatic transmission system was developed in 1939 and used on General Motors’ Hydramatic cars, allowing for smoother acceleration and more efficient use of fuel than manual transmissions. This system had three forward speeds plus reverse, as well as an auxiliary drive that allowed it to be used on early engines that lacked processing capacity.

In 1932, the Canadian steam engineer Alfred Horner Munro was granted a patent for the first automatic transmission. The "Munro Patent" was an improvement on earlier designs that lacked power and efficiency. Munro's invention allowed for smoother gear changes than ever before with compressed air or hydraulic power as its energy source. Munro's design used four forward gears and one reverse gear with a single shift lever, allowing drivers to change gears without using a clutch pedal. The design also featured a two-speed planetary gear system which enabled it to shift smoothly between low speeds and high speeds. As well as this, he added brakes to control slippage between the drive wheels during shifts which further improved reliability and performance of the vehicle transmission system.

Another automatic transmission was created in 1921 by Oldsmobile, a division of General Motors. This new transmission was called the “Oldsmobile Economies” and it offered drivers a choice between two gears: forward or reverse. This new transmission allowed for smooth shifting between gears and the ability to start from a full stop without the need for manually engaging the clutch. Although American cars were the first to feature automatic transmissions, Soviet cars soon followed suit with their own version called the “Volga Model” in 1935. This model featured an automatic three-speed gearbox as well as manual operation, allowing drivers to switch between manual and automatic modes depending on their preference at any given time. The Volga Model proved popular among Soviet drivers and went on to be used in many other soviet-built vehicles over the years.

However, it was General Motors who first created the modern automatic transmission in 1939. This model was called the original Hydra-Matic and became the prototype for all subsequent autoshifters. The Hydra-Matic worked on a four-speed planetary gear set with two clutch packs to shift gears automatically. The first synchro transmission from General Motors was released in 1940 and GM marketed it as the GM Hydramatic, which had commercial success. As technology progressed, a new type of automatic transmission called a mesh gearbox started to emerge in the 1950s and it quickly gained popularity due to its ease of operation. The booming post war economy also meant that more people had access to vehicles with automatic transmissions, leading to their increased usage around the world.

However, who is granted the credits to be the inventor of automatic transmissions? On the one hand invention of the automatic transmission is largely attributed to Alfred Horner Munro. In 1921, he developed a speed preselector transmission which could shift gears without the help of a clutch pedal. This was followed by the development of Reo motor's 1923 “safety transmission”, which shifted into an appropriate gear ratio automatically according to vehicle speed. This laid down the foundations for modern day automatic transmissions. Subsequently, in 1932 General Motors introduced their “preselector” transmissions which used electro-mechanical controls to select an appropriate gear ratio based on engine speeds and road conditions. These models also featured a safety system that prevented drivers from selecting an inappropriate gear ratio for their current speed levels. Today, all modern cars come equipped with automatic transmissions that offer smoother shifting between gears and improved fuel efficiency due to optimized gear ratios and transmission output control systems.

Do Cars With An Automatic Transmission Have A Clutch?

Tue, 01 Feb 2022 00:00:00 -0700

This article discusses the differences between automatic and manual transmissions, and how each operates. A clutch is used in an automatic transmission, but it is operated differently than in a manual transmission. - The clutch pedal is not present in an automatic transmission car as there is no need for the driver to manually disengage the clutch. In a regular manual transmission, the clutch is operated by a pressure foot pedal, and it serves to change gears. In an automatic transmission, the clutch is operated by the transmission control module which is located inside of the automatic transmissions housing. This module manages hydraulic pressure which engages and disengages the clutches inside of the transmission so that it can shift gears.

Depressing the clutch pedal causes hydraulic pressure to be directed to the valve body, which interrupts power flow from the engine and causes pistons in the cylinder to move, thereby engaging or disengaging one gear from another in order for the driver to switch gears. Automatic transmissions use a gear train with valves instead of a clutch in order to disengage the engine from the wheels. The gear train is made up of a number of valves that are opened and closed by solenoids which operate under hydraulic pressure, allowing for smooth and precise shifting. The most advanced type of automatic transmission is known as a dual-clutch transmission (DCT), which uses two clutches that are controlled by electronic sensors.

The first clutch is responsible for engaging the engine with the torque converter, while the second clutch is responsible for providing coupling between the engine and transmission. This system uses a friction clutch to transfer power from the engine to the wheels and to provide coupling when decoupling. Modern automatic transmissions use hydraulic fluid coupling instead of a friction clutch. The hydraulic fluid transfers power from the engine's electronic control unit (ECU) to control how much torque is transferred to each wheel, allowing for smooth and precise gear shifting.

Automatic transmissions are the most common type of transmission found in cars, but manual and dual-clutch transmissions are also available. Automatic transmissions utilize a clutch system to actuate gear changes, but it is not controlled by the driver. Instead, it is controlled by the car's computer. Many car makers prefer to use automatic transmissions because they provide improved fuel economy and reduce driver fatigue. Automatic cars also feature an "autostick" mode, which allows drivers to manually select gears using buttons or paddles on the steering wheel. This mode is used mainly for performance driving or off-road conditions where more control over engine speed and torque is needed. However, many car makers now offer traditional torque converter automatic transmissions, which do not require any driver input to shift between gears. When selecting a car with an automatic transmission, you have several options: traditional torque converter systems; dual-clutch transmissions (DCTs), which use two clutches for faster gear shifts; and continuously variable transmission (CVT) systems that provide infinite ratios for smoother acceleration and better fuel economy than DCTs or torque converters.

But do cars with an automatic transmission have a clutch? The answer is yes, but it operates differently than the clutch found in manual transmissions. Clutch discs are used to engage the transmission gears, while clutches brakes are used to change your gear ratio, similar to planetary gears in a manual transmission. The basic principle of how an automatic gear set works is similar to a manual transmission, as both use clutches and bands that are engaged and disengaged to keep various components in mechanical limbo.

Transmission Solenoids Frequency. What is the right one?

Sun, 09 Jan 2022 00:00:00 -0700

In our last article we talked about frequency and how it relates to the mechanical response of a solenoid when Pulse Width Modulation (PWM) is used to control a solenoid. We discussed some of the theory, but what does this look like with an actual solenoid? How does frequency affect the response of a solenoid and how critical is matching the OEM frequency when driving a solenoid, especially when we start talking about testing and reclaiming solenoids.

To illustrate this, let us take a couple of common solenoids and test them by sweeping from 0 to a max duty cycle, and back to 0 duty cycle over about a 22 second time period. We will do this at a number of different frequencies and compare the output pressure response and see if the frequency a solenoid is pulsed at really has a noticeable effect. We will also determine if this response is different for different solenoids.

For our test we chose a 5R110 PWM EPC Solenoid and a 6R140 PWM Shift Solenoid. The 5R110 is normally open and the 6R140 is normally closed and while their function is similar, they are physically quite different in both design and size. Here are the test specifications for each solenoid:

5R110 EPC Solenoid 6R140 Shift Solenoid

OEM Drive Frequency: 500 Hz OEM Drive Frequency: 1000 Hz

Normally Open Solenoid Normally Closed Solenoid

Test Input Pressure: 150 PSI Test Input Pressure: 150 PSI

Duty Cycle Sweep: 0-45% Duty Cycle Sweep: 0-80%

Test Temperature: 160F Test Temperature: 160F

Figure 1:

Ford 5R110 Solenoid Figure 2: Ford

6R140 Solenoid

Figure 3: 35Hz vs. 500Hz - 5R110

For the 5R110 solenoid we ran tests at 35Hz, 50Hz, 100Hz, 200Hz, 300Hz, and 3000Hz. On the graphs, the solid red line is our expected pressure curve at the OEM frequency of 500Hz. The solid blue line is the expected current curve and the solid gray line is the expected input pressure at 500Hz. The dotted lines are the same readings but at the frequency specified in each caption.

Figure 4: 50Hz vs. 500Hz - 5R110

As we can see from the graphs, we get vastly different results from each different frequency. Keep in mind as we ran these tests everything was set up exactly the same except for the frequency the solenoid was driven at.

Figure 5:

100Hz vs. 500Hz - 5R110

At the low frequencies you could physically hear the solenoid buzz and rattle and you can see on the graphs that the output pressure was fluctuating as the internal valve was moving with the frequency that we were driving it with. We can also see that it was nearly impossible to regulate the output pressure in a stable condition. In fact, it was not until we got to 200Hz, that we were able to get the solenoid to drop to minimum pressure as we rose above 1.0 amp in current.

Figure 6: 200Hz vs. 500Hz

At 200 Hz, our graphs were starting to align with each other. You can still see where the solenoid is buzzing and from the jagged parts on the graph on both the sweep up and sweep down, and the internal valve is still moving somewhat at the frequency we are pulsing it at and causing poor control.

Figure 7: 300Hz

vs. 500Hz - 5R110

Once we get to 300 Hz, our graphs align and literally lie over the top of each other.

Figure 8: 3000Hz vs. 500Hz - 5R110

Now, we do need to be careful as one might think that as long as we are at this minimum frequency or above, things will operate as expected and our testing is valid. One key aspect is that we want the internal valve to float smoothly as we control so we can regulate between minimum and maximum pressure. As part of the experiment, we also tried the solenoid at a much higher frequency, 3000Hz in this case. This caused not only our current and pressure graphs to shift, but also did not allow our solenoid valve to float and smoothly regulate pressure which again gave us a very different response that what was expected.

Figure 9:

50Hz vs. 1000Hz - 6R140

Next, we did the same experiment on the 6R140 Solenoid. Since this one had a higher OEM frequency, we tried this one at 50Hz, 100Hz, 200Hz, 500Hz, 750Hz, and 3000Hz. When we did this, we got similarly interesting results.

Figure 10: 100Hz vs. 1000Hz - 6R140

Again,

at the low frequencies we have extremely poor pressure control and could hear

the solenoid rattle and buzz. In this case since this was a normally closed

solenoid, we were unable to reach the max pressure that the solenoid should

have reached as we approached the maximum duty cycle in our sweep.

Figure 11: 200Hz vs. 1000Hz - 6R140

One interesting thing to note was that even at 500Hz, we still had very poor solenoid control. 500Hz is a very common frequency for quite a few PWM solenoids, especially on four and five speed automatics from a variety of different manufacturers. One might be tempted to conclude that as long as one could test up to 500Hz or so, I should have no trouble testing solenoids. 500Hz is quite a high frequency compared to 35Hz, 50Hz, or even 100Hz. Looking at the graphs for the 6R140 solenoid, its quite evident that 500Hz is not adequate to properly drive this solenoid. 750Hz gets us close to where we our graphs once again lie on top of each other.

Figure 12: 500Hz vs. 1000Hz - 6R140

Interestingly enough, we see the same behavior on this solenoid when we use a frequency that is much higher that the OEM frequency. We see where the solenoid does not float and smoothly regulate pressure as we sweep our duty cycle up and down.

Figure 13: 750Hz vs. 1000Hz - 6R140

As you examine the graphs for both solenoids, it becomes quite clear how important it is to drive a solenoid at the OEM frequency if you are testing and reclaiming solenoids. The ultimate goal of reclaiming solenoids is to verify that the solenoids you have tested and are reusing are in fact good and that you have confidence in your test results.

Figure 14: 3000Hz vs. 1000Hz - 6R140

Over the last few articles, I have talked about the importance of proper testing and how to get accurate and valid results. From these two examples with some real-world data, we can see why these test details are so important. In this case testing at the wrong frequency means that you may be failing solenoids that are in fact good or worse yet, open yourself up to passing solenoids that are in fact faulty. This ultimately defeats our goal of solenoid testing which is to save on the costs of buying new solenoids with each rebuild that comes into our shop.

As you research equipment to test solenoids, it is equally important that you look for a machine that has the ability to drive the solenoids at these proper frequencies. Older equipment like the Answermatic Solx only had 6 frequencies to pick from on its controller. If the solenoid’s OEM frequency was not one of those 6, then you were unable to drive it at the proper frequency.

Figure 15: Hydra-Test HT Sol 25 Solenoid Test Machine

Modern

equipment, such as the Hydra-Test HT Sol 25, gives you the ability to precisely

set the frequency to match what is required for both older and modern solenoids

as you write the specific test scripts. With this kind of flexibility, you are

able to test any solenoid at the proper frequency, including solenoids in new

models being released this year. The added features of the HT Sol are the

increased pressure capacity, superior temperature control, and a large open

work area mean you have a reliable machine that will serve you for years to

come testing and reclaiming solenoids.

Raising own Transmission Repair Company in Germany for over 25 years: Interview with Ulrich Hetzel

Thu, 06 Jan 2022 13:00:00 -0700

Interview with Ulrich Hetzel, Founder / Managing Director
Company / Brand: Hetzel FZTH
Industry: automotive transmission repair and spare parts supply
Headquartered: the commune of Ubstadt-Weiher, Germany
Established: 1993
Number of employees: ~40
Website: fzth.de

_________

Q: How did you arrive to the idea of starting your own company? Was it a tough decision?

Edi (note: Uli's elder brother, co-founder at Hetzel FZTH) was a workshop manager at that-time’s largest rebuilder in Germany, which was more than 28 years ago. He worked there for 5 years, the first half of this company was sold to America and then it was fully sold out to the USA’s Fred Jones Company. Edi brought me in there, while I was a student of business and computer science. I implemented the software system and network on the company, I had an overview and the idea, and Edi had the technical knowledge. They had applied for a big contract but they lost it. That was for OE’s: Chrysler, Subaru, and Toyota. As the contract was lost, the USA heads wrought off the company by firing all people. Edi then decided to open his own company, he asked me if I would join in . I was a student at that time but I agreed. And so we founded the company, it was 1993.

Edi worked there full-time, I worked half a day, my wife – also half a day. Therefore, it was the beginning to start with. I decided to check if everything goes well, and after my diploma, I was going to join fully or continue with business and computer science.

Uli Hetzel

Q: So starting your own company was a forced measure and not own voluntary decision?

Edi had a plan from long before. We had our company before; our father had a car dealership company so Edi had a gene of being self-employed. That was sure to go. The time just fitted well, it was the right impulse. We started as partners, 50:50. And it is the same up to this day.

Q: Why did you decide to base your company in Ubstadt-Weiher?

Our home is not far away. The reason is that my wife lived in Ubstadt-Weiher. I moved there and in the back yard there was a small workshop that was used for building stones in former days. We started off on that room and just after 2,5 years everything was so filled up that we had to move out. We didn’t have any space left, we used even the attic and basement. We had an opportunity to move around the corner, there was a military base there. We could rent it in the beginning and then after a few years we found out that in the neighbor village they were selling a similar building to a private person. So we thought that if they could buy it, we could buy it as well. Therefore, we asked the local government and they were happy, as it could bring in money into the budget. We took a loan and we made this purchase.

Hetzel headquarters in Ubstadt-Weiher (drone view)

Q: What are the major sides of Hetzel business? You do almost all about transmissions. What is the biggest division of the company in terms of production volumes / financial output?

It is a little difficult to say. The variety makes the difference. It is also depending on the market situation, on the competition. We had to find our own profile. There are companies older than us on the market (I mean European market), so that had maybe 20-25 years more in business. They had accumulated profit and experience. It was very difficult to compete with them. Some concentrated on the parts business but didn’t do it. We were doing both: parts business and transmission repair business.

In the beginning, the plan was that we are an interface between the rebuilder and the private customer. Our idea was to be a sales hub but the quality of those products was not sufficient so we had problems all over. Edi had to resolve those problems. The customers at that time told him that it is either him doing transmissions or he won’t be getting any new orders, no work. We came back to what we thought we wouldn’t do: we started to rebuild automatic transmissions of our own, Edi did that. Since then, everything worked well. That was the basis, and today it is still the basis. The Technology, having all knowledge in our own hands, ability to resolve the problems of our own – this is the foundation for our business. We work with OE parts, we work with a lot of technical equipment, we want to produce the highest quality, and this is our major goal. We are in that network of people who rebuild transmissions worldwide, we have good relationships, and we are recognized as a company with everything: solutions to technical problems, supplies, test equipment distribution, etc. We have a lot of experience with that. We had to invest what we earned, into a safe harbor – technology and know-how.

With sales, one day you are making good money and then next day you get a competition who found out how to supply it cheaper – and you are out of the business. We had to think over, how can we invest the money that we earned to avoid the rough sea. What we did is invest in technology, training, know-how, equipment, building – all of that.

Coming back to the initial question, the major business for us is OE business. We have achieved contracts with OE partners – like BMW, ZF, Subaru, and Cadillac Europe. Then Torque Converter rebuilding is important as we do high volumes.

Q: Can you mention any numbers? How many converters per month, maybe?

By year, we do around 5000 converters, and the quantities are growing very much.

We have very important test equipment, we sell and we train. That means, it fits into our plan to represent ourselves as a technical hub. We do not simply sell but we also train other companies how rebuild transmissions, repair torque converters, valve bodies, and so on.

Q: May companies in the world in fact need a company who can both supply quality equipment and train how to work with it, along with the basics of transmission repair operations.

This is something important among what we do; we are open for it. On one hand, people ask us why we do it. Because thus you create competition for yourself. This is not really true for us because it enables us to develop a long time cooperation with them. They may start with filters, oil pans, oil; next step – they will buy some parts and complete transmissions. Then when they start to repair some of the transmissions, they may continue to buy other transmissions from us. When they do all transmissions, we will supply transmission parts.

We feel very open, we like sharing the experience. Sharing can make you richer – this is what we do. For example, Edi said to me 100% of his own business is less than 50% of his business with me, as a partnership.

Q: This is synergy. 1+1 equals 3.

Exactly. We have the same relationship with Alan (Smith, MD at Cottingham Engineering LTD). We help Alan but he helps us as well.

Q: You’ve been on the market for over 25 years, you are in a strong position now. You probably can create allies and not competition, do you?

Very true but it was a long way.

From left to right: Uli Hetzel, Nick Raad (future director of sales and production), Edi Hetzel

Q: As you mentioned Hydra-Test, I’d like to know what other testing equipment you have in your business apart from this brand?

We are also distributors for Hot Flush in Europe, we have made the CE certification for it. It is not officially allowed to use the American version of this equipment in Europe because it doesn’t fulfill European security requirements. We have worked this out. The machine is expensive, really; but it is worth it. Especially for warranty cases. Having this machine for a big rebuilder, it pays off within a year, or even half a year. To be sure that you have no debris and metal pieces coming from the oil cooler back into the transmission and destroying your rebuilt transmission again. That’s very important.

Then we have Tim Eckart flushing machine, it does exclusive oil change. There are other machines, many of them, they all work the same way: you pump oil from one side and you let the engine run, at the other side the old oil comes out. The disadvantage of this method is that while making this oil change, the old oil mixes up with the new oil all the time. And to make the quality of this process reasonable, you need additional 5-7 liters of the fluid. However, when you do it with the machine that we use (which is very simple, by the way), it allows for the idea to drain the complete transmission off the old oil, with the Torque Converter, taking out the filter – you take out all the dirt. At that, you work with a cleaner. Remaining 0.5-1 l of old oil is then slushed out with the new oil. Possibility of mixing old and new oil is eliminated. You simply need extra 0.5-1 liter of new oil, so you save quite a lot of fluid. This Eckart machine is a German product.

Then we also work, still, with Kinergo, PowerTest that bought Superflow. Recently we’ve sold a PowerTest dyno. Then we represent Autel, similar to Launch diagnostic tools. Then also tools to reprogram ECU’s, for cloning and reprogramming. It is called Magic Motorsports, Italy.

Q: What are your key markets except for the German? What is your geography?

This is changing all the time. For many years we had a lot of overseas business relations. For example, we sold very big quantities to the USA. This went down over the years. Today, definitely, the German market is the biggest market for us. Also because of the OE’s we work for, but we have several countries where we are pretty strong – for example, Italy, Romania, France, also Asia, China, New Zealand. The Asian market requires OE – pretty curious thing: on one hand, they sell quite a lot of products to abroad and to overseas but, on the other, the Chinese of their own insist on OE products. They are willing to pay more to have OE quality. As we have quite a few important factories in Germany and Europe, we buy direct from them: molded pistons, solenoids, frictions and steels – then also OE parts from dealership at discounted prices… This is quite an interesting business. We sell really worldwide.

Summing it up, roughly 50% of what we do goes to the German market and the other 50% to other European countries and further. Importantly, the longer the distances are – the bigger the quantities. Abroad, we have big dealership that buy a complete box, pallets with parts. In Germany or Europe it is minor orders day to day. We also do business for rebuilders – when a part is ordered today and they receive it tomorrow, so called ‘next-day operations’.

Q: How do you estimate the European market for the ability to invest in dyno test stands, which are quite expensive? This revolves around 80,000 EUR. What is the market capacity for this type of equipment?

We are open to buying a dyno, but we need help and support. What needs to be understood, is that certification is a must. It protects the people who buy the machinery. If you are producer or importer, especially if importing from long distance – for example, USA – you bear full responsibility for the supplied product. Because if it is from the USA, that USA party cannot be held responsible. As an importer, you have to do risk evaluations; you work out all the possible dangers and minimize them to avoid harm to operators.

Indoor seminar at Hetzel FZTH

Q: Do you think this certification is truly required or it is more of a restriction?

In my opinion, it is absolutely necessary, it is just OK, not overestimated. It puts responsibility to the ones who make money with it. If you want to earn profit, bear responsibility. And, there is nobody really who controls you. A control happens when an accident happens. People will check if you have fulfilled all requirements. They will analyze the causes of the accident. If they find out, you didn’t your job well, then they take you for responsible. If they find out, you did all that was needed, the reason may be declared for unforeseeable circumstances. It is difficult to understand this system because it is a self-control system. And you have to write it officially, that when you do import, you have done everything that was needed to prevent harm.

Q: Understood. Actually, the initial question was: what is the capacity of the European market to afford buying a transmission dyno? What is the demand for transmission dynos in Europe?

Very small. This is a niche in the niche market. Automatic transmissions for me are still some kind of a niche. It grows, yes. It will continue to grow, yes, but it was a niche market, not a virgin market any longer, but it is not a big market. Therefore, we have worldwide networking because you don’t find partners and knowledge in the neighborhood. You need to have certain volume and payoff to make it effective. The necessity is there if you do an OE business: you rebuild for a car manufacturer, for an importer. Then they require it from you that you test what you rebuild. There aren’t so many companies that need it: 70% of the companies are 1-man band, 20% - 2,3,4,5 people, and just a handful - more than 10 people working with automatic transmissions only. The market is very narrow.

Q: You include CVT’s and DSG’s in the same field, correct?

Exactly. Everything that is automatic. There is one exception for us, which is automated transmissions. There are 2 reasons for this exclusion: first thing is if there is enough value to compete with the OE’s. If you drive a manual transmission, you can buy it for 1,000-1,500 EUR from the dealers. There is not enough value to compete. However, if a transmission costs 5,000-10,000 EUR and you can offer it for half of the price, then there’s a huge buffer in between. For example, all the CVT’s, they’re the same volume as normal automatic transmissions and DSG’s. The automated manuals, on the other hand, are of lesser value and lesser comfort. Therefore, we do not touch them. They are more economical, however, because of the technology. Nevertheless, the technology here is not the problem.

Chef mechanic Kim

Q: What do you think of the electrification trend happening now in the automotive industry? How soon will electric cars take over the market? Aren't you afraid that this trend will put you o ut of work?

There are many different feelings about this. Personally, I was pretty much afraid of the Diesel scandal. People were unsure if they could have a diesel car, if they will be able to drive it in cities. There was much uncertainty around it at that time. Edi was sure that it would take longer to change. We’ve done our homework, however. We’ve spoken to car manufacturers, to suppliers like BorgWarner, ZF. All said it wouldn’t come so quick. Otherwise, it would have been a disaster.

There are so many problems with electrification development. No infrastructure, no stations to charge the batteries. And charging takes too long. Also, many cars don’t match the charger, many vehicles have to be towed. Maximum you can drive is 200-300-400 kms. If you turn on the heater, radio, air conditioner – it may come a half of this distance. It is not an equal alternative to combustion engine. The hybrid technology is a different thing though – it is a working technology with fewer issues rather than 100% electrification. The hybrid technology is nothing to be afraid of in terms of rebuilding. You have to rebuild them the same way as the automatic boxes.

We see that car manufacturers try to polish their ecological image by taking about the hybrids the same way as about the 100% electric vehicles. We see now that the hybrids are getting a bigger share of the newly sold cars, while the CE cars are getting fewer, and the electric cars are 1,5-2% of the total. Therefore, there is a big increase in percentage but in real numbers 100% electric cars are slow. Nobody wants to take all those problems. This is summing on our evaluation of the electric vehicles’ market.

With the hybrids, you need to know how to work with high voltage. Not many people know how hazardous it is, touching hybrid electrical system may cause death. We have started very early with hybrid transmission because we have a contract. We rebuild them for an OE company. We have been having this contract for over 5 years. We are prepared for the future.

Hybrid Transmission

Q: How do you establish good and lasting relations with prominent car manufacturers?

For many years, Edi was saying that we needed to have the right stand. For a long time we were not prepared to invite OE companies. If they had come to our former building, they wouldn’t see all that we do, the quality that we produce. You have to give it the right outfit to put forward your quality. There are many rebuilders outside that produce very good quality and you can rely on them. However, nobody really knows them because they don’t have the right approach to the market. 8 years ago, we opened our new building where everything is well-organized. This is the approach now, when people see our company they understand that we do the right job. The OE’s recognized this. It fits altogether now.

We know people in the market. We have many friends and partners and we see them again and again. For example, we have a partner in France: Jean-Claude who had worked for the GM factory in Strasbourg for over 38 year. He was the right hand of the factory boss there. He settled the connection for us and was a bridge for connection with BMW. When people recognize your work with OE’s, they want to do more with you. We also have ZF as our customer. This happened around the same time. We work close with them, we’ve known people from ZF for decades, we met in the USA, at transmission expos. Finally, at some point they said: “Hetzel can work with us”. It is like building a house, you start with the foundation, a solid concrete. It also takes time and strong relationships. We’ve worked hard on this. We also support the international networking and we stand by the same values as 10 years ago, we are consistent and do not let people down.

Transmission solenoids: PWM, Frequency, Duty Cycle?

Sun, 02 Jan 2022 00:00:00 -0700

In the last couple of articles, we used terminology relating to pressure control solenoids such as PWM, Frequency, and Duty Cycle. In this article I thought I would go into depth on what these terms really mean and how they relate to solenoid control. As transmissions have gone from only a few pressure control solenoids to many or even having all of them as pressure control solenoids, a good understanding of these terms is critical for diagnosing error codes and testing solenoids and components when vehicles come into your shop.

PWM stand for Pulse Width Modulation. A quick google search yields a definition on Wikipedia. They define PWM as “a method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts. The average value of voltage (and current) fed to the load is controlled by turning the switch between supply and load on and off at a fast rate. The longer the switch is on compared to the off periods, the higher the total power supplied to the load.”¹

Let us break this down into what this means, especially in terms of solenoid control. Pressure control solenoids are current controlled devices, meaning that the output pressure is a function of the current draw of the solenoid. In a properly functioning solenoid, the same current will give us the same output pressure each time we apply it. The easiest way to change current on a solenoid is to vary the voltage applied to it. For example, if we apply 6 volts to the solenoid and it draws 0.8 amps, reducing it to 3 volts would reduce the current to 0.4 amps. By varying the voltage we apply to the solenoid, we are able to vary and control the current between 0 and the maximum amount of current needed to fully operate the solenoid (usually 1.2 to 1.5 Amps). Therefore, we are able to vary the pressure out of the solenoid between 0 and the maximum pressure that the solenoid can output.

Pulse Width Modulation is a method that allows us to do this. We switch (or pulse) a solenoid on and off very quickly (multiple times per second) between zero volts and ignition voltage. The amount of time it is at ignition voltage vs. off is the duty cycle. If it is on for 50% of the time and off for 50% of the time, this is a PWM signal at 50% duty cycle. If ignition voltage is 12V, we are effectively powering the solenoid at 50% of this, or 6 Volts. If we reduce the on time to 25% and the off time to 75%, we now have a PWM signal at 25% duty cycle and the solenoid is now effectively being powered at 3 volts. As we vary this amount of on time vs off time, we are modulating the pulse width, hence this is where the term Pulse Width Modulation comes from. See Figure 1 for an illustration of PWM signals at different duty cycles as described above.

Figure 1: PWM and Duty Cycle Diagram

Frequency as it relates to PWM, is the number of times per second that we repeat the on and off cycle. If we pulse the solenoid on and off at a given duty cycle 30 times a second, we have a frequency of 30 Hz. If you look through any GM literature on early GM four speed transmissions, they clearly state the EPC solenoid had a frequency of 292.5Hz. This means that the EPC is pulsed 292.5 times per second. This was later changed to 585 Hz. Early Ford EPC solenoids were around 600 Hz. Many early lockup solenoids were in the 30-35 Hz range. Later model vehicles that have multiple pressure control solenoids tend to use higher frequencies on the pressure control solenoids. Pulsing them at 1000 to 2500 Hz is now very common.

Figure 2: Frequency Diagram

You might ask the question: Why bother with PWM at all and not just vary the DC voltage to a solenoid like a benchtop power supply where I turn the knob to vary the output voltage? Wouldn’t this be a much simpler way to control the solenoid? When it comes to electronics (especially in the case of a TCU) a variable DC supply such as one controlled by a microprocessor ends up being a somewhat complicated and expensive method for solenoid control. By comparison, even the most inexpensive and basic microprocessors have PWM capability built in and the actual programming code to accomplish it is also very simple. Hence even from the early days of pressure control solenoids, using PWM as a method of voltage control became the preferred way to control solenoids because for TCU hardware and software designers, it was very easy and inexpensive to implement.

A second question you might ask: Why are there so many different frequencies to control solenoids with PWM then? Why does everyone seem to use a different frequency? There are two reason for this. The first relates to the internal circuitry of the TCU. The internal parts used determine a number of different frequencies easily available from the microprocessor in the TCU. The processor might have a base PWM frequency of 4000 Hz. With simple math internal to the processor, you can easily divide this by 4 and get 1000 Hz, or 8 and get 500 Hz. Since each auto manufacturer is going to use different electronics and different microprocessors, the exact frequencies available will vary from manufacture to manufacturer.

The second and probably more important reason for a particular frequency is that as a general rule, the electrical frequency should be at least 10 times the mechanical frequency of the solenoid. What this means is that a solenoid can only physically respond so fast to abrupt changes in current. Let’s say we started pulsing the solenoid at 1 Hz and then slowly increased the frequency until we reached 30 Hz and found that is as fast as it can physically respond to this electrical signal. Above 30 times a second it cannot actually move fast enough to keep up with the pulsing. 30Hz is the mechanical frequency of the solenoid. When we are controlling with a PWM signal, we want a smooth control so that the solenoid more or less gets an average current rather than pulses. This allows the internal valve to “float” and it moves smoothly as we increase or decrease the duty cycle so that the pressure holds steady and smoothly increases or decreases. For this solenoid, the PWM frequency should be at least 10x this mechanical frequency, or in this case 300 Hz.

Now that we have covered the terminology and how PWM works, you can see this for yourself on vehicles in your shop. Many of the good automotive graphing scopes used for looking at sensors and waveforms do a very good job of displaying these PWM waveforms. Many will automatically give you both frequency and duty cycle measurements. Try back probing a vehicle harness on the two wires to a pressure control solenoid at the transmission connector. Start the vehicle and let it idle and observe what you see on the scope. You should see a PWM waveform like in Figure 3 and 4. Since this is a 4L60E, upon initial start up the line pressure was higher as seen in Figure 3. Once the vehicle warmed up a bit, the line pressure dropped and the typical idle and as you shifted from P-R-N-D can be seen in Figure 4. As you can see, as the duty cycle changes, this means the solenoid current changes, and therefore the line pressure is being modulated inside the transmission. If this were a later model clutch to clutch unit, we would be modulating the apply pressure to the particular clutch the solenoid controls.

As you observe these waveforms on your scope, I hope that this helps bridge the gap between what PWM control is and what is physically happening inside the transmission. This understanding should also help you with your diagnosis process when vehicles come into your shop.

This should also give you a better understanding of what to look for when it comes to test equipment for testing solenoids and valve bodies. In order to give the most comprehensive tests, you should look for equipment that controls solenoids in the same way as the OEM’s do, by PWM. You should also make sure you have the ability to quickly and easily change both the Frequency and Duty Cycle of the solenoids at any point of the test sequence. Both the Hydra-Test HT Sol and VBT Deluxe use the same advanced controller which has the features described built in as standard and our control software allows you to easily change these parameters in the test sequence or add extra steps for more in depth testing and diagnosis. This gives you control of your testing and the ability to change or modify any test at any time.

References:

1. Wikipedia contributors, "Pulse-width modulation," Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=Pulse-width_modulation&oldid=973206164 (accessed September 10, 2020).

Interview with Raybestos Powertrain production development team

Fri, 31 Dec 2021 13:00:00 -0700

nterview with Joe Villain, Director of new product development, Irvin Gers, Sales and production development support engineer, and

Company / Brand: Raybestos Powertrain

Industry: automatic transmission parts manufacturing

Headquartered: the state of Indiana, USA

Established: 1902

Number of employees: ~500

Website: raybestospowertain.com

Go4trans: Please tell us a little more about your roles at Raybestos Powertrain.

Irv: When I was hired in, they were looking for somebody that had tech expertise in product itself and could communicate the engineering jargon to the sales team. I am helping the sales team better understand the products and do job their job better.

Joe: as we develop a new product, we also have to communicate with our distributors and their sales team and they actually need to understand the new product that we are introducing. More or less, on a monthly basis, we visit our distributors, we present a new development, and we educate them. Most of our major distributors.

Go4trans: Is it done in a personal meeting or digitally?

J: At this day, in the wake of COVID-19 personal meeting have been hindered. If not for COVID Irv and I would go to the actual distributors accompanied by our sales guys and present it within 20-30 minutes. Doing this in person is more effective as you talk to people, you see them face to face, and you explain how a solution (a physical asset small enough to take with us) is implanted into the product, into the clutch pack.

Go4trans: Does this involve a lot of travelling around the country?

J: Up to ¼ of our time. Many of our major distributors are close-by – in Kentucky, for instance – so we can go down and be back in a day. At this, we are quickly back in to the development center where we do development on a daily basis.

Go4trans: How big is Raybestos Powertrain distributor group?

Nick: We have roughly 300 aftermarket distributors globally.

J. I graduated with an engineering degree. Started at Hershey, and then went on to Sony. I was accustomed to working at a facility that had a full supply chain distribution. Raybestos Powertrain works the other way: we work with many-many distributors throughout the nation.

Go4trans: You must be have built some strong ties with US vehicle companies like GM, Ford, Chrysler.

J: Indeed, Nick, Irv, and I are on the aftermarket side; however, Raybestos Powertrain has an OE side, which interacts with many Original Equipment Manufacturers as well.

I: We also do heavy-duty and motorcycle products. We have quite a list of heavy-duty products, although my work is primarily based within the automotive aftermarket.

Go4trans: What is the product that you personally are particularly proud of?

J: That’s what me and Irv are here for (laughs). From my perspective, there is a lot of products to be proud of. But I think more than anything, I am proud of the innovation that the Raybestos Powertrain NPI (New Part Introductions) team is giving the marketplace. When I first started here as an engineer, we always pushed to be ahead of the curve, as far as new product introductory. For instance, OE releases a new product to the marketplace – in a particular year, make, and model. What we do, we have datasets that provide us registered vehicles in the United States and that we have forecast data that we purchase that shows the projected units over the next 5-8 years. At this, Irv and I and the NPI board review this data and analyze what is the best opportunity for us in terms of demand and volume. We are also after the market percentage rate: if it is high, we are likely to get a serious market share if go after this particular transmission.

I am particularly proud of this year, from 2018 to 2020 we have introduced a number of new designs. A lot of new OE transmissions have been released and we come out with a re-design in the same year. The value of that is that (for aftermarket), if an OE releases this in 2020 we release a performance application the same year. Some people even ask us: why do you do this, the OE is even not out of warranty? We have a lot of friction materials in our Stage-1 red materials, GPZ materials, Gen2 blue materials that are specifically for performance applications. Nick does a great job in terms of marketing perspectives: we have a lot of online presence.

N: We also pay attention to transmission rebuilders discussion boards and forums. Transmission Brotherhood is a well-known group on Facebook.

J: I we need to get feedback from these guys that everything goes well for them. Performance applications – like Corvette, Mustang, Camaros.

I: …diesel trucks…

J: Clever point. In the USA diesels are a big thing. Many of these guys with a Corvette, Mustang, Camaro, and diesel trucks are willing to void their warranties and drop that transmission to have us redesign clutch packs for them. They soup-up or modify the engines to provide extra performance – more horse power or more torque. We get feedback from Nick saying this is a possible scenario that we need the best solution for. We additional checks with our distributors, with ourselves. We then need to look into the forecast data and it’ll say ‘X’ of this product will be coming out (say, a million). Irv and I will buy a transmission to do the redesign on. Oftentimes, guys will drop a transmission and send it to you so that you can do design work on that.

We at Raybestos Powertrain have a design room – we call it a ‘war room’. NPI will start working on a new transmission pulling it apart so we can see what physical assets are within this clutch pack. We see what are the physical dimensions of that friction plate, or that reaction plate, or the pressure plates, or the applied plates, snap rings, pistons – what we can do to modify and improve within this clutch application to give us a new product. I am most proud of the technology that we provide to the marketplace the same year that OE releases. We’re setting records, in fact.

I: Corvettes with our transmission parts are winning races.

J: The prototype design work that the NPI has just completed on the C8 Corvette. Our prototype clutch pack is in there. And it is the first C8 Corvette, the first TR9080 transmission in that year, make, and model Corvette 2020 to go 9 seconds.

I: A record was just broken with a 1500 h.p. 10R80 Mustang that used our GPZ plates.

J: In 2018 we worked hard on developing product for the 10R80’s, the 10L80’s and the 10L90’s – this is raging in the USA and will be in the rest of the world. Again, the OE designs them for the general market so they are looking to provide a good product at the lowest cost they can do. They are not looking for a performance friction material to bring the engine well over 1000 horsepower – and this is where we step in along with Dan Truncone, who is also a part of the NPI team.

That Corvette, I am proud that we could see the data, identify the performance aspect, develop a new product and break the track record. We did the same with a Mustang 500s running with 10R80 and it has our clutch pack in it. We set the record on Saturday and we are coming in on Monday to sell this product all day long.

We have our performance material applications; we also have got OE replacement materials that will be more economical for those guys looking for warranty replacements. Hopefully, we have established ourselves as the dominant provider of the 10R80’s, for example in the performance world, before they are even out of warranty. Therefore, as the transmission rebuild community has those conversations, they know Raybestos Powertrain will cover performance products, and then 3-5 years later we can also be there for OE replacements with more economic materials.

As we look at material upgrades, we also look to dive in and see if we can add more material capacity. Irv will step in here.

I: One of the things that has been presented to me when we were working on upgrading clutches for the performance market, is that we don’t always need to just put in different friction materials. If a person has a failed clutch, we try to get our hands on that clutch. Then our team in the tech center develops new materials and tests them. We have SAE dynos here and the team tests new materials not just for performance or durability but they will also test them for failure to recognize the failure mechanism. They can help us determine: is just adding more clutch plates in there going to be the answer or do we need to do something else with the way this clutch pack is designed? Sometimes, it is about having more clutch area and maybe I can change the ID of the wafer or the OD of the wafer in order to get more surface area in there. I also get the opportunity to work with, maybe changing the grooving design to see if we can get more cooling or oil flow there.

People think that adding another clutch plate will do the job of improving but there is a lot of science in there. Part of my job is, once a failure is identified, to answer what we can do to improve and minimize the failure. We also are concerned about the right clearance and once we go through all engineering, they send me the prototype samples, and I fit test them. Thus, I find out if the thickness is correct, or we need to rethink some aspect. We identify if the prototype process has seriously changed something. This is how cover the demands of the performance market.

J: You mentioned dynos but we also have simulators run by our Doctor-level engineers. It is a combination of theory and diagnostics.

I: When developing for an OE supplier, we have FEA (failure element analysis): you dump a bunch of data into this program and you run a simulation with the computer. The returned data shows how this material responds, what the potential failures are. Then you can tweak the program and rerun it to see if you’ve made the right improvements. They do a lot of this before we start making prototypes and dyno testing them. So, this is the process: run the simulation, see how you can tweak this thing to make it the best that you can, then you make prototypes and dyno-test. At that, you see if the dyno test shows the same results as the initial program. After that, we do field testing: we make more prototypes and we get it out in the field to get real-time testing. Thus, we see if we did it all correctly or if we need to get back to the drawing board. In the end, it is obvious that hard labor is required to produce the top result.

Go4trans: This seems quite special about what you do in the parts supply section. Is such attitude to the R&D your special feature?

I: As far as I know, we are the only company that manufactures frictions clutch plates, steel clutch plates, and similar products, that is vertically integrated. In other words, not only can we test new designs, we also develop our own resins, and we can design and make our paper.

N: One of the unique things that we have here is our paper mill.

I: Yes, we make our own paper. We develop new formulas for the paper and for the resigns that we saturate our papers with. We, basically, cover everything from the ground up. This really helps when we’re in the middle of testing and tweaking this and that, we don’t have to rely upon anyone else.

J: Correct, and remind us how many years you’ve been with Raybestos for? What did you do before?

I: 16 years it is and prior to Raybestos I spent 17 years rebuilding transmissions, I worked on the help line for ATRA where I actually did diagnostic work over the phone. We also wrote bulletins and seminar programs. If I happen to have a transmission, on my research hours I would check if we can find fixes for a certain transmission. Then I went to work for a remanufacturing plant and a distribution place and worked as a Technical Director there. I have been in the industry for a few years (laughs).

J: I wanted Irvin to say this because he’s been in the transmission world for a very long time. I am an electrical engineer that worked for Hershey and Sony where everything was automated, and when I came here 5 years ago here’s what impressed me: we have a whole facility here not just the aftermarket product but also OE products. Not only do we have a fully-functioning paper mill where we can do mass volume, we also have a paper mill within the tech center that our Doctor-level engineers can use in full – changing recipes daily if they need to, running small runs and testing these materials on our dynos. We also have lasers used to cut cores. All this covers the prototyping and this is vertically-integrated. Summing it all up, we are a self-contained tech center backed up by top engineers. This is our distinguishing factor that even puts us ahead or level with OE’s.

Go4trans: At this, what kind of management structure do you have at Raybestos Powertrain? Do you feel it family-like or rather hierarchical?

I: Lorenzo is our CEO and when he came to our company one of things he did is he grabbed the NPI group at that time and he basically asked us questions like: go around the table and tell us a history about what you are about, what do you do? Sometimes that is a little unnerving because you never know why you are asked these questions – maybe he is considering firing you? But I actually give him a lot of respect for that because he was interested in the people here. I also found out he likes the same football team I do which was a little bit of camaraderie there. We would sometimes discuss our team and talk about the bad point and good points. I would say it is more family-like situation but it’s sure also business, when he needs to deal with the business side.

J: It is very much about the relationship here. Lorenzo may not be here all of the time but he’ll come in the war room on certain days, he’s very interested in what we’re working on. We feel comfortable with the CEO coming into the room, talking to us. In many organizations – like Sony where I had spent 21 years – you don’t talk to the CEO. Throughout those years at Sony, maybe I spoke to the CEO a couple of times. You know, we work jointly with the Director of sales too, and we travel together. From our perspective, as the NPI team, there’s a great family relationship here. I believe, there’s always up and downs within every company, it isn’t necessarily perfect, but a good relationship is very important. The Truncone family have been here for generations for example. How many is it, Nick?

N: I am actually a 4^th generation employee in my family. My great-grandfather started working at Raybestos in Connecticut in the 1940s. My grandfather was an engineer and retired in 2006. He designed several friction materials that we have used over the years and are still using today. He was transferred to the Crawfordsville, Indiana location in the 1980s. My dad began working for Raybestos in the 1980s and I started in 2012.

I: Could you briefly tell us about the testing equipment used in your R&D dept? Dyno, some TC testing equipment, etc.?

J: We have a lot of assets, like MicroView, for instance. It is hugely valuable. When I first came here, we would do all the dimensional checks. But what was needed is a ‘go-no go’ gauge. When we set a program on a laser cutter we have to do some quality checks during a production run. What they would do is use the physical clutch hub of that transmission to drop that part into to say ‘yes, it fits, to verify that the specific product dimensions weren’t going astray’.

MicroView is a so-called ‘Virtual Hub’, it allows Irv and the development team to scan the brand new part and feed the program. This allows for a substitution to a physical part. It is extremely useful on the manufacturing side.

Irv can share more on this.

I: We are always trying to improve. That MicroView is a vision system and it is also a CMM (coordinate-measuring machine) all wrapped up in one. That allows me to get dimensionals on a part and, depending on the difficulty, I use different methods: optical methods or a touch probe when necessary. As for friction plates for instance, I can cast a shadow from underneath the part and I can get all the dimensions of the shapes of the teeth, the outside and inside diameters, depending on how many splines there are. I can get all that with a vision system but actually going in and getting the information I need on the thickness of the wafer and the shape of the grooves and all that. Sometimes I have to use a combination. You can’t cast a shadow through the steel core. Therefore, you have to be able to look down on it, or reach down and touch it in order to get the measurements. That data is now captured in that program and I can place that part on a particular grid pattern and record. Later down the road when we do checks instead of re-measuring (instead of what Joe was explaining) – especially if they can’t find a hub – they can take this thing over to the vision system, put it down on there the same way as it was oriented when we first did the measurement. It will run a test probably anywhere from 20 to 30 seconds, it can measure that part and we compare it to what was in there previously and then it can tell me if it matches or not. We can run 3-4-5 samplings trough there – as many as we need, and this quickly tells if we’re on the right track or not.

I can take that measurement into a CAD (Computer-aided design) program and then I can use that data to start with. If I want to tweak something in there or change the design from the OE, I can do that with my CAD program. That is also useful and I can do prints from there. It was like a child’s Christmas gift for me.

Go4trans: And do you also use transmission dyno test stands?

I: Our dynos are SAE #2 dynos. Our engineering team would tell more about them and the controllers. I don’t run them.

N: Check out this info - https://www.raybestospowertrain.com/oem/dynos.

Go4trans: As you are in the R&D dept, can you shed some light on your strategic plan for the upcoming years?

J: From the NPI Director’s perspective, it is driven from the bottom up, we try to be ahead of the curve, strategically. We use our data sets for registered vehicles – domestically and internationally – and we check forecasted units, so that we can forecast which units will be strategically important, how those developed, and hopefully the same year as the OE releases we can design and improve on those materials. The vision is always to be ahead of the curve. We release performance solutions so that we can enjoy that upfront revenue associated to those improvements. This year we have already developed the list of transmissions that we’re after. We’re already looking forward to 2021. We also are very much interested in developing new extra capacity GPZ Torqkits for upcoming transmissions.

We are already striving to determine what will be most important in 2021. We look into the forecast data, we talk to distributors and transmission rebuilders through social media, and we track our enquiry database. Sometimes development takes up to 6 months, and Raybestos Powertrain aspires not to react but to have the product ready when it is needed.

Interview with Normunds Aspers, Commercial Director at RECRO

Mon, 27 Dec 2021 13:00:00 -0700

Interview with Normunds Aspers, Commercial director

Company / Brand: Recro

Industry: automatic transmission remanufacturing

Headquartered: Latvia

Established: 2008

Number of employees: ~45

Website: recro.eu

Interview with Normunds Aspers, Commercial Director at RECRO

Q: How long have you been with RECRO for? How did you join the team?

I am with a Recro since September 2013. It seems, this month I have 7 years’ anniversary. We have been good friends with Recro owner Raimonds for a long time and I had been helping him with all kind commercial matters for many years. After the idea of developing the automatic transmission remanufacturing facility in Cesis was born, I had an invitation to join the Recro company.

Q: What are the major sides of RECRO business? What is the top division of the company?

80% of our net sales comes from full transmission remanufacturing. The rest is parts and component sales. 90% form all transmissions we reman today are for passenger cars however, we see continuous increase of industrial and commercial transport transmission share and this demand will keep growing, I am sure.

Q: How long has the company been on the market?

Recro was established in 2008 but our key persons are in business since 90s.

Q: What advice would you give to those who are currently trying to enter this business field? Where to start? What should be avoided?

Well, this is not a quick business (in many aspects) and you should be ready for long journey.

Q: What is your major instrument in driving your business forward?

It is hard to say what is the major instrument. We have many, and all of them are important. In terms of marketing, the Google tools today bring many opportunities and help to understand the market better.

Q: You have around 10 language versions of your website. Is this really beneficial to have so many language versions? In addition, do you have sales managers speaking all of these languages?

Not 10, just 8. Well we are not unique in this respect. It is for sure much easier to approach local market in local language. Yes, we have sales managers covering nearly all languages we have at our web site. I do not mean that it is one person who speaks all these languages. We have local representatives in our main export countries.

Q: You probably had some obstacles during your company’s growth. What was the biggest one or maybe you still have some?

We face daily obstacles, just as any kind of business does. In our industry, great challenge is lack of technical information that often you gain only from your own experience. OEM’s are trying to keep the data in secret as much as possible.

Q: What is your target market now?

Basically, all EU countries are in our target range.

Q: Does membership of Latvia in the EU give you many benefits in business?

The answer is very straight. We would not be able to work in the EU without being an EU member state.

Q: Do you have branches or offices outside Latvia? If not, why? If yes, what objectives do they cover?

No, we don’t. We have only sales representatives so far. However, we have some plans to open service centers outside Latvia too.

Q: You have a Hydra-Test machine in your business. Do you use it daily in your operations?

Yes, we have one and we use it on daily basis.

Q: If you had an easy opportunity to relocate the company, where would you like to be and why?

In the same place where we are now.

Q: Where do most of your sales come from: direct inquiry, referrals, ads, expos, etc.?

All you have named. Hard to pin out most important.

Q: Did COVID-19 seriously impact you?

In terms of volume, we had about 30% volume drop during spring and we expect some slowdown in winter too.

Q: What do you think of the electrification trend happing now in the automotive industry? How soon will electric cars take over the market? Aren't you afraid that this trend will put you out of work?

I think electrification will develop very rapidly and the speed will depend from political decisions. The question is whether electric cars will replace combustion engines completely in all segments. Probably not so quickly, however in cities, electric cars will dominate for sure.

Q: Some of the final questions coupled together: what are the tendencies on the market and what is the industry still lacking? Should we have some innovations?

It seems there are more than 2 questions. I can only say from our own experience: our industry is not much organized and not much protected. There are no relevant statistics concerning remanufacturing industry in Europe. The list of lacking things would be very long. From our statistics, we see transmissions with less mileage than it was before with older models and such trend includes all types: classic automatic transmissions, DSG, and CVT’s. More and more, we have to deal with the vehicle electronics, hardware and software systems – inside as well as outside the gearbox. You may ask: do we need more innovations for industry? Innovations cannot be too many. I think our industry is missing some preconditions for more innovations. I haven’t seen many innovations in our industry in recent years.

Most saving type of transmission

Sun, 19 Dec 2021 00:00:00 -0700

Most saving type of transmission

One of the most important questions that anyone planning to buy a car has to answer is: "which gearbox should I choose: automatic or manual?" Increasingly, car owners choose the automatic option, which is not surprising: driving a car equipped with an automatic is characterized by simplicity and convenience. Also, an important factor when choosing is the cost-effectiveness of use. In this article we will analyze, which of the units will allow the owner to save more on fuel.

Option # 1: Torque Converter automatic transmission

This is the most standard version of the automatic transmission, installed on most modern cars. The key feature of this type of transmission: the device does not have a clutch, its functions are performed by a Torque Converter. In terms of comfort of use, this option is probably the most convenient. However, in the process of using this type of gearboxes, the car owner faces a significant disadvantage – very high fuel consumption. Of course, car brands are constantly working to reduce this, but to date, not every manufacturer has managed to achieve acceptable results. As a rule, they try to solve the problem by installing quite complex devices – so-called blockers that require frequent and expensive maintenance. Accordingly, manufacturers install such devices only on the most modern and expensive cars.

Option # 2: CVT’s (also known as a stepless transmission, or variators)

The way CVT’s work is as simple as it is amazing. The mechanism consists of two shafts that have the shape of a cone. A belt or chain is stretched between them, giving traction. Thanks to this device, the gearbox and gear changes are incredibly smooth and unobtrusive. Owners of cars equipped with such devices note a certain unpleasant monotonous hum created by the gearbox, which, in principle, is not a huge disadvantage. Thanks to the complex variator system, the continuously variable transmission is one of the most cost-effective types of automatic transmissions.

Option # 3: Robotic gearbox

In the matter of fuel economy, the so-called “robots” are the undisputed leader. This is explained quite easily: there is almost no difference between the principle of operation of an ordinary manual transmission and a robotic automatic. The only difference between them is that the direct switching is performed not by the driver, but by a robotic system.

Of course, there is a difference between these two options. Gear changes performed by the “robot” occur with a significant hitch. Drivers who are used to other versions of gearboxes may initially react to this moment with some irritation. Nevertheless, this problem, apparently, will be fixed in the near future. Robotic gearboxes that take control of two clutch systems at once have already appeared on the market.

The principle of operation of such boxes is quite simple. Gears are divided into even and odd, and each of these categories is controlled by one of the clutch systems. This allows you to significantly increase productivity and reduce the pause between gear changes.

Signs of malfunction and failure of the transmission position sensor (switch)

Wed, 09 Sep 2020 00:00:00 -0700

Signs of malfunction and failure of the transmission position sensor (switch)

The main signs of the transmission position sensor malfunction are as follows: the engine does not start, the car does not move, the transmission switches to another gear when a certain gear is switched on, and the transmission goes into emergency mode.

The transmission position sensor, also called the transmission range sensor, is an electronic sensor that provides a signal about the gear selected by the driver to the transmission control unit (TCU). This means that the TCU controls the transmission shift according to the command given by this sensor.

Over time, the transmission range sensor fails or wears out. There is a number of signs indicating this malfunction or failure.

1. The Engine does not start, the car does not move.

Without receiving the “Parking/neutral” signal provided by the transmission range sensor, the TCU will not be able to signal the engine to start. That is, under these conditions, it is impossible to start the car engine. In addition, if the transmission range sensor fails, the TCU stops recognizing any incoming transmission signals. Therefore, in this case, the car just will not budge.

2. When you enable a given gear, the transmission is switched to another gear.

Sometimes, when the selector lever is moved to a certain position, the sensor signals a completely different gear. As a result, the TCU is controllably switched to a gear that does not correspond to the one selected by the driver using the selector lever. This is dangerous because it reduces the level of safety when driving and increases the likelihood of getting into an accident.

3. Transmission goes into emergency mode.

Some vehicles have the following feature: if the transmission range sensor fails, it will still be possible to turn on the transmission mechanically, but the TCU will not receive any data about this transmission. For safety reasons, a hydraulic or mechanical transmission lock is provided on one of the gears. This mode of operation of the transmission is called emergency mode. Depending on the manufacturer and the specific transmission version, the emergency mode may involve the third gear, fourth gear, or fifth gear, as well as reverse gear.

Detection of any of these signs indicates the need to contact a mechanic.

Transmission Solenoid Flushing & Cleaning

Mon, 31 Aug 2020 00:00:00 -0700

Transmission Solenoid Flushing & Cleaning

Over the years I have heard several different philosophies when it comes to flushing and cleaning solenoids. Most hydraulic solenoid test machines have either flush mode or an external cleaning system for solenoids. It is easy to think of it like you are putting the solenoid in a dishwasher of sorts and using hot ATF or solvent to blast away the dirt and debris. During my time at Zoom Technology, I visited several customers who would put solenoids in their Answermatic Solx machine and run them in flush mode for thirty minutes or more for each solenoid. Initially you might see a black puff of dirt come out, but after a few cycles the fluid remained “clean” coming out of the solenoid, but the thought was if some was good, more was better. In this article I want to take an honest look at flushing and cleaning of solenoids.

First, where does the dirt and debris come from that we are trying to flush out. When the transmission was initially assembled everything was clean and new, and all of the parts, the fluid, and the filter were clean and assembled in a clean environment. The “dirt” comes from normal wear of the parts inside the transmission. The obvious place would be from bands and clutches. If these slip or burn up, a lot of that material will come off will circulate throughout the unit. A second place would be any parts in the rotating assembly, bearings, bushings, and steels. Anything that is moving will exhibit wear over time and wear is basically material being removed that will again, circulate inside the unit. A third place would be from the valve body. We are all familiar with valve body wear and again as valves and valve bores wear, this is material being removed and circulating inside th e unit.

Outside of a catastrophic transmission failure, all of this debris is basically from normal wear of the transmission. Much of it will be caught by the filter or settle in the pan. We can break this material down into three types. The first is non-metallic (clutch and band material). The second is non-magnetic metallic material (aluminum and brass). The last is magnetic metallic material (and wear from steel parts such as bearings and steels). Think about a typical GM transmission pan with the donut magnet in one corner. When you clean the pan the first two items that are not caught in the filter will tend to coat the pan or gather to areas that does not have constant fluid flow during operation. The third item (the steel) collects on the magnet.

At its very basic form, what is a solenoid? Think back to grade school science class when you took a nail, wrapped a coil of wire around it, and applied a current to it. You made an electromagnet. The current in the wire wrapped around the nail magnetized it and you could pick up steel. The more wraps of wire and the higher the current, the stronger the magnet. The nail had to be steel as a piece of aluminum or brass would not do anything. A solenoid is basically the same thing. We have a spool of wire and a steel (or iron) core. When we energize the solenoid, rather than pick things up, we use this magnetic force to

Figure 1: An Electromagnet from Wire and a Nail

move a ball against a seat or move a valve as part of a regulating solenoid. Increasing current in the case of a regulating solenoid increases the force and allows us to control pressure with a high degree of precision. Think back to science class one more time when we made the electromagnet with the coil of wire and a nail. When you turned the current off the nail would lose most of its magnetism. It would, however, retain a very weak magnetic field even when the current was off. If we were lucky it would maybe pick up a staple, but this concept of becoming weakly magnetized is important to remember for the discussion on flushing and cleaning.

Figure 2: Shift Solenoids Assembly

I want to breakdown a simple shift solenoid. In Figure 2, you can see each part of a typical shift solenoid assembly. The small pin makes contact with the

ball. This pin is held towards the coil by a spring and moves to push the ball against the seat when the solenoid is energized and hence blocks flow. All of the fluid flow happens inside the plastic end that houses the ball and seat. Outside of the sleeve shown next to the coil, all the other items between the plastic seat and the coil are made of steel. The outside housing that holds this all together is not shown.

I want to identify three things when it comes to flushing and cleaning this solenoid.

1 – Most solenoid machines run a max temperature of around 160F. This is about the safe limit for an operator. In the vehicle, the transmission will generally run at 200F or more. While we are flushing with “hot” fluid, it is actually slightly colder than the normal operating temperature of the solenoid.

2 – With most solenoid machines I am able to vary the input pressure to the solenoid during a flush on the machine. This gives me the ability to set it higher than it normally sees in operation and the higher pressure can help to flush away accumulated dirt and debris in the normal paths of flow.

3 – If we look at the flow path of the solenoid, we can see with this one that we are only able to flush around the ball and seat area. The pin, spring, or the core inside of the coil is not in a flow path that would provide any real flushing. No matter what we do, these parts cannot be flushed and anything that has accumulated there, will remain.

The takeaway from this is that we have a limit to the flushing and cleaning ability for this solenoid. An initial burst of high-pressure fluid will clear out what it can in the ball and seat area, but as we can see anything further is not going to provide any additional flushing.

Figure 3: Regulating Solenoid Assembly

Let’s breakdown the regulating solenoid like we did the shift solenoid. As you can see in Figure 3, there are similarities to the shift solenoid. The key difference is that instead of a ball and seat, we have a pressure regulating valve that is controlled by current. As the current is varied to the solenoid coil, the diaphragm moves back and forth which causes the pressure regulating valve to move. There are also three distinct ports on this solenoid, the inlet, the outlet, and the exhaust port. Inside this solenoid there are also two distinct flow paths, one between inlet and outlet and one between inlet and exhaust. There are three things I’d like to identify when it comes to flushing and cleaning this solenoid.

1 – There are screens on all ports of the solenoid. Pressure regulating solenoids are generally regulate pressure, not flow. Flow is low through these solenoids and the screens will act as a flow limiter if you try to force fluid through with higher pressure. Unlike the shift solenoids we cannot force a large amount of fluid through to flush this solenoid.

2 – Take a look at the debris inside this solenoid. This was taken from a vehicle that had come in for a rebuild. It was a normal service, no catastrophic failure. The metal core that is part of the diaphragm is steel and (going back to our science class again) is going to be magnetic when current is applied and hold a weak magnetic field when off. Look at the debris stuck inside attracted by magnetism. Outside of cutting this apart, there no way you can realistically “flush” this debris out of this solenoid. Also, this debris is more or less held in place by the magnetic field anytime the solenoid is energized. Even with the solenoid off we will still have a weak magnetic field acting upon it.

3 – If we look at the flow paths of this solenoid, everything is happening on the end opposite as the coil. We have movement of the core inside of the coil up against the diaphragm, but there is not a flow path that would be able to provide any real flushing. This area of the solenoid cannot be flushed.

The takeaway from this is that flushing is probably even less effective than the shift solenoid. Most areas where debris will tend to collect cannot be reached or cleaned. We are also fighting against the magnetism and low flow through the solenoid even if we use a higher pressure to flush the solenoid.

I want to comment on degaussing. You can demagnetize (or degauss) steel by applying an AC current to either the wire wrapped around it or as a separate field. There have been several degaussing tools sold over the years that look like a circular wand and the concept was you used these to remove the magnetism on the internal steel components caused by the normal operation. Once you did this, any magnetic material inside would flush right out as we removed the magnetic field holding it in place. There are two things to keep in mind in regards to this.

1 – Magnetism and electromagnetics is complex. The principles and design are complicated, and a one size fits all tool that can degauss any solenoid regardless of how much or how little steel it has in it is a lofty task.

2 – Even if I have a degaussing tool that does the trick, the only way I can truly flush the solenoid is to move it from closed to open position. As soon as I apply a current to the solenoid to open or close it, I have reapplied the magnetic field and we are back to where we started, negating any degaussing effect.

Should we conclude that flushing and cleaning of solenoids are not worth the effort? Should we be wary of reusing them because there really is not a way to completely clean them? The fact is solenoids are designed to operate with some level of debris that accumulates over time. Between the transmission filter and the screens on the solenoid, anything inside is very fine and generally is going to collect in areas not critical to its function. What we should be looking for is that we do have proper solenoid function. Has this solenoid been compromised in a way that it no longer is able to function inside the transmission as intended? A ball and seat can wear or crack, a regulating solenoid can wear and either stick or not be able to repeatedly regulate pressure.

The best advice when it comes to flushing and cleaning of solenoids would be as follows:

1 – Clean the outside of the solenoid. As you can see in Figure 4, this regulating solenoid attracts debris on the connector end. We certainly do not want to introduce this into our freshly rebuild transmission or into our clean solenoid testing machine when we perform a solenoid test. This is one of the reasons why Hydra-Test offers a separate ultrasonic cleaner so that solenoids can be pre-cleaned before placing them in the HT Sol.

Figure 4: Dirty Regulating Solenoid

2 – Perform a flush as best we can. We will push some debris out, but letting it sit in a flush mode for more than a few cycles is not going to give much of an added benefit. The Hydra-Test HT Sol allows you to quickly test at a high pressure the first couple of cycles before dropping down to your test pressure and removes the need for a separate flush cycle.

Figure 5: Ultrasonic Cleaner option on the HT Sol

3 – Test the solenoid against a know good standard. Does it function properl y, and does it repeat each time we test it. This will identify any wear issues inside the solenoid and allow us to quickly determine if it can be reused or if it is time to recycle it. Also, if this solenoid is adjustable or needs calibration, you can perform this and bring the solenoid back into its factory specification. This is the reason why the HT Sol provides a graphical comparison so you can quickly determine if the solenoid you are testing matches a known good graph or not. Since it can be set to continuously cycle, you can bring an adjustable solenoid back into specification while it is running and watching for the graphs to overlay as it cycles.

This approach should give the best use of both your time and your equipment when working with reclaimed solenoids.

Figure 6: HT Sol Graphical Comparison

Valve Bodies – What is the Goal?

Thu, 27 Aug 2020 00:00:00 -0700

Valve Bodies – What is the Goal?

Over the past few decades valve bodies have become the single most complicated part of the transmission. The control has become very complex as we’ve gone from simple 4 speeds to electronically controlled 6, 7 and now even 10 speeds. They have also become one of the critical areas where wear causes other parts in the transmission to fail when operating pressures cannot be maintained. They are also the most difficult part to repair as this wear can be hard to see with the naked

Figure 1: 4L80E Valve Body | Figure 2: 6HP26 Valve Body

or untrained eye. Equipment such as the Hydra-Test VBT Deluxe gives you the ability to see this wear hydraulically and find the specific circuit issues as you can compare them against a new or known good valve body when operated under the same conditions.

But this does bring us back to what the overall goal is when it comes to valve bodies? Are we trying to build a better valve body, one that sits us back into the seat with each shift giving uncompromised performance? Are we trying to restore to a new OEM function? Are we just trying to get it out of our shop and down the road?

Figure 3: ZF 8HP Valve Body Under a Hydraulic Test

Before the advent of the electronic valve body, performance valve body kits were common. There were many performance kits that would modify the shift characteristics of the valve body and give you a firmer shift. I am sure more than one of us bought one of these in our younger years for our “hot rod” and loved the feeling of performance on each shift. Unfortunately, I’m also sure Mom thought otherwise, complaining when she rode with us “What’s wrong with your car? I thought you said you fixed it? This isn’t good for my neck!”

Modern valve bodies are really a part of a larger control system. Valve bodies are linked to TCUs and these TCUs have specific calibrations that have been developed for the engine/transmission combination in the vehicle as well as for the vehicle itself. Inputs from the engine and other controllers in the vehicle are taken into account as the TCU decides what gear to be in and when to upshift or downshift. The TCU’s uses complex feedback loops to determine if upshifts and downshifts happened correctly and if not they adapt to correct into the expected limits. When they cannot adapt any further, they signal a fault code and that is usually when we see it in your shop.

Given this, we can easily see how the concept of a shift kit for a modern valve body would work against the TCU and likely cause far more problems that it would fix. Today, changes to the shifting logic are accomplished by modifying the calibration in the TCU. While there are kits that do apply some form of modification, it tends to be more along the lines of creating better lubrication or a more stable pressure rather than changing the actual shift characteristics. With the valve body so connected to the other parts of the vehicle we are not trying to build a better or different valve body.

Just trying to get the vehicle out of our shop and down the road is probably not what we are after either. If the transmission barely makes it past the warranty period or worse yet fails before the warranty period is up, the customer will not forget and shift issues, even if they do not show up as fault codes will make for a very unhappy customer. We all know the saying “A happy customer will tell his friends, and unhappy customer will tell everyone!” Our goal is to build a good quality unit that we can stand behind and really offer the value that customers are seeking when they bring their vehicle to us.

That means that we should aim to restore the valve body to new OEM function, right? Any moving part inside the valve body will exhibit some wear over time, therefore the only way to restore function to brand new, would be to replace the valve body with a brand-new valve body. A more realistic goal on a rebuild is to find the areas of wear that have significantly impacted the function of the valve body and restore them as close as possible to OEM function. If solenoids are no longer able to regulate pressure smoothly and in a controlled fashion, they should be replaced. If springs are weak or broken and a valve is not controllable then the spring needs to be replaced. If a bore for a valve has worn and is no longer sealing properly around a valve, then the bore and valve needs to be addressed which usually requires reaming and the use of an oversize valve.

As we perform work on a valve body, keep in mind that the valve body is a delicate part of the transmission. Cleanliness is of paramount importance, as well as taking care of each part. Accidentally dropping valves from the valve body could bend them slightly and cause the to stick once back inside the valve body. Solenoids are also delicate, and care must be taken when handling them. Several years ago, I was visiting an OEM working on a machine for their remanufacturing line. They told me from time to time in their haste the forklift operators would “drop” a crate of new solenoids as they moved them from the warehouse. If this happened, they would not take the chance with them and the entire crate was taken to the dumpster.

Reaming out a valve bore is a process that must be done properly or you can cause more damage than good. If you take a new valve body and look down the bore, you see that it is smooth and machined with precision. When we ream a bore for an oversize valve, we need to get these same results. Think about the last time you were at a machine shop and saw parts in a CNC. What is critical for a machine shop when they are machining? Sharp cutting bits, the workpiece properly held in a fixture, the correct feed speeds, and plenty of lubrication/coolant while machining.

Figure 4. The reaming goal, a smooth bore on a new valve body

If you take a hand drill and a sharp drill bit and drill a one inch deep hole into a piece of aluminum, it may seem like you can drill a smooth precise hole if you are careful and delicate with it, but once you are done if you look at the hole, you will see that the bore isn’t smooth and shiny. You can see the marks where the drill bit cut as it went and wobbled as we tried to hold the drill steady. Granted, using a ream in an existing hole is a lot less aggressive than a drill bit, but this is where a good fixture, even feed speeds, and being flooded with coolant makes all the difference. If we end up with a bore that looks like the hole we tried to drill, you have poor sealing between the bore and the valve and could have the same or worse issues that the valve body originally had.

I really want to emphasis how critical flooding with lubrication/coolant is. I have watched reaming done by hand using a spray bottle and a couple of squirts of fluid. When you flood the area you are reaming it not only lubricates the ream to avoid sharp cut marks and chatter, but also washes the material we are cutting away from the bore to keep it from being drug around the ream in the bore as we continue the length of the hole. Again, think back to the last time you were at a machine shop and the kind of finish they can get on parts out of the CNC machines. We are aiming for this same type of a process on the valve body.

I also want to emphasis that the use of a fixture to help guide the ream. As steady as we all like to believe our hands are, a fixture to guide the ream and hold the valve body steady is necessary for accuracy when performing this operation. If you find yourself doing more than a few of a particular valve body, it might be well worth it to invest in a fixturing to be able to perform this on a milling machine. The valve body and reaming bit can be held true and feeds and speeds can be tightly controlled. This gives you the ability to get a high-quality ream every time.

The last step of the process is to check your work. There are a few different ways to check and see if the reassembled valve body is functioning properly before putting it back into the transmission and the vehicle. The best and most comprehensive way is to hydraulically test it in a valve body test machine

Figure 5: Hydra-Test VBT Deluxe

such as the Hydra-Test VBT Deluxe where you can simulate the real in vehicle operating conditions and be able to measure and graphically compare the valve body against a known good master valve body. This allows you to check many of the different circuits and compare against other units you have repaired using pressure gauges or a graphical display. This method allows you to record and analyze the pressures in the valve body and how they respond over time and to varying of the control solenoid current. Another method involves vacuum testing of individual circuits or valves on the valve body. There is plenty of information on this procedure if you do a quick google search, so I will not detail the process here. Lastly, you can just install it in the vehicle and take a test drive. If you were able to address all of the valve body wear issues, you should be able to clear all the codes and can run it through the learn cycle successfully.

Figure 6: Hydra-Test Graphical Pressure Comparison

One of the most challenging parts to this process is learning each different valve body and what typically wears on each unit. While there are some common things that seem to wear in every unit, each one has its own nuances which may differ depending upon if the vehicle spends its life in and urban or rural environment. As you work through this process, you also learn what areas consistently need to be addressed. While this can be painstaking in the beginning, the process does become easier with each valve body. Consistency in your repair methods and test methods is key to the process and achieving successful results that make both you, and your customers happy.

Solenoids - Replace or Reuse?

Mon, 24 Aug 2020 00:00:00 -0700

Solenoids - Replace or Reuse?

Solenoids can become a hot topic of conversation at transmission shops. Some say the best way is to treat them like a soft part and replace them on every rebuild, whereas other say that you can check them and only replace the ones that are faulty or worn out. The first group will say any reuse leaves you open to costly failure before the warranty period and can leave you with an unhappy customer. The second will argue replacing them all can be expensive, and on some models, you may end up with little or no profit left on a rebuild job.

Which is the stronger argument? Is there a right or a wrong way? Are both right?

Years ago, I was involved with the design of a high-end solenoid testing machine for an OEM Chrysler remanufacturer. They were specifically remanufacturing the rear wheel drive Chrysler units (42-48RE) and the machine we were commissioned to build would test the solenoids from all the cores that came in from the Chrysler dealerships across the country. Before we had even started the design of the machine, they had already completed a study to determined what percentage of the LU and OD solenoid assemblies were going to be recoverable and what percentage of the governor solenoids would be recoverable and could be reused once flushed and tested. The machine itself would perform a variety of OEM tests to the solenoids, and if they passed all of them, it would give green light that it was a good solenoid and could be reused. Since they were a large volume remanufacturer, the amount of money they would save by testing and reusing solenoids over the course of a year was in the hundreds of thousands and more than justified the cost of the machine.

If a scheme like this works for an OEM remanufacturer then it must be right for you? Well, there are a few things you need to consider.

First, you must properly test solenoids and verify their function. There are many inexpensive solenoid testers that may use air, are only an electrical check, or perform an incomplete hydraulic check. If they are not up to the task of properly testing solenoids, then it’s not a worthwhile investment. An incomplete test is almost as bad as no test at all. A high-quality hydraulic solenoid testing machine such as the Hydra-Test HT Sol are able to perform a consistent complete test on all modern solenoids. Having that capability does cost a set amount of money. Does your budget and volume allow for the purchase of a solenoid testing machine such as the HT Sol that can perform a complete, accurate, and repeatable tests?

Figure 1: Hydra-Test HT Sol Solenoid Test Machine

Second, do you have the technicians available to do solenoid testing and understand the process. Machines like the HT Sol can make the job easier since it uses a graphical overlay to compare the solenoid you are testing with a known good or known calibrated solenoid. There is still needs to be an understanding of the resulting graphs you get and what they mean when you compare them. Rushing through a test, not taking the time to understand how to test, or testing incorrectly is as bad as an incomplete test. Not only are you now paying for a testing machine, but you leave yourself open for comebacks because its not being used properly and eventually the test machine will migrate to the corner and collect dust.

Figure 2: HT Sol Comparative Graph

Third, and maybe most importantly, are the units you commonly see and work on going to give you payback that is worth the investment in both the technicians test time and the cost of a test machine? Not all parts of the country have the same mixture of vehicles and some shops specialize in certain units over others.

Let’s take a look at two different units. The first is a 4R70W which while it is an older unit, is still a relatively common in shops around the county. The second is the AS68RC/AS69RC, which is now the standard unit for Dodge trucks as well as used by other vehicle manufacturers.

Figure 3: 4R70W Solenoids | Figure 4: AS68RC Valve Body with eight solenoids

If we take my experience with the Chrysler remanufacturer, they had projections that upwards of 60% of the LU/OD (which are on/off) solenoid assemblies could be recovered and reused. On/off solenoids have fewer moving parts and realistically can last far beyond the life of the vehicle. The pressure regulating solenoid on the other had was closer to the 25% recovery rate. Since they typically are always moving they are more prone to wear and it was really the lower mileage solenoids that would still pass the tests and could be reused. These numbers are conservative so we will use them for the purpose of this example, assuming we can salvage 60% of on/off and 25% of pressure regulating solenoids.

If we look at a unit like the 4R70W, a complete set of solenoids off the shelf from a typical parts house runs about $50 for the on/off (shift) solenoids and $75 for the pressure regulating (TCC and EPC) solenoids. Averaging across all units at the percentages stated, you could potentially save $30 per unit for on/off solenoids and $19 per unit for the pressure regulating solenoids. At $49 savings per unit your payback time between a machine and a technician’s time could easily stretch into years. In this case it starts to make more sense to just replace the solenoids if the bulk of your work are 4R70W types of units.

If we look at the AS68RC, a complete set of solenoids off the shelf from a parts house runs about $360 for the on/off and $600 for the regulating. Again, averaging across all units at the percentages stated, you could potentially save $216 for the on/off (shift) solenoids and $150 for the regulating (linear) solenoids. This gives us $366 saving per unit. Suddenly the case to test and find and replace the faulty solenoids makes a lot more sense, especially if you see and service a lot of the later model units that have the higher number of these more expensive solenoids.

Another benefit for a solenoid test machine I have heard over the years from shops that test and reuse solenoids is that they also use the machine to test the new solenoids. Manufacturers, whether OEM or aftermarket, have extensive quality controls and test protocols in place to ensure that everything that goes out the door is a good quality product. However, there is always a chance that there could be a faulty part. There is also a chance that it was dropped in transport or somehow damaged before you received it. A quick test on a machine ensures that it does work and you can be confident that if you have problems once the transmission is back together, its not a solenoid issue as each one was tested and checked before you installed them.

At the end of the day it all comes down to dollars and sense. Is the investment in a machine and testing going to pay off and give you more profit down the road? You also need to have technicians that are comfortable using such a machine and are not afraid to scrutinize solenoids and err on the side of caution. Take a look at the units you commonly rebuild and run the numbers on the costs of solenoids. It should give a clear picture of what makes sense for you and your shop. At the end of the day the goals are to put out quality work, have happy customers, and be profitable.

Signs of the transfer case output shaft seal damage

Thu, 14 May 2020 00:00:00 -0700

Signs of the transfer case output shaft seal damage

Signs of the transfer case output shaft seal damage

The main signs of output shaft seal damage is stiffer gear changing, grating sound in the lower part of the car, and unexpected connection and disconnection of the all-wheel drive.

The ability to instantly switch from two-wheel to four-wheel (all-wheel) drive without having to stop the car and without locking the wheel couplings is an invention that many of us have long taken for granted, especially during snowfall. Most modern cars are equipped with a plug-in all-wheel drive system. The connection can be made manually by the driver using a switch or automatically, that is, when the on-board computer detects a decrease in adhesion of the wheels to the road surface due to adverse weather or bad road conditions. The mechanical unit of the car that performs this action is the transfer case, the output shaft of which transmits power to the driving axis. In some cases, the seals located between these components dry out, wear out, or are damaged. In this case, you must immediately contact a qualified mechanic to replace the seals, which will prevent further damage to the vehicle's drive system.

What is the transfer case output shaft seal?

The transfer case output shaft seal is used in the transfer cases of all-wheel drive cars, trucks, and SUVs. The transfer case has four modes of operation: rear-wheel drive, neutral, all-wheel drive with reduced gear and all-wheel drive. The design of the transfer case includes a downshift and chain transmission, the coordinated work of which allows performance of transferring power to both axles. The result of this is that the car becomes an all-wheel drive.

The output shaft connects the case to the axle. The transfer case output shaft seal is designed to prevent the transmission fluid from leaking out at the transfer case connection point via the transmission drive shaft. The seal also helps to avoid liquid leakage from the front and rear output shafts to the differentials, which allows drivers to continuously have well-oiled metal components.

Because of fluid leaking through the seals, proper lubrication of the internal components of the transfer case stops, which eventually leads to their wear and overheating. In this case, the transfer case will be a useless node that is not able to perform its function of controlling the four-wheel drive of the car. Over time, the transfer case output shaft seal may become damaged. Those signs described below will notify the driver of this. The following main signs indicate that a damaged transfer case output shaft seal must be replaced.

1. Complicated shifting

The seal helps to keep the working fluid inside the transfer case and, consequently, inside the transmission, thus ensuring its smooth and uninterrupted operation. Leakage through a damaged seal reduces the amount of fluid that is optimal for normal transmission operation. At the same time, there is also a drop in fluid pressure, which makes it difficult to change gears both for manual and automatic transmissions. If you experience some difficulty when switching to low or high gear, contact a qualified mechanic as soon as possible to check the car and fix the problem.

2. Grating sound at the bottom of the car

If the output shaft seal is damaged or worn out, unusual sounds can be heard from the bottom of the car. In most cases, the origin of these sounds is due to decreased amount of lubricant in the transfer case and, as a result, the friction of metal against metal. It is immediately clear to an experienced driver that metal screeching is a bad symptom, so when you hear the screeching from the spot where the vehicle’s transmission is located, contact a qualified mechanic as soon as possible.

3. Random connection and disconnection of the all-wheel drive, for no specific reason

In some cases, a decrease in the working fluid level may cause the all-wheel drive to be switched on and off at random during periods when only one of the modes should be supported. This is most often due to damage to the transfer case components that control this particular operation. Premature wear of these components is most likely caused by fluid leakage through the output shaft seal. If the liquid flows out through this seal, you will find a puddle of reddish liquid under the bottom of the car. This is nothing but transmission fluid, meaning that the transmission seal or gasket is damaged and must be replaced. If you find at least one of these warning signs, contact a qualified mechanic as soon as possible to replace the transfer case output shaft seal.

Tips to Select the Right Engine + Transmission Combination for a Truck

Wed, 26 Feb 2020 00:00:00 -0700

Tips to Select the Right Engine + Transmission Combination for a Truck

A fleet truck can be easily overloaded if it does not come with the proper powertrain (engine+ transmission) combination, thereby resulting in increased expenditures for maintenance servicing. The combination of these components plays a critical role for the truck performance capacity.

There is no standard solution when it comes to choosing the perfect powertrain for any truck. In this article, we will consider some helpful tips for owners of truck fleets on selecting truck components that have a significant impact on its performance, fuel economy and maintainability.

Application target

The first question that has to be clarified during the quest for a perfect powertrain system is the future application of the truck. When talking about the truck application, it is necessary to consider such factors as truck’s operating weight, max possible starting grade, and designated road surface help to specify what transmissions and engines will make your truck a real asset for any business. It should be noted that there are some transmissions that have certain restriction concerning the GCVW rates. All these important parameters mentioned above help to determine what kind of gearing and torque will be needed to operate most efficiently at specific cruise speeds.

Significance of Drivability

One of the most important aspects for truck drivers is the drivability of the vehicle. Depending on the application, it is necessary to take into account a wide range of parameters (smoothness of operation, maneuverability, speed of gear shifting, availability of creep mode) that ensure safe and efficient operation of the truck. For instance, it is extremely important for ambulance/fire and emergency vehicles to shift gears and pick-up the speed as fast as possible. In applications that are frequently exposed to stop-and-start traffic, it is necessary to pay attention to such aspects as clutch wear and driver fatigue (in such cases automatics may be more preferable).

Engine Displacement

The requirements imposed on the engine displacement greatly depend on the vocation of a specific truck. For example, trucks used for transportation of heavy loads may benefit from using a smaller engine displacement in order to save weight. Fleet managers should collaborate closely with dealers to determine the required engine size and to come up with the most efficient powertrain combination.

Manual vs Automatic

Selecting an ideal transmission type is crucial when considering a particular kind of fleet operation. When it comes to choosing between manual and automatic gear shifting units for trucks, it is necessary to keep in mind the following aspects: vehicle application, driver’s expertise, main characteristics of the engine (power, torque).

Truck drivers with different professional competence levels have recently been giving preference to automatics because of numerous advantages of modern self-shifting solutions. Automatics free drivers from the necessity to constantly engage the clutch pedal and shift gears manually, thereby allowing them to concentrate on the road and reduce the possibility of road accidents. As the global automotive industry gradually shifts to complete automation regarding transmission solutions, owners of truck fleets also cannot ignore the fact that new heavy-duty automatic gearboxes outperform conventional manuals in several important aspects (from performance capacity to maintenance cost).

Direct-Drive or Overdrive

Once the transmission type has been specified, fleet owners have to decide on a direct-drive or overdrive configuration. Until recently, overdrive options have been enjoying much more popularity. The thing is that previously the automotive market offered a limited number of direct-drive manuals on the market, and there was restricted axle ratio coverage to work with the direct-drive. But most of modern AMTs come in both direct and overdrive configurations. In fact, direct-drive units are more fuel efficient than their overdrive analogs.

Performance and Economy

Another important factor to consider when determining the main powertrain components is the priority between the performance and economy of the fleet truck. If good performance characteristics allow drivers to feel more comfortable on the road, high economy rates allow businesses to reduce the overall cost of operations. Achieving the right balance between these two important parameters is a big factor when determining the right powertrain setup.

Drivers

Driver satisfaction also should not be disregarded in this important design aspect. The right powertrain is not just about the performance and economy ratio. The correct combination should allow the driver to operate the truck in the most comfortable way possible, thereby avoiding excessive fatigue and increasing safety on the road. The competence and flexibility of drivers can differ, depending on the kind of fleet and peculiarities of the business. In fact, most of the drivers now are reluctant to drive manual trucks or simply don’t know how to do it. When considering the powertrain configuration, it is important for fleet owners to understand the level of driving skills of their employees.

Learn what it is like to drive a truck equipped with an AMT transmission and how’s it different from manual truck experience

Resale Value

Finding the appropriate powertrain setup also should be examined from the resale perspective. It is not a secret that major vehicle manufacturers gradually shift from manual to automatic transmissions, and it has a significant impact on the used vehicles market. Currently, automatic trucks have a higher resale value. When it comes to the engine, the choice between diesel and gasoline-powered engines depends on qualities for a specific business. While diesels ensure longer operation and better fuel economy, while gasoline engine vehicles are notable for a lower upfront cost.

Summary

All in all, a proper selection of the main powertrain components, namely engine and transmission, cannot be performed separately, as both components are interdependent when it comes to ensuring the highest performance and economy rates. Moreover, it should be born in mind that operating characteristics must match application peculiarities of the truck.

Unusual Gear Shifting Solutions in Hurst/Olds Сars

Thu, 06 Feb 2020 00:00:00 -0700

Unusual Gear Shifting Solutions in Hurst/Olds Сars

Today, it may be hard to believe today, but in the 80s, GM amazed the automotive market with cars with remarkable gear shifting mechanisms. These remarkable shifters allowed drivers of automatic cars to shift gears manually.

In 1968, Oldsmobile, in cooperation with Hurst Performance, produced a special version of the Olds Cutlass Supreme, named the Hurst/Olds. The most remarkable feature of this car was neither the paint job nor its powerful engine, but a Hurst dual-gate shifter that offered two algorithms of gear shifting. Before this unique project, George Hurst offered his remarkable gear shifting solution in 1963. It was supposed to make it possible for muscle-car drivers to shift gears more rapidly than with standard automatics.

Hurst dual-gate shifter

The Hurst shifting technology was based on a simple engineering concept - a shifter with 2 paths. The main left shift pattern was a conventional PRNDL (automatic) mechanism where you shift the lever in D gear and let the gearbox do the trick. It operated with medium line pressure and quite low shift points for comfortable driving. The other gate was intended for a synchronized manual control.

It implies that drivers of that time had a genuine choice. They could drive comfortably without troubling themselves with shifting gears (automatic mode) or to be more involved in the inner workings of their vehicle (manual mode). They could rely on the control system to do the job for them or to trust their own reflexes. It was also known as "His 'n' Her" shifter, as female drivers preferred to drive automatically, while men more often opted for the manual control.

In 1983 GM released the car with even more unusual gear shifting mechanism named Hurst Lightning Rods Triple Shifter. This technology has found application on the special Cutlass Supreme version.

Hurst Lightning Rods Triple Shifter

For futuristic gear shifter design, Hurst engineers took inspiration from the Lenco gear shifting technology that gained popularity in the world of drag racing. The design of Lenco unit comprises a series of planetary gear assemblies with a modular arrangement. The engineering structure of this transmission included a shift lever for each gear set. Hurst used this race-only setup as a basis and adjusted it to conventional automatics, making it possible for common auto enthusiasts to feel like a professional racer.

Lenco 4-speed drag racing transmission

The Lightning Rods solution was conceived to operate like any standard automatic gear shifter, with a well-known PRND pattern. The most peculiar part of its design lied in 2 extra levers. No wonder that such unusual design solution frequently confused young drivers, so Hurst made sure the system had a means of being driven even by inexperienced drivers: it was necessary to push the center and right lever forward to switch the gear shifting process into automatic mode.

Designed to be visually fascinating as Lenco, at the same time allowing manual shifting in the automatic car, the Lightning Rods system became a truly unique technology. These shifters sold in limited quantities by Hurst at speed shops throughout the US, but their expensiveness kept volume low. Moreover, this miracle of automotive engineering also found application in ’83-84 Oldsmobiles.

Check out this 3 lever shifter in action

Unfortunately, these 3-lever shifters turned out to be commercially unviable, and after ’83-84 Olds, this technology became a part of the automotive history. Hurst tried to revive this technology introducing aftermarket kits, but this idea also had poor success. Eventually Hurst shifting technology was replaced by more efficient shifters (Ratchet, Manu-Matic).

Too Much ATF in Automatic Transmissions: Causes and Potential Risks

Tue, 28 Jan 2020 00:00:00 -0700

Too Much ATF in Automatic Transmissions: Causes and Potential Risks

It is not a secret that the operability of modern automatic transmissions heavily depends on ATF (automatic transmission fluid), or more precisely on its condition, level, and temperature. Most of automatic transmission issues stem from ATF, thus repair professionals pay special attention to ATF and its timely change. If potential risks of lower ATF level are intuitively clear to most of car owners (oil starvation can lead to numerous malfunctions or even failure of the whole transmission unit), the situation with the fluid overflow may be misleading.

Some inexperienced car enthusiasts mistakenly believe that if the low ATF level can be extremely harmful for the transmission, then it is better to fill as much lubricant in the automatic transmission as possible. But it is a serious misconception. In this article, we will discuss negative consequences of ATF overflows for automatic transmissions and how to solve this problem.

How it happens?

When performing regular maintenance procedures, which necessarily include the ATF level check, you may unexpectedly find out that the ATF level is somehow above the norm. As a rule, this situation frequently occurs after adding the fluid filling-up or its complete change. Less often, this issue can be caused by some malfunctions in the transmission unit. It should be noted that it would be a mistake to measure the ATF level without the transmission warm-up.

Consequences of ATF overflow

In some automatic transmissions, too much ATF can lead to instant transmission faults that manifest themselves in jolts, kicks or error codes, while in some cases transmissions can continue operating without any symptoms of the existing problem. Anyway, it is important to understand that the ATF level must be kept normal, avoiding its scarcity or excessiveness, even if the transmission operates normally. The thing is that ATF, in addition to its main functions (lubrication, protection, cleaning and heat removal), also plays the role of a working element of the transmission. The process of torque transfer in the torque converter is implemented by means of the transmission fluid. Moreover, ATF is a key element in the valve body operation, as its circulation via valve body channels ensures automatic gear shifting.

Now let us pay more attention to actual consequences of the transmission fluid overflow. First of all, in the process of operation, ATF heats up heavily and its volume increases as well. If there is too much fluid in the transmission, then it usually starts foaming, causing leakages in gaskets and seals. Thus, we can say that overflows can lead to potential faults in air-tightness and emergence of leakages. Moreover, ATF can leak through the dipstick.

Learn more about the symptoms of ATF overflow and possible solutions

If leakages are unpleasant, but not critical, then other “hidden” consequences of the fluid overflow can bring much more harm. For instance, the pressure of the foamed fluid is not enough for proper operation, as it leads to deterioration of lubricating qualities and slippages of friction elements. Bubbles noticed on the dipstick during the ATF level check, can become an additional symptom of the fluid overflow and its foaming. Excessive fluid also can reach seals and damage them.

As a rule, fluid overflows manifest themselves in kicks and jolts in the automatic transmission during shifts, consequently leading to wear of transmission parts and poor cooling of the transmission unit. In this case, it is necessary to check the fluid level after the transmission warm-up. If the fluid level is too high, it should be adjusted.

How to drain excessive fluid

There are several ways to remove excess oil from an automatic transmission. Many transmission specialists use a special fluid syringe. It is just necessary to put a thin rubber tube on the syringe and then insert this into the dipstick hole and pump out excessive fluid.

If you have to deal with so-called maintenance-free transmission that does not have a dipstick, then it is possible to drain excessive fluid after removing the external oil filter. It is also possible to disconnect hoses from the radiator cooling system or unscrew the drain plug. It is also important to remove the excessive fluid by parts, constantly checking the fluid level during the process.

Useful tips

Before checking the fluid level, it is necessary to warm-up your car properly. For this purpose, it is necessary to drive your car for at least 10 km. Then the car should operate at idle speed for about 5 minutes, after that it is necessary to shift through all gears with the help of the shift selector, lingering at each gear for 2-3 seconds. Do not shut off the engine and leave the selector in P mode. After that, you can get out of the car, remove the transmission fluid dipstick, wipe it with a clean rag and insert it back firmly for 2-3 seconds. Then the dipstick can be removed once again and check the fluid level.

When examining the dipstick, do not forget that the normal fluid level must be between marks HOT and COLD. A shift towards HOT by 2-3 mm is allowed, but not higher. In some cars, there is only one mark and in such cases this mark should be used as an orienting point. For some cars (especially models equipped with so-called maintenance-free transmission without a dipstick), specialists recommend filling in the same amount of fluid as has been previously drained. When changing ATF, do not forget to use the fluid that is recommended by the manufacturer of the car or transmission unit itself. If you decide to use an alternative ATF variant, then make sure that it complies with all tolerances and recommendations specified by the manufacturer in the manual.

All in all, it can be concluded that it is extremely important to avoid both the low fluid level as well as its overflows. To avoid serious trouble with the transmission, it is necessary to devote considerable time to examining the car manual and learning peculiarities of ATF change.

Mercedes transmission typical problems

Wed, 22 Jan 2020 00:00:00 -0700

Automatic Transmissions from Mercedes and their Typical Repair Issues

During most of its history, the German automaker Mercedes has been independently developing and manufacturing transmission solutions (manual as well as automatic transmissions) for its cars. As a rule, Mercedes transmissions are considered by many as a benchmark of quality and reliability. At the same time, Mercedes engineers always try to implement the process of gear shifting in a special way, which fully reflects the philosophy of the company.

However, like any other piece of machinery, Mercedes automatic transmissions should be operated in accordance with specific technical rules. Mercedes automatics require regular diagnostics, maintenance services, and professional technicians recommend car owners to avoid aggressive driving, slippages, etc. Otherwise, even the most reliable Mercedes transmissions will get out of order pretty fast. In this article, we will consider the development history of Mercedes transmissions and their typical repair issues.

Bits of History

It is believed that the 1-st Mercedes-Benz equipped with an automatic transmission was the Mercedes-Benz 770 (also known as Grand Mercedes), which was produced during 1930-43. Initially, this model was equipped with a 3 speed manual transmission, but since 1938 it was produced with a 4 speed overdrive manual transmission.

Mercedes-Benz 770

First automatic Mercedes models hit the automotive market in the 1950s. Here we should mention the Mercedes-Benz 300C, which after some restyling in 1955 received a 3-speed hydro-mechanical automatic transmission from BorgWarner (marked as DG 150M). In 1957, the Hydrak transmission was optionally available on 220S and 219 models. It was a 4-speed manual transmission with a gear shift gate located on the steering column. The clutch of this transmission was complemented with an electro-vacuum servo mechanism produced by Fichtel & Sachs and a hydraulic coupling provided by Daimler. Cars equipped with the Hydrak unit didn’t have a clutch pedal, and shifts were performed with the help of a lever mounted on the steering column.

Check out Mercedes Ponton equipped with Hydrak transmission in action

Mercedes presented its own-produced hydro-mechanical automatic transmission 722.2 in 1961. This transmission found application on W111 220 SEB/300 SE models. Instead of torque converters applied in modern automatics, this transmission was equipped with a hydraulic clutch/coupling. This transmission had been produced until 1983. In 1967, Mercedes released an upgraded version of this transmission with a torque converter (722.1). This transmission found application in the W116, W123, and other models. In 1964, Mercedes engineers developed an enhanced 4-speed hydro-mechanical transmission specifically intended for the 6-seater Mercedes-Benz 600. In this transmission solution the number of planetary gears was increased from 3 to 6. In 1970, the German car manufacturer provided a special 3-speed transmission unit (722.0) that was able to operate in pair with V8 engines. A special improved transmission version (722.003) was developed in 1975 to be coupled with the 6.8-liter engine installed in the 450 SEL 6.9 model. This transmission unit still impresses transmission repair experts with its durability when compared to other hydro-mechanical automatics.

In 1981, automatics of the 722.0 – 722.2 Series started to be gradually replaced by the more advanced 722.3. This transmission was broadly used in many passenger cars produced by Mercedes. For instance, this unit was installed in all versions of the W124 model, except for a version equipped with a 3.2 gasoline engine. The 722.3 unit also found application in the W126 series of S-Class automobiles (including 560SEC and 560SEL) as well as in its successors from the W140 Series. High reliability of the 722.3 transmission was proved by the fact that it had been installed in the 1-st Mercedes SUV.

In 1983, Mercedes presented the 722.4 transmission, which, in terms of design, was a smaller copy of the 722.3 transmission. This automatic transmission was specially designed for the Baby-Benz model. The first 5-speed Mercedes automatic transmission (722.5) was built in-house in 1989. This transmission was installed in E-class and S-class models (W124, W140).

The release of the next Mercedes transmission (722.6) became a real breakthrough in evolution of Mercedes transmission. This transmission (also known as Steptronic) was the first solution, where Mercedes engineers managed to practically implement electronically controlled gear shifting and the torque converter lock-up system. The 722.6 transmission became the main option for passenger car models produced by Mercedes from 1996 to 2003. Before the release of the 7-speed 7G-Tronic (722.9) transmission in 2003, the 722.6 unit was successfully utilized in W211, W203, and W220 models.

722.3, 722.4, 722.5 – design simplicity is a key to reliability

It is hard to find any modern transmission unit that can compete with the 722.3 transmission developed in the 80s in terms of the service lifetime and reliability. Perhaps, on the one hand, it can be explained by the fact that the 722.3 design is quite simple. On the other hand, it can be assumed that these old transmissions were designed and assembled with higher quality compared to modern analogs. In general, 722.3 automatics were extremely reliable were able to operate without problems for decades, sometimes covering up to 1 mln km before the first overhaul.

722.3

Four-speed Mercedes automatics (722.3/722.4) with purely hydraulic control frequently get out of order because of improper operating conditions and non-compliance with service intervals (ATF change and other maintenance services). According to the factory operating rules, ATF should be changed together with the filter each 60 thousand miles. Nevertheless, the resource of these robust transmissions has its limits – old automatics start having issues with friction discs (linings come off) and the brake band plates get damaged.

In terms of design, the main drawback of the 722.3 transmission is its vacuum control system. Structurally, this transmission mechanism is integrated into a single vacuum system of the vehicle. Thus, even the slightest leak in vacuum lines of old Mercedes cars leads to ATF pressure losses, resulting in possible hard shifts and slippages during upshifting.

722.4

When we are talking about the 722.4 unit, this transmission is a smaller version of the 722.3 solution, as mentioned above, thus these transmissions have similar strengths and soft spots.

The Mercedes-Benz 5G-Tronic (also known as 722.5) is known to be quite reliable, but transmission repair specialists frequently have to deal with the failure of 5-th gear in this transmission. The problem is caused by transmission fluid shortages or pressure issues. This problem can be detected in the following way: when the transmission shifts from 4-th to 5-th gear, driver can notice unusual increase in the RPM rate. If the problem is not addressed timely, 5-th gear will stop working with time, as friction discs get burnt.

722.5

Then, wear debris from burnt friction discs contaminate the whole transmission system, clog the transmission filter. The pressure in the system drops, increasing the overall wear of the transmission unit and eventually resulting in the transmission malfunction. To preserve the Mercedes 722.6 transmission from premature failures, it is necessary to replace the planetary gear and the package of friction discs of 5-th gear. Moreover, “old” 722.5 transmissions are quite sensitive to overheating. ATF leaks lead to the oil starvation and consequent damage of friction mechanisms.

722.6 worth a special mention

As all conceptually new solutions, the 5-speed automatic transmission 722.6 (also known as Steptronic) gave birth to numerous arguments and myths on the internet. In terms of design, this transmission turned out to be much more complex than its predecessors, as it is the 1-st Mercedes transmissions equipped with an electro-hydraulic control system. It allowed Mercedes engineers to significantly increase the speed of gear shifting and improve the quality of this process.

722.6

Despite its technical complexity, this transmission can be hardly called structurally unsuccessful, but it has its own specific design features that require experience and some special skills from technicians when it comes to diagnostics and repair services.

Most of the problems in this transmission occur because of ATF leaks. If the fluid penetrates in the valve body, the electronic control unit may get out of order. The transmission can also be damaged in cases where antifreeze substance gets mixed up with ATF. There are repair recommendations depending on the glycol concentration in ATF. Under the influence of glycol, the material of friction discs may swell. In this case, it is necessary to eliminate the radiator leak, causing the mixture of antifreeze and ATF. Another problem that can lead to the control system failure (and its subsequent replacement) is the failure of the RPM sensor integrated in the control unit.

Common problems for 722.6 units (its early versions) lie in wear of thrust bearings in planetary mechanisms of the transmission and wear of slide (sleeve) bearings in the turbine shaft of the torque converter (in 1999 this problematic component was replaced).

With time, all 722.6 transmissions with high mileages are affected by wear of the torque converter lock-up mechanism. Wear debris of friction linings of the lock-up clutch contaminate ATF. The transmission fluid mixed with frictional dust leads to wear of solenoids (as well as valve body), and friction mechanisms of the transmission. The result is always the same – a slow “death” of the transmission. The torque converter overrunning clutch also can be a source of trouble in “old” 722.6 transmissions.

722.6 cut-away

It is interesting to point out that initially the 722.6 transmission model was supposed to become a maintenance-free transmission solution, i.e. it was supposed to be unnecessary to change ATF during the whole service life of the transmission unit. Thus, all Mercedes models equipped with this transmission initially didn’t have a dipstick. But with time, it turned out to be just a marketing trick.

Currently, even official Mercedes service centers no longer say about the lack of maintenance intervals related to ATF change and recommend car owners not to disregard this important maintenance operation (change fluid each 60.000 km). When complying with rules of operation and ensuring timely replacement of spare parts, this popular automatic transmission will easily reach a standard for Mercedes mileage (500.000 km).

722.8

When it comes to Mercedes CVTs, namely the 722.8 transmission (also known as Autotronic), it should be noted that this transmission didn’t gain popularity among Mercedes admirers, thus remaining the only Mercedes CVT transmission. Specialists often encounter the following issues in 722.8: wear of cones, belt, oil pump, and valve body in the CVT. It should be remembered that the repair of Mercedes transmissions frequently turns out to be quite expensive, and when we are talking about the 722.8 transmission, the repair process becomes more complicated because of more sophisticated design of this unit.

Recommendations

In reality, Mercedes automatics gained recognition as reliable and maintenance-friendly solutions. In most cases, Mercedes cars come to repair shops with transmission issues because of non-compliance with the rules of operation, ill-timed maintenance, or natural wear of its spare parts. Owners of Mercedes cars should not disregard standard maintenance services (ATF change, replacement of spare parts), relying on “invincibility” of their transmissions. It is important to remember that service intervals specified by the manufacturer are usually based on laboratory studies (operation under standard conditions). In reality, cars are frequently exposed to severe operating conditions (temperature fluctuations, rough roads). Therefore, in most cases, it is necessary to reduce intervals between ATF changes and replacement of spare parts.

Learn how to change ATF in 722.6

Responsible drivers have to monitor the transmission condition, perform diagnostics, and change ATF, even if it is not specified in the manual. Even if the transmission unit operates properly, regular checks can help to detect some hidden malfunctions and prevent more serious issues in the future. Monitoring of ATF level and regular cleaning of the transmission system will help to prevent overheating of the transmission unit. Transmission fluid should be changed each 60,000 km or at most 80,000 km. If the mileage in the car is over 100,000 km and it frequently operates under severe operating conditions (aggressive driving, poor roads), then it is recommended to reduce service intervals to 40-50,000 km.

Howard Frederick Hobbs and His Transmission Heritage

Tue, 14 Jan 2020 00:00:00 -0700

Howard Frederick Hobbs and His Transmission Heritage

Automotive engineers have always been involved in a constant search for an innovative solution that can solve the problem of varying the gear between the driving and the driven members in a vehicle automatically and in an infinite number of different ratios. Long before the arrival of continuously variable transmissions (CVTs), engineers had something to offer in this field. In this article, we will consider a rich heritage of transmission solutions left by Howard Frederick Hobbs, a South-Australian pioneer of the automotive transmission industry.

Born in 1902 in Adelaide, South Australia, Hobbs started driving motorcars from an early age and dreamed of inventing a technology that would exclude the necessity for gear changing. He spent seven years working on his gearless (variable) until he had a working model operating in a "baby Austin" car. His invention gained the support of academic staff from Adelaide University. In 1931, a talented automotive engineer established his own company named Hobbs Gearless Drive Ltd to promote his innovative solution, to market the device, and to manage the patent rights.

The key component of this transmission is an epicycloidal (planetary) gear set composed of a disk holding 2 planet pinions (wheels) on each of which there is an eccentric mass, throwing the pinions markedly out of balance. Meshing with the planet wheels is a sun gear attached to a shaft, which in turn is connected to the front end of a long laminated spring shaft. This shaft, paired with a special roller clutch, plays the role of what, in other types of infinitely variable gears, would be the ratchet gear, or "mechanical valve".

Hobbs didn’t manage to convince automakers to give a chance to his variable transmission, the thing is that a free-wheel clutch (also known as a ratchet) included in the design of this transmission was considered by many experts as a failure-prone element of this device. Other enthusiasts with similar solutions also did not become a success at that time. As a result, the company was closed in 1941.

However, Hobbs didn’t think of giving up and in 1946 he, with the support of a wealthy industrialist, founded Hobbs Transmission Ltd. Hobbs completely abandoned his gearless technology and devoted all his efforts to development of another transmission technology that was named “Mechamatic”. This automatic transmission combined epicyclic (planetary) gears and hydraulically operated friction clutches. This lightweight transmission had 4 forward gears, unusual at that time, and could be installed in compact cars. Famous automakers of that time created numerous vehicle prototypes equipped with the Mechamatic unit, but the only one to reach the stage of a fully operating pilot model was the Lanchester Sprite, produced in 1955 by the Birmingham Small Arms (BSA) Co. Ltd. This model was supposed to become the first British light car equipped with an automatic transmission, if it had reached a large-scale production. However, due to financial difficulties, BSA soon shut down the project.

Westinghouse Brake & Signal Co. Ltd acquired BSA’s assets in Hobbs Transmission and, planning its application in the Ford Cortina, constructed a plant in Manchester to produce the Mechamatic. However, later Ford abandoned this idea, and Hobbs Transmission ceased to exist. In the 1960s Hobbs’s son David showed a good result at the international racing competitions, driving a Lotus Elite equipped with the Mechamatic technology.

In 1965 and Hobbs and his son John opened a workshop. They decided to improve the original concept of the gearless solution, but this time making it hydraulic rather than mechanical. Hobbs obtained an Australian patent for this technology, but like other similar technologies of that time it didn’t find its place on the market.

Although considered by many as a genius in the field of automotive transmissions, Hobbs didn’t manage to develop a commercially-viable product for the automotive market.

Remarkable Features Implemented in Modern Manual Transmissions

Mon, 13 Jan 2020 00:00:00 -0700

Remarkable Features Implemented in Modern Manual Transmissions

Nowadays, transmission technologies are developed with unprecedented pace, and manufacturers can offer more and more sophisticated solutions that ensure much faster gear shifting capacity, fuel efficiency, as well as a general comfort while driving. No wonder that classic manual transmissions or even some automatic transmissions get replaced by more advanced dual-clutch or hybrid transmissions.

We get used to newspaper headlines such as “Manuals are dying”, “Stick shift is going extinct”, “Stick shift sales keep falling”, but it should not be assumed that the development curve of manual transmissions stopped at 4-5-speed units without any smart technologies. In reality, modern manual transmissions also can be equipped with a variety of remarkable features. Thanks to the use of advanced technologies, performance capacity of efficiency of modern manual transmissions can become a pleasant surprise for auto enthusiasts. In this article, we will consider some advanced features implemented in modern manual transmissions.

Downshift Rev-Matching

The art of heel-and-toe shifting was once a precondition to use the performance capacity of the transmission unit, but downshift rev-matching feature now helps even young drivers to feel like a professional racer.

Check out this great video on Rev-Matching from Engineering Explained

Used mainly on performance-oriented vehicles, this technology automatically matches engine RPM rate to the engaged gear for ideal downshifts. This feature is especially useful for racing cars, but it can also become a pleasant bonus for some manual road cars.

No-Lift Shifting

Even young drivers know for sure that when driving a manual car and performing gear shifts, it is necessary to lift your foot off the gas pedal every time you press the clutch and then hit the throttle again as you depress the clutch pedal. However, this simple rule doesn’t work when we are talking about the Cadillac ATS-V and its 6-speed gearbox. This model comes with a no-lift shift feature that allows the driver to change gears without depressing the gas pedal. The 2019 model year is the ATS-V’s last, and it is still unknown whether this remarkable feature will be integrated into future manual Cadillac models.

Interior of 2019 Cadillac ATS-V

At the same time, some experts claim that this feature is not really good for your car. The thing is that without applying the clutch, the driver forces the synchronizer to perform functions it's not supposed to do. That is, adjust the wheel speed to the transmission speed. While it may add some extra power in the moment, there may be a negative impact on the clutch unit.

Hill Start Assist

Hill Start Assist (HSA) isn’t a new technology for manually shifted cars – not even remotely. The first modification of HAS was introduced in 1936 and it became extremely useful in a certain situation on the road. It comes into play when the vehicle standing on the slope has to drive off again. It helps the driver to prevent the car from rolling back on a hill and hitting the vehicle standing exactly at the back.

It is no doubt that quick and right actions of the driver can exclude any rollbacks without resorting to the HAS feature, but even the smallest mistake can lead to the engine stalling. HSA gives the driver more time to start off by briefly holding the brakes after you’ve released the brake pedal. To put it simply, the modern HSA feature operates by means of 2 sensors, in pair with the brake system on the car. The 1-st sensor monitors the forward-facing incline (nose higher than tail) of the car, while the 2-nd is a disengaging mechanism.

Smart Technology

In view of the fast pace at which automotive technologies and markets advance today, more and more vehicle components (automatic transmission, dual-clutch transmission, hybrid transmission) operate on the basis of advanced software algorithms. The Toyota Corolla Hatchback’s manual gearbox has also become smarter thanks to the use of sophisticated features. Downshift rev-matching is one such feature, but the car can also automatically optimize engine RPM rate to minimize lurching during untimely shifts.

Additional Forward Gear

Compared to 8-, 9-, 10-speed automatics, designs of manual units have been limited in the number of forward gears, but cars like the Porsche 911 come with 7-speed manuals rather than standard 6-speed units. What’s the point? The extra 7-th gear is quite tall, which ensures improved gasoline consumption during highway cruising. The 7-speed manual solution is a revolutionary addition to a long history of exceptional standard transmissions.

Engine Stop-Start

Engine stop-start feature has come into common use in automatic cars. Automakers put in great efforts to squeeze extra efficiency from IC-engines, but they’ve also managed to adopt this technology in manual cars, too. But in reality, this tech frequently turns out to be quite annoying for owners of automatic cars, as many drivers claim that it switches off engine power at every traffic light, causing driver’s discomfort.

On manually-shifted cars, stop-start is actuated as follows: Stop car and press clutch - move gear lever to N gear - release clutch - then the engine stops. The engine will not stop if the car is running, even if the mentioned steps are executed. The engine restarts when the clutch is pressed prior to selecting a gear to move the car.

Gear-Position Indicator

Upshift indicators have been available for car engineers for some time, but such fuel-saving features are not so well-received by enthusiasts who like to use performance potential of their engines to the fullest. However, another readout technology integrated in modern manually shifted cars — the gear-position indicator — is a bit more useful, especially as manuals have gained extra forward gears over the last years.

All in all, it is hard to argue that manual vehicles continue losing their share on major automotive markets, but there is still a significant fan base of cars with a classic stick shifter, and who knows, maybe one day the list of technologies described above will be added with a new one that will breathe new life into manual cars.

How Porsche Taycan Turns Out to Be Faster than Tesla Model S on Race Track

Tue, 07 Jan 2020 00:00:00 -0700

How Porsche Taycan Turns Out to Be Faster than Tesla Model S on Race Track

Recently, Top Gear arranged an exciting speed competition between the Tesla Model S Performance and the new Porsche Taycan Turbo S. Despite the fact that the Tesla had an edge in weight and power, the German car came out victorious in the 0-60 sprint. Seems strange? Don’t be surprised, as the victory in this kind of competition requires something more than just power and weight. A well-known youtube channel Engineering Explained gave a clear technical explanation of this result in one of its latest videos.

Check out the full video from Engineering Explained

On the dragstrip, the Taycan posted the time of 2.61 seconds, while the Model S crossed the finish line at 2.68 seconds. It is interesting to point out that Porsche’s result matched the time specified by the German automaker to cover this distance (2.6 seconds), while the Tesla ran behind schedule of 2.4 seconds. The Porsche's quarter-mile was done in 10.69 seconds vs the Tesla's 11.08.

The secret of this result lies in one important powertrain difference between these two great cars, namely the transmission unit. The thing is that the new Taycan features a two-speed gearbox at the rear axle rather than a single-speed unit installed in most EVs, including the Model S. This multispeed solution is assumed to improve performance capacity at higher speeds.

Take a more detailed look at the Taycan’s transmission

When it comes to real driving, 1-st gear stays engaged up to 62 mph, meaning it can increase the torque factor before switching to the more fuel-efficient 2-nd gear.

Full review of this exciting competition from TopGear

Thanks to the use of numerous mathematical calculations, the host of EngineeringExplained channel makes it abundantly clear how the Porsche is able to give more wheel torque and thus more g forces in that 1-st gear, despite stated advantages of the S Model. Once the car comes to the 62-mph mark, the torque rates for either gear get aligned, so the car shifts to 2-nd, allowing the rear e-motor to operate with lower RPM rate.

The Model S, in turn, has just one, unvaried ratio to employ. Thus, it has to apply its single ratio at different speeds. It cannot increase its wheel torque when needed like its Porsche opponent, implying the weaker performance capacity on the track.

What are Paddle Shifters: Design Peculiarities and Principle of Operation

Thu, 02 Jan 2020 00:00:00 -0700

What are Paddle Shifters: Design Peculiarities and Principle of Operation

While cars equipped with manual transmissions gradually become outdated, many car manufacturer still integrate the feature allowing drivers to shift their own gears. How it can be implemented in automatic cars? The answer is simple – easy-to-use and efficient paddle shifters.

It is not just some sophisticated technology that looks awesome in sports cars, as today it is more and more frequently used as the method of controlling the engine power in a car. The paddle shift system is the main element in a semi-automatic vehicle control system. This mechanism can be one of the most enjoyable ways to drive a car. In this article, we will take a closer look at this remarkable technology, its design peculiarities, principle of operation, and benefits that allowed this remarkable system to gain popularity among auto enthusiasts.

Origins

The idea of using this handy gear shifting mechanism was firstly implemented in motorsports, namely in F-1. In the late 1980s, Ferrari became the 1st team to enjoy benefits of this technology in practice. After proving its efficiency and ease-of-use, this technology was adopted by other F-1 teams, and after a while paddle shifters appeared in conventional road cars.

Importance of Manual Mode in Automatic Transmissions

Thu, 19 Dec 2019 00:00:00 -0700

Importance of Manual Mode in Automatic Transmissions

Modern automatic transmissions are justly considered by many to be more comfortable and efficient gear shifting solutions, and no wonder that major car makers give preference to advanced automatics over conventional manual transmissions, thereby gradually making the latter a relic of the past. The trend of shifting to automatics is especially vivid on the US market, where the take rate of manual cars hardly reaches 2%.

Rapidly growing share of automatic transmissions in modern vehicles made it possible to increase the level of comfort on the road, optimize the process of gear shifting and fuel economy, and to implement some features related to the road safety. All these benefits are particularly important on urban roads with heavy traffic. But why designs of automatic transmissions still include a manual mode of operation?

Transmission manufacturers include this feature for a reason, as drivers frequently have to deal with some situations on the road, when it is necessary to shift gears manually. In this article, we will consider how this feature can be implemented in automatic transmissions, and more importantly, when this mode of operation should be engaged.

Ways to implement a “manual mode” in automatic transmissions

Most of all automatic transmissions, in one way or another (Tiptronic, Overdrive, kick-down etc), allow owners of automatic vehicles to simulate the sequential manual control, as the actual gear shifting is still fulfilled by the TCM, while the driver decides what gear should be engaged.

Activating manual mode is not the same for all brands. Switching to the manual mode and further control in automatic transmissions with a Tiptronic function is implemented by moving the shift lever into D and then move the lever to the Tiptronic shift gate marked with symbols “+” for upshifting and “-“ for downshifting. In some cars, manual mode can be actuated by means of paddle shifters.

Some automatic cars have an operating mode named “overdrive” (or O/D). This mode is engaged when the driver presses a special button located on the gear lever, thereby triggering forced engagement of the highest gear.

Shift Lock Release Button in Automatic Transmissions

Mon, 16 Dec 2019 00:00:00 -0700

Shift Lock Release Button in Automatic Transmissions

It is well-known that modern automatic transmissions are much more complex than conventional manual transmissions, and therefore in addition to standard driving modes like D (Drive) and R (Reverse) automatics frequently have more additional features and operating modes.

Owners of automatic cars frequently cannot fully control the operation of complex automatic transmissions, thus manufacturers have to develop special features, which will help drivers to handle different situations on the road. In this article, we will consider a Shift Lock Release (or simply Shift Lock) button that frequently raises a lot of questions among young drivers.

Automatic transmission technologies never standing still

Nowadays, automatics are equipped with complex control systems and have many different modes of operation depending on specific operation conditions and it seems like automotive engineers are not going to stop there. Automatic transmissions and their control modules are constantly upgraded, more and more electronic components are integrated in their designs, thereby strengthening positions of automatics on the world market. But the excessive use of electronics has its drawbacks. Different microcircuits, sensors and board components, wiring and other elements frequently fail because of vibrations, moisture, overheating, etc. To adjust the performance of the gear shifting unit to the liking of drivers or to the road conditions, engineers came up with additional modes that help to deal with different situations on the road and reduce load on the gearbox.

In addition to the main modes (P-R-N-D), automatics frequently have the capacity to lock the upshifting (when the gearbox cannot shift higher than 2nd gear or constantly operates on 1-st gear). There are modes that allow the driver to decide when the gear shifting should take place, namely Overdrive and Tiptronic. Overdrive mode allows the driver to put in the highest gear. Tiptronic mode is implemented by moving the shift lever into a second operating plane of the shift gate marked with symbols “+” for upshifting and “-“ for downshifting, thereby allowing drivers to decide what gear should be engaged.

That’s how Tiptronic is implemented in automatic transmissions

Moreover, owners of automatic cars also can notice other buttons, including winter mode (marked with a snowflake mark or named as ECT SNOW), economy mode, or sports mode. But some automatics also have a mysterious “Shift Lock Release” button.

The purpose of various buttons mentioned above is more or less clear on an intuitive level. For instance, it is quite simple to guess the meaning of the button ECT SNOW/*- it actuates winter mode, i.e. the car starts moving from 2-nd gear to prevent slippages on snow or ice. When this mode is actuated, the behavior of the car gives a clear hint at its purpose. But when we are talking about a Shift Lock button, it is not that simple. The point is that nothing changes when this button is pressed, or rather the driver notices no changes in the transmission operation.

As a rule, the Shift Lock button is placed close to the gear lever (commonly next to P gear). When you this button is pressed the transmission continues normal operation, the RPM rate of the engine doesn’t change, gears shift smoothly, and there won’t be any special icons highlighted on the dashboard. So what’s that? A trick from manufacturers? No, some drivers may not even need to use this button for years, but in some situations it can be extremely helpful.

Why actually automatics are equipped with a Shift Lock Release button?

First of all, it should be noted that unlike Tiptronic or Overdrive, Shift Lock is not some special driving mode and does not affect the gearbox operation. In fact, this button allows you to forcefully remove the lock when the transmission is in P mode and to put the gearbox in some other gear, if the car engine is turned off.

Owners of automatic cars should know well that the shaft lock inside that transmission becomes actuated, when the selector is put in P gear. After that, it is impossible to move the lever without pressing the brake pedal or without inserting the key into the ignition switch (different brands implement this algorithm in various manners).

Learn how to use shift lock release for double parking

That’s where Shift Lock can come in handy, as this button allows unlocking the transmission gear shaft and put the lever in N position, when the engine does not start or the gearbox fails, and it is needed to start towing the car. Thus, it may be concluded that the Shift Lock button is intended for unlocking the transmission (out in P position), if your car happens to be involved in a road accident or the transmission unit gets out of order.

This button can also be useful during maintenance services of automatic cars. If the gear shifting mechanism gets out of order, technicians from repair shops can shift gears with the use of Shift Lock.

In some cars, the Shift Lock technology is implemented not by means of a special button, but by a key hole also located near the gear lever. In fact, this key hole is actually an analog of a button. In this case, to unlock the transmission, it is needed to insert the ignition key in the key hole mentioned above.

Learn how to use Shift Lock mechanism properly

Summary

Even taking into account technical superiority and reliability of modern automatic cars, it is impossible to rule out the possibility of road accidents, transmission malfunctions, or gear lever locking. In these cases, it may be necessary to unlock the lever and the Shift Lock button (or its key-hole analog) solves this problem. It is also important to remember that it is recommended to keep the brake pedal pressed, when you shift from P to N with the use of Shift Lock. It will help to exclude any uncontrolled movement of the vehicle. Even if the car stands on a flat surface without any inclinations, for safety reasons, it is better to press the brake pedal when using the Shift Lock button.

In conclusion, it should be noted that before intensive usage of a new automatic car, it is desired to become familiar with all functions, buttons (Shift Lock in particular) and modes of the gearbox (described in detail in the manual) to enjoy its benefits to the fullest.

What Happens to Conventional Automatic Transmissions If They are not Warmed Up Properly in Winter Time

Tue, 03 Dec 2019 00:00:00 -0700

What Happens to Conventional Automatic Transmissions If They are not Warmed Up Properly in Winter Time

With winter approaching, car owners perform necessary measures to prepare their cars for cold weather and icy roads. However, some inexperienced owners of cars equipped with automatic transmissions frequently do not know how cold weather may affect transmission units and frequently disregard such a simple procedure as a transmission warm-up. In this article, we will consider how ignoring of the automatic transmission warm-up may affect your vehicle.

Old automatics from the '80s.

It is still possible to see on the road old cars that come with automatic transmissions with a hydraulic-vacuum control and a standard mechanical pressure, which can be supplemented by a vacuum valve. Shift times in such transmissions are regulated by means of the selection of sections and by energy of the accumulators. Such transmissions are non-adaptive, but thanks to their design simplicity and robustness they may have quite a decent operational lifetime. For instance, repair specialists still encounter ZF 4HP18 automatics (installed on Audi 100/A6 C4), which are in good operating condition even after 300 thousand kilometers of mileage.

ZF 4HP18

But still, these low maintenance transmissions may shift harshly or hang on one gear without a proper warm-up in winter. The thing is that in cold weather the transmission fluid (ATF) becomes thicker. In addition to the inability of mechanical regulators to adapt to changes in ATF’s property, these old automatics are also affected by overall wear processes. Much depends on stiffness of the springs and cross-sections of nozzles, which deteriorate with time.

Designs of old automatic transmissions (a lot of GM units) include vane-type pumps, therefore there is a risk to damage an oil pump during the throttle depressing cycle with a “cold” transmission. There is a possibility of seals and gaskets damage, plus the load on internal components of the torque converter, its seal and the oil pump will increase, thereby reducing the resource of these components.

Old electronically-controlled automatics

Early electronically-controlled automatic transmissions using only on/off solenoids and a mechanical drive of the selector are in repairs more frequently. These are Aisin AW50-40, early VW 01M, Jatco RE4F02A and others.

VW 01M

In general, such transmissions are more reliable than vacuum-hydraulic units – they are also quite maintenance-friendly, but they also have temperature sensors and simply designed valve bodies. The presence of the latter component is beneficial: for instance, you can manage without resorting to the torque converter lock-up to improve the transmission warm-up and not to overload it with the engine RPM until it is ready to handle high loads.

Jatco RE4F02A

Since gear shifting times for these transmissions also depend on hydro-mechanical mechanisms, they are also extremely sensitive to the ATF viscosity. Thus, if drivers do not warm up a car with such transmission, they may have to deal with harsh shifting.

Overall, these transmissions may be exposed to the same issues as classic automatics, if they are not warmed up properly before driving in cold weather. Moreover, electronically-controlled automatic transmissions are also notable for their strength reserve, as this generation of automatics can operate with mineral oils, which have a huge range of viscosity fluctuation.

Transmissions with one linear solenoid

The electric valve for adjusting the operating pressure, also known as the linear solenoid, made it possible to significantly improve the operation capacity of automatics when the viscosity of ATF changes – these solenoids first appeared on some relatively old 4-speed transmission models (such as GM 4L30E, 4L60 / 4L60E / 4L85E and Aisin Warner AW60-40LE), which remained in service after the mid-90s.

GM 4L60E

AW60-40LE

These solenoids found application in all 5-speed automatics, except, perhaps, the very first 5-speed transmission Mercedes 722.5. Its successor (722.6) had two linear solenoids: one was responsible for working pressure, while the 2-nd ensured the torque converter lock-up.

722.6

This new feature allowed improving the transmission’s capacity to operate with hot oil as well as the pressure control with too thick oil. For this generation of automatic transmissions, manufacturers developed different types of ATF, which are originally less thick, thereby improving the transmission capacity to operate without any warm-up and maintain working capacity in case of overheating. The appearance of linear solenoids in automatic transmissions brought a lot of benefits: they allow reduced pressure during normal gear shifting, keep the pressure up in sports mode, compensate oil pressure losses, etc.

It is also interesting to mention that the presence of a linear solenoid gave rise to the myth of lifetime transmission fluid – marketing specialists decided that if the transmission is well adjusted to different ATF viscosities, drivers should not trouble themselves with ATF maintenance procedures. But for some reason, marketing experts did not take into account that ATF viscosity is not the only parameter that changes during the transmission operation. They totally forgot about wear debris and other impurities. The thing is that thick and dirty ATF has a negative impact on the linear solenoid in the first place. Over time, its operating range decreases and the transmission becomes extremely dependent on the parameters of ATF pressure and its viscosity, resulting in serious damages in a short time.

If such automatic transmissions are fully operational, their valve bodies and oil pumps are not worn out, then they can operate properly even without any warm-ups in cold weather. However, it doesn’t mean that this procedure should be totally disregarded, as loads on the torque converter blades and the oil pump are still quite high. But if the transmission is worn out, ATF hasn’t been changed for quite a while, and the linear solenoid is old, then the transmission may not operate at all without a warm-up, or operate with jolts and slippages, damaging the mechanical part and hydraulics.

“Cold” starts significantly overload linear solenoids and contaminate them, as the oil filter poorly cleans cold ATF. Protecting automatic transmission, the linear solenoid is the 1-st to get out of order.

Modern automatic transmissions

The next changes in design of automatic transmissions are associated with the introduction of better regulation of the friction clutches engagement speed. For this purpose, manufacturers dropped simple on/off solenoids and started using more complex and costly solenoids. We’ve already mentioned linear solenoids above, which became widely used in Aisin transmissions. Moreover, we should also mention VFS (Variable Force Solenoid) solenoids - controlled solenoids with a spring-loaded valve to stabilize pressure. These solenoids are more complex and wear-prone, and they are frequently used in ZF and GM transmissions.

VFS (Variable Force Solenoid) solenoid

“Complex” solenoids found application in some 5-speed transmissions (such as Aisin AW55-50), but these solenoids are more common to 6-speed automatic transmissions. The use of new technologies is accompanied by the control unit repositioning from the outside to the inside of the transmission, as the operation accuracy of the solenoids is highly dependent on quality and length of the wiring (the shorter it is, the better). This type of design is implemented in ZF 6HP19-6HP28, GM / Ford 6T30 / 6T35 / 6T40 / 6T45, Mercedes-Benz 722.9 and other modern transmission models.

ZF 6HP19

The adaptability of such automatic transmissions has been increased even more. It allowed to integrate a torque converter lock-up in 1-st or 2-nd gear, which in turn reduces excessive oil heating and fuel consumption. But at the same time, the use of more complex solenoids causes their faster wear-out when compared to simple on/off solenoids. This wear process lies not only in damage of winding or complete sticking of the valve, but also in gradual change of the transmission performance capacity over time. If it is a new transmission, it can easily handle too thick or too thin oil.

GM 6T40

In cold weather, the torque converter and the oil pump of modern transmissions may be exposed to increased loads, but they do not have any significant effect because of improved operating range of the transmissions. These transmissions became more protected. Internal components of such transmissions are also well-protected from excessive oil pressures. But it works this way only until the solenoids get worn.

Mercedes 722.9

When contaminated ATF and driving with the “cold” transmission finally damage the linear solenoid, the cold oil starts affecting the whole transmission system, which is quite sensitive to pressure jumps (which frequently occur when linear solenoids start wedging. In general, if the “vicious cycle” is launched, then modern automatics will get out of order faster than classic transmission models.

All in all, the adaptability of modern automatic transmissions may play a dirty trick on car owners: for long periods of time some issues in advanced automatics may not manifest themselves in particular symptoms. But when more serious symptoms finally manifest themselves, it is usually too late to try solving the problem by simple ATF change: it will be necessary to perform costly repair with replacement of at least several solenoids, seals, and gaskets. In older transmissions, it is easier to notice serious problems in the early stages and they are more durable at low temperatures.

Typical Automatic Transmission Problems: Symptoms and Reasons

Sat, 30 Nov 2019 00:00:00 -0700

Top 5 typical symptoms of a failing automatic transmission

1. Slipping gears

Slipping transmission means that the engine is revving higher than it should when you are driving and so lacking power. Other warning signs to note would be:

Difficulty in shifting the transmission into the next gears
Unusually high RPM (rotation per minute) values
Strange sliding sounds when between gears
A burning smell of the ATF
A check engine light

All these symptoms above can mean an ill running engine or worn clutches. Usually, replacing clutches, bands and other internal parts will need an impact from a professional transmission technician.

If you aim at fixing slipping gears in your transmission by yourself, make sure you are not targeting ‘wrong’ parts and check on the solutions given above in this list. Also, remember to verify your transmission in the transmission finder.

2. No shifting or Hard shifting

There may be a range of internal parts invoking this issue. Insufficient pressure can be due to pistons, solenoids and fluid pump failures. Also, this might be an issue with shift cables or the clutch linkage as well as with the car's computer system. Sometimes, computer system failure is fixed by rebooting. Reconnect it after disconnection for 20-30 minutes. However, in the majority of cases we recommend having a transmission professional check it out for you.

Check if you have parked on a hill as this can cause your vehicle to get out of ‘Park’ with difficulty due to extreme pressure on the park mechanism. This is usually not related to transmission problems.

3. Shuddering

The symptom of a shuddering transmission is usually due to wear or pressure issues with bands or clutches when they lose their holding capacities. In fact, this can also be due to ATF problems, ill running engine, valve body issues, transmission computer giving out improper signals and more. Have a trusted technician analyze this issue and all the associated systems.

4. Delays

Spotting delays in shifting is quite easily. It is possible to merely observe the time between consecutive shifts. Some most frequent transmission problems that these delays can mean:

Transmission solenoid issues
Problems with the engine
Low level of ATF or its dirty condition
Worn out transmission filter
Clutch or torque converter issues
Transmission cooler failure

5. Noises in neutral gear

It is fairly easy to spot them as you can barely miss odd sounds emitted from the transmission only while you're in neutral and not moving. These are straightforward indicators that your transmission or engine could be the culprit. The common issues include the following:

Worn-out bearings
Loose internal components
Loose exhaustion system
Problems with the engine

All of these symptoms require a thorough inspection of your vehicle’s systems. You can do some of these checks at your garage. These typically point to where you should do a more thorough inspection with transmission professionals’ assistance.

The Torque-Drive Transmission: Chevy’s Manually-Shifted Automatic

Mon, 18 Nov 2019 00:00:00 -0700

The Torque-Drive Transmission: Chevy’s Manually-Shifted Automatic

Car manufacturers have always been looking for ways to make their cars more cost-efficient and customer-friendly, developing less expensive car components (engine, gearbox, etc.) in hope to increase the take rate of their products. The history of auto industry knows a lot of cases when such approach turned out to be a complete flop. In this article, we go back to 1968 when Chevrolet released its semi-automatic transmission named “Torque-Drive” . In fact, this unit was developed on the basis of an upgraded Powerglide transmission and could only be operated by a driver.

Torque-Drive transmission

The engineering structure of this unit included a torque converter and a 2-speed planetary gear set. It was intended for all Camaro and Chevy II models. The primary mission of Chevrolet engineers was to create a gear shifting solution that would become a less expensive alternative to the Powerglide unit. In fact, the Torque-Drive unit was still a Powerglide without the valve body and shift solenoids. The lack of these elements eliminated the automatic gear shifting capacity. But at the same time, this design allowed engineers to reduce production expenses of the unit and its selling price – only $68.65, in 1968.

It should be pointed out that the gear-change lever in cars that came with the Torque-Drive unit was installed on the steering column with 5 shifting positions (P, R, N, Hi, and 1-st).

The driver started moving at 1st gear, and when it was necessary to switch gear, he moved the lever to Hi gear. If the driver didn’t want to trouble himself with a tricky process of gear shifting, it was possible to drive only in Hi gear. Finally, it was recommended that 1-st gear should only be engaged at speeds up to 20 mph, while shifting from Hi to 1st gear at speeds above 55 mph may lead to the gearbox damage.

For better or worse, the Torque-Drive unit didn’t last long. It is said that Chevrolet manufactured approximately 14,000 controversial transmission units, which then got lost as a passing reference in the history of the auto industry.

Brake Band in Automatic Transmission: Purpose, Principle of Operation and Special Aspects of Its Adjustment

Thu, 14 Nov 2019 00:00:00 -0700

Brake Band in Automatic Transmission: Purpose, Principle of Operation and Special Aspects of Its Adjustment

Automatic transmissions are technically complex units, as they consist of numerous elements such as planetary mechanism, torque converter, valve body, friction elements, brake band, etc. Over time, these key car components become even more sophisticated, since car manufacturers put in much effort to make their new models more reliable and comfortable. In particular, they try to eliminate one of the most common transmission issues – jerks during gear shifting. That’s where an automatic transmission brake band comes into play. In this article, we will consider the main purpose of the transmission brake band, its design peculiarities, place of installation, and why it is necessary to adjust this element.

The brake band is included in the planetary gear control system together with friction discs, one-way clutch, etc. The automatic transmission brake band is necessary to block planetary gear elements for a short time. The composition of bands includes metal lined with organic friction material. This element locks the ring or sun gear or allows them spinning. Its operation is controlled by a hydraulic unit.

The band is installed on the gearbox casing: one end of the band is connected to the casing itself, while its 2-nd end is linked up with a running piston of the servo unit. Changing of the band state has a direct impact on the operation of the drum half of the clutch pack with the planet gear of the other half of the clutch pack. That’s how an automatics shift gears in compliance with the RPM rate.

The principle of the planetary mechanism holding/locking is similar to the principle of operation of the brake shoes. All automatic units are driven by ATF. When ATF reaches the servo mechanism, its piston starts moving under the pressure created by this fluid. As a result, the brake band tightens and locks elements of the planetary mechanism for a certain period of time. Once that time has elapsed, the planetary gear set gets unlocked and ATF shuts down the servo mechanism. As the fluid pressure equalizes, the band weakens, a special back-moving spring starts affecting the piston, and it returns to the initial position. The band returns to its free state.

Learn more about transmission brake bands and how they differ from clutches

A band serves as a reaction mechanism, with the concept of operation similar to multiple clutch discs and one-way clutches. But there is one key distinction. A transmission band is strictly a stopping and holding component, while clutches are intended for holding and running parts of the planetary gear set.

Peculiarities of design

Commonly, a brake band is made of a flexible metal alloy (namely, numerous strips of this alloy). This material is durable enough to withstand extreme abrasion and tear loads. To make the band more durable and reliable, engineers apply a friction coating to the interior part of the band.

Bands can be single or double wrapped. Double wrapped bands are more efficient than their single wrapped analogs. With time, bands wear out, leading to appearance of a gap between the band and the drum. In result, a gearbox will start slipping.

Over time, metal strips and friction coating of the band start wearing out, thus it is necessary to replace the band at certain intervals. It is recommended to buy a new band complete with adjusting screws (bolts). These screws can be installed both on the inside and outside part of the gearbox depending on its design peculiarities. Both types of positioning have their own advantages:

In case of internal positioning, the screw head is not subjected to pollution and corrosion.
External arrangement allows adjusting the band without dismantling of the housing. Moreover, such positioning of the bolts is more convenient and less costly, as the band adjustment in this case can be performed independently, without visiting a repair shop.

It is necessary to check and adjust the band tension not only after its replacement, but also after any transmission-related repair and maintenance services, including adding and changing of ATF. If the transmission starts kicking or jerking, the first point that you should check is the band state.

The most common issues of the planetary gear locking system (transmission brake band) and their consequences are the following:

Damage or wear of the friction layer on the brake band, resulting in incomplete locking of the planetary mechanism. As a result, during the process of gear shifting drivers can experience jolts or hear scratching noise in the automatic transmission;
Breaking or other issues related to the piston cup of the servo mechanism. In this case, the brake band is also unable to block the planetary gear set. Each gear ratio change is accompanied by jerks in the automatic transmission;
Damage of the piston rod in the servo mechanism. In case of mechanical damage, the piston get destroyed and its fragments/debris are transmitted to different transmission areas via ATF. If this problem is not addressed timely, then the transmission will get out of order;
Wear or damage of the spring, contamination of the servo mechanism. In this case, the brake band will “wedge” moving parts of the transmission. As a result, the car won’t be able to start moving or R gear won’t work.

Band adjustment

To ensure normal operation of the transmission brake band, it is necessary to regularly monitor the clearance between the brake drum and the band. It is performed with the help of adjusting screw (or hairpin with a lock nut).

Adjusting screw and hairpin with a lock nut

If the adjustment procedure is performed by means of a hairpin, then it should be done with the help of a torque wrench. It may be necessary to remove the transmission pan (if the adjustment screw is located inside the gearbox housing).

Special instrument for a transmission brake band adjustment

It is interesting to point out that in some automatics brake bands are adjusted with the help of special rods of various lengths. In this case, the adjustment procedure is performed by dismantling of the unit and installation of the rod of the required length. Sets of rods are manufactured by manufacturers of such transmissions. It is desirable to perform some kind of preventative diagnostics by checking the band condition during ATF change. It is important not to stretch the band too much, as it can speed up the wear-out.

That’s how a transmission brake band is adjusted

It is also possible to adjust the brake band without a torque wrench. In this case, the adjustment procedure is performed as follows:

The car should be stopped on a slope;
To avoid uncontrolled movement of the car, it is necessary to put it on the hand brake, while putting a slop block (or a brick) under the wheel;
Release the hand brake and check whether the slop block holds the car unmoved;
Engage the hand brake again, while repositioning the slop block a few centimeters from the wheel;
Loosen the lock nut to simplify the process of tightening the adjustment screw;
Tighten the adjustment screw until a light stop;
Release the hand brake, gradually loosening the adjustment screw of the brake band and wait until the car starts rolling;
Tighten the adjustment screw by 2-3 turns (the number of turns is determined experimentally for a specific car until there won’t be any jolts during gear shifting).

Brake band adjustment in a legendary Ford T

Transmission brake band replacement

To install a new brake band, it is recommended to follow the instructions below:

First of all, the car must be jacked;
Remove the wheel to gain access to the transmission unit;
Dismantle accumulator battery and air filter;
Put the jack under the transmission unit and lift it up;
Remove the transmission mount;
Remove the bolts that hold the back cover;
After removing the cover, it is possible to replace the brake band;
Remove the old band and replace it with a new one;
Close the back cover (do not forget to use the sealing compound), and reinstall all the dismantled components;
Check the brake band state;
Finally, check the car behavior on the road. Regardless of the acceleration rate, there should be no jolts during the process of gear shifting.

After removing the old band, it is recommended to evaluate the nature of its wear. If the band gets out of order after a short time, it is necessary to find the source of the issue. Frequently, the problem lies in improper operation of the servo mechanism. As a result, the planetary gear set wedges and wears the band.

GM TH700R4 4L60 automatic transmission brake band

It follows from the above that the brake band plays a significant role in ensuring smooth gear shifting in automatic transmissions. Thus, the owners of automatic cars should remember that the problem of jolts in transmissions can be frequently solved by adjustment of the band tension. Adjustment and replacement of the brake band can be performed independently by the driver. Regular checks of the transmission band tension helps to prevent jolts, loss of driving comfort, and excessive mechanical wear of the transmission unit.

Mitsubishi Super Shift Transmission

Wed, 06 Nov 2019 00:00:00 -0700

Mitsubishi Super Shift Transmission

Nowadays, the automotive engineers have access to a wide range of incredible technologies, therefore each year car manufacturers amaze us with new models packed full of sophisticated features. But 30-40 years ago, the auto industry, despite limited diversity of technical solutions at that time, also was able to deliver cars with wondrous design peculiarities, For instance, everyone who had a chance to get behind the wheel of Mitsubishi Mirage (1-st Gen) could have been amazed to see 2 transmission control levers instead of one. In this article, we will take a closer look at the famous (in its days) gear shifting technology designed by Mitsubishi.

The Super Shift transmission, also known as Twin-Stick, is a manual gear shifting solution designed by Mitsubishi in the late ‘70s. This solution found application on several Mitsubishi models, which were produced mostly in the ‘80s. This unit is notable for some design peculiarities: this 2WD unit has 8 forward gears. Moreover, the design of this manual is complemented by the overdrive unit, unusual feature for a stock car of this type. This gearbox was designed on the basis of a standard 4-speed manual unit to be applied on the 1-st Gen Mirage model, the carmaker’s 1-st FWD vehicle.

Super Shift transmission used in the Mitsubishi Chariot

Mitsubishi engineers wanted to lower the center of gravity of the car as much as possible, thus they decided to position the gearbox below the level of the engine crankshaft. In addition, it was necessary to force the main gear to rotate in the right direction, as it was impossible with the existing layout. Thus, Mitsubishi engineers came up with the idea to apply an additional idler/lay shaft. This solution forced the axle drive gear to rotate in the right direction, but also to place lower all heavy components (shafts with clutches and the main gear). It was then realized that the idler/lay shaft could be implemented as a separate 2-speed gearbox, which would be actuated by a 2-nd shift lever placed near the main gear stick inside the cabin.

A standard 4-speed mechanism was complemented by a 2-speed “high-low” selector, which, in turn, efficiently split each of the four gears in two. As a result, the Twin-Stick unit had 8 forward gears and 2 rev gears. In fact, this technology was not something new for the automotive industry, as the same mechanism had been widely used in heavy-duty applications before the Mitsubishi solution.

Take a look inside the Super Shift transmission

In passenger cars equipped with this gearbox, the additional lever was marked as 'Power' for the lower range, and 'Economy' for the higher range. In some cars the 2-nd stick was as marked with a star icon for the lower range and 'E' (economy) for the higher range. When driving on the road, the engaged mode was highlighted on the dashboard.

In practice, it was almost impossible to use all forward gears sequentially, as the shifting process would require too many movements with two levers, therefore owners of cars equipped with this gear shifting technology used the low 'Power' mode most of the time to ensure better dynamics, while only shifting to the E mode when driving with constant speeds along the highway.

Similar gear shifting technology implemented in Subaru Forester

It is interesting to note that this gear shifting concept is implemented in some Subaru cars. This remarkable technology became a part of history in 1990, when Mitsubishi decided to shut manufacturing of the Tredia and Cordia models.

Looking Inside EAG’s 2020 Supra Transmission Swap Project (Part 2)

Mon, 04 Nov 2019 00:00:00 -0700

Looking Inside EAG’s 2020 Supra Transmission Swap Project (Part 2)

It has been some time since the tuning company European Auto Group (EAG) came up with the idea to astonish the automotive world by delivering the first in the world manual 2020 Toyota Supra. The thing is that the factory-built Supra comes with the automatic transmission only, disappointing admirers of the classic Supra design with a gear stick. But it seems like a manual 2020 Supra is going to happen after all, as the EAG team has finally integrated a 6-speed manual transmission in the Supra design. In this article, we’ll take a closer look at all stages of the transmission swap process with the help of videos from EAG’s youtube channel. Here is the link for Part 1.

It’s nice to know that Go4trans team has also contributed to this promising project, as we’ve been an intermediary between Art Bartosik, the head of EAG, and our UK partners from Sussex Auto Parts and Hydra-Test, who by combined efforts managed to supply a long-awaited transmission unit (gs6-45dz) to the EAG facility in Texas.

Art is happy to see a manual transmission for his project

As soon as Art and his colleagues received a delivery package and made sure that the starter was located on the bottom (that’s actually one of the reasons why EAG had to get the transmission assembled in Europe), Art said that it would certainly work out.

In the 1-st video, the EAG team had to take the Supra’s interior apart and match up all the parts. But before that Art connected the scanner to the car and checked it for error codes to deal with all possible issues before tearing the car apart and avoid possible issues during the actual transmission swap. After this preventative measure, they put the car on the lift and started tearing it apart. When it came to pulling out the transmission unit, ATF suddenly started pouring on the ground, but guys put the bucket under it. When they finally removed the gear shifting unit from Supra, Art compared it to the recently received manual unit and found out that the manual ZF transmission was a bit shorter than the automatic.

Manual vs. Automatic

To deal with this issue, Art decided to make spacers and longer bolts to compensate the difference. It was also decided to use the mounting bracket from the automatic. The next practical step was to remove the torque converter and to line up the flywheel to mount the gearbox and see how it fitted. It helped EAG to make necessary measurements and produce proper spacers.

In the 2-nd video, it became possible for the EAG team to start mounting some of the shift linkages, as they finally received the shifter assembly from BMW. Art had to cut out the hole in the panel to place the shifter boot in the right place, center the linkage, and see how far it should be modified to match up to the cabin. Art was quote nervous during this delicate procedure, as he had to be very precise in order not to damage anything. Fortunately, it worked out pretty well. After the shift linkages were installed, they put the car off the lift to see if it was necessary to make any adjustments. Fortunately, there were no problems as Art was going through all the gears.

To modify the drive shaft, which turned out to be a bit short in the manual transmission, EAG specialists took the guibo disc from the automatic transmission and adjusted it to the manual unit to make necessary measurements. As a result, EAG extended the driveshaft about 3 inches to make it fit. And it actually looks like an original OEM part. They test fitted the part and it looked promising.

Art removes the guibo disc from the automatic transmission

In the next video, Art showed an extended transmission mount used in a 335 BMW model, which helped to solve the problem with the length differences and fitted in perfectly well for the manual Supra.

Then it was the time to the get inside the Supra’s interior and to remove the brake pedal assembly in order to test fit the clutch box assembly. However, after removing the brake pedal, they found out that there was no mounting point for the clutch pedal, thus the EAG team came up with the idea to use a pedal box from some BMW model that had to do the job. After doing some modifications and adjustments tricks, the 2020 Supra got the clutch pedal mounted.

Check out the final episode of the 2020 Supra transmission swap project

Before performing a final installation of the transmission unit and all related parts, EAG tech specialists test fitted all parts and everything seemed OK, but later it turned out that the flywheel didn’t fit in. To fix the issue Art had to perform some measurements and to do some adjustments to the dowel pin and the hole of the flywheel. When the flywheel finally found its place into the mounting location, Art and his colleagues proceeded with the clutch assembly installation. Finally, it was necessary to mount the transmission and to try it in action. Fortunately, tremendous efforts of the EAG team were not in vain and they’ve got the 2020 manual Toyota Supra running. This unique car has already reached SEMA 2019.

Manual Supra at the SEMA Show

Now owners of a factory-built 2020 Toyota Supra equipped can get a transmission swap service from European Auto Group. But should certainly hurry up with an order, as EAG plans to perform only 16 transmission conversions in 2020, each costing a total of $12,000 with a $6,000 upfront deposit.

As for the future, it seems like the 2020Toyota Supra won’t be the last in the list of EAG transmission swap projects, as the company considers installing a gear stick in the Chevrolet C8 Corvette.

How Gear Ratios Define the “Character” of Your Car

Thu, 31 Oct 2019 00:00:00 -0700

How Gear Ratios Define the “Character” of Your Car

Having a clear understanding of the term gear ratio and the impact of this parameter on speed, acceleration dynamics and fuel efficiency allows you to choose the optimal driving mode. This parameter is extremely important for any car, regardless of its price and year of production. Frequently, unexperienced auto enthusiasts pay little attention to gear ratios when buying a new or used car, but a competent analysis of technical car parameters (including gear ratios) turns out to be a key to the successful car choice. In this article, we will consider how gear ratios can affect performance potential of a car.

Highest gear

First of all, when looking for a car, it is recommended to pay attention to the gear ratio of the highest gear. This relevant parameter specifies the maximum RPM rate at cruising speed, which has a direct impact on the fuel economy and noise intensity. To put it shortly, a taller gear ratio ensures lower fuel consumption and less noisy operation, but at the same time, it will be necessary to downshift to achieve better acceleration dynamics (for example, when it is necessary to overtake other cars). The optimal RPM rate when driving at cruising speeds is approximately 1600-2000 for diesel-powered and 2000-2500 RPM for petrol-driven cars.

For instance, the transmission unit in the GT86 has 6 gears with quite close gear ratios, to accelerate up to 100 km/h (70 mph) the engine has to operate at 3000 RPM. This is the reason for the significant amount of harmful emissions equal to 181 g / km. This is too much for a car equipped with a two-liter engine producing 200 hp and good aerodynamics. Moreover, such a setup will lead to increased noise intensity during the operation (especially in case with significant mileage), and it will be a significant drawback if you decide to sell this car. This can hardly occur in cars that come with automatic transmissions, which have taller gear ratios, but many admirers of classic sports cars are extremely wary of automatic transmissions in performance cars.

It should be remembered that the more powerful engine is installed in your car, the lesser RPM rate is produced by the engine at cruise speed, and the less noise you hear when driving. For instance, the Golf Mk6 1.6 TDI equipped with a 5-speed manual transmission cruises at 2300 RPM, while for more powerful SEAT Ateca 2.0 TDI that comes with a 7-speed DCT transmission this parameter is approximately 1700 RPM. That is why in some modes of operation cars with more powerful 6-cylider engines consume a bit more fuel than cars with 4-cylinder engines.

Learn more about how car gearing works

“Short” gears, determining the need for frequent shifts, are considered to be the key to aggressive driving. This means that the more intense the speed-up, the lower the maximum speed that a car can pick up at one gear. “Short” gears improve acceleration characteristics and make the car more performance-oriented, but at the same time badly affect top speed and fuel economy (it can be solved by using a transmission with more gears).

However, there are some exceptions to this rule, as the most powerful cars do not need low gear ratios in several first gears – their traction is quite enough to ensure intensive acceleration and not to bother the driver with the necessity of frequent gear changes. For instance, the Dodge Challenger Hellcat can reach the speed of 101.3 km/h (63 mph) in 1-st gear without any additional shifting. But the most vivid instance of non-aggressive gearing is the Koenigsegg Regera, which reaches 402 km/h (250 mph) in 1-st gear. It is not about setting a speed record, but rather a reasonable engineering approach and bearing in mind the engine potential and adhesion to the road surface. In other words, if such performance car is equipped with a transmission with shorter gears, then there will not be any benefits in terms of dynamics, as the process of gear shifting will require more time; excessive traction and torque will simply lead to slipping of the wheels.

Koenigsegg Regera

It is also worth noting that with a large number of gears, engineers will have to do a lot of work to keep the engine operating with the RPM rate, allowing achieving maximum power and torque, when shifting gears. At the same time, it will significantly complicate the design. It has long been proven the acceleration up to 300 km/h in sports cars is fully ensured by the thrust of powerful engines –lower gear ratios are simply unnecessary.

When it comes to civil vehicles (road cars) intended for everyday use, first gears in transmissions for these cars are quite short (with low gear ratios), allowing the car equipped with less powerful engine to move confidently on loose surfaces and to accelerate under heavy loads. It is also important to consider such parameters as gross vehicle weight (GVW) and its running weight, as the difference between these values determines the actual vehicle capacity, or load capacity, and the higher the capacity, the shorter the first gears should be.

Close and Wide Gear Ratios

The gap between gear ratios also plays an important role in determining the “character” of any vehicle. Closer ratios ensure the maximum acceleration that can be achieved. In addition, if the fuel efficiency is considered to be a priority, close gear ratios allow keeping the RPM rate in an optimal zone, facilitating to enhancement of the engine service life. At the same time, close gear ratio has one significant drawback, as it makes the highest gear too short or makes the 1-st gear too long, and both variants are undesirable. There are two solutions for this problem: either increase the number of gears (at the same time raising the cost of design) or use wider ratio.

The choice of the solution is determined by the type of car being designed. For performance-oriented cars engineers usually resort to closer gear ratios implemented in the gearbox design. If the car comes with the engine having wider powerbands, then closer gear ratios are simply unnecessary. In such cases, engineers go with wider ratios.

At the same time, it should be noted that closer gear ratios do not always ensure better performance characteristics. For instance, if we get away from the automotive world and consider a sports bicycle, then will see that, as a rule, it has 8 gears with close gear ratios, thereby allowing the most rational use of the bicycle’s operating capacity. However, when using such design solution, it will be necessary to shift gears very intensively in the interval from 1-st to 5-th gear to ensure maximum acceleration. The same idea applies to cars. The necessity to shift gears very frequently, as a rule, makes the engine to operate in non-optimal mode, especially if an inexperienced driver is behind the wheel.

All these shortcomings are eliminated in so called stepless types of transmissions (better known as CVTs), which smoothly change gear ratios, depending on the selected driving mode. But CVTs also have some soft spots, therefore it can be said that so far automotive engineers haven’t managed to design an ideal mechanism capable of transmitting high amounts of torque and quickly adjusting to accelerating dynamics of sports models.

Final drive change

If you want to make the most of your car’s dynamics characteristics, the most efficient solution here is to change a final-drive. This procedure implies installing a new diff with an alternative internal gear ratio. A lower number presupposes longer gears and a higher number means shorter gears. It doesn’t mean that you’ll be able to determine how close or wide the gear ratios are, but it will allow you to change all your gears by the same amount that is best suited for you.

But this method cannot be considered as a panacea for all woes, as it is possible to change the abovementioned parameter only in a very short range of values, otherwise it will do more harm than good. It should be remembered that if you decide to do this trick, it will be necessary to adjust the speedometer, otherwise its values won’t show a real car speed because of the new ratio.

Learn more about final drive and its role in your car

This type of tuning can be implemented without too much difficulty in FWD and RWD cars, but in some FWD and AWD cars this procedure is simply impossible. Many cars come with gearboxes, which have a built-in differential, thereby making it quite problematic for DIY- car owners to change the final drive. In addition, some cars (for instance, Audi R8) have different final drive ratios in front and rear drives.

But sadly, more and more manufacturers chose to use integrated units, therefore to improve performance capacity of your car without causing any damages you’ll have to visit a professional tuning shop and pay huge amounts of money.

Remarkable Engineering Idea Implemented in 'Doug Nash 4+3' Manual Transmission

Sun, 27 Oct 2019 00:00:00 -0700

Remarkable Engineering Idea Implemented in 'Doug Nash 4+3' Manual Transmission

Each year, brainy automotive engineers come up with more and more technically-advanced transmission solutions, which amaze car enthusiasts with their performance capacities and fuel economy rates. Nowadays, car manufacturers became increasingly alienated from classic manual transmissions and shifted toward highly-demanded automatic and hybrid transmissions. But it should not be assumed that only modern highly-sophisticated units can leave a lasting impression and that there has never been some place for ingenuity in the field of the transmission development. For instance, we can look back to the 1980s when the Chevy Corvette C4 hit the market with a mysterious 'Doug Nash 4+3' manual transmission.

This design concept is an unusual mixture of a 4-speed manual paired with an automatic overdrive. Generally the OD worked in the upper three gears, hence the name "4+3".

That’s how you shift 'Doug Nash 4+3' transmission

The history of this uncommon gear shifting solution dates back to the late 1970’s, when BorgWarner decided to stop manufacturing of 4-speed manuals and sold specifications for the “Super T10” gearbox to a legendary drag racer Doug Nash, who established Equipment & Engineering after he finished his racing career.

'Doug Nash 4+3' manual transmission

Super T10 transmission

Initially, Nash designed engine solutions for American automakers. Subsequently, he produced a series of 4- and 5-speed racing gearboxes, which brought him great glory. These units turned out to be so efficient, he was contacted by Chevrolet to provide his "4+3" solution, which in practice was a modified version of the “Super T10” transmission. Nash sold its uncommon gearbox to GM and eventually this technology found application on the 1984-88 Corvettes. It is claimed that GM used this technology in order to comply with new fuel economy standards. Later, this gearbox was replaced by a 6 speed manual solution to reduce engine rpm.

In practice, the “4+3” gained a somewhat controversial reputation. From the point of view of engineering design, it is an amusing solution, but on the road this transmission became not the best example of quality and robustness. A particular criticism is referred to the overdrive unit, which is sadly remembered for a wide range of issues.

Check out how 4+3 overdrive function operates

According to posts on some internet forums, the Overdrive feature frequently gets out of order. If this happens, the 4+3 transmission becomes a standard manual solution with no overdrive. The key issues were defects with bearing in the carrier assembly, a direct clutch thrust washer breakdown, and a pump sealing issue. This strange manual/automatic solution can hardly be considered as any king of breakthrough in the automotive engineering, but its design uniqueness certainly worth to be noticed as a bright example of old-school engineering.

Peculiarities of Towing a CVT-Equipped Car

Wed, 23 Oct 2019 00:00:00 -0700

Peculiarities of Towing a CVT-Equipped Car

Car manufacturers are constantly improving components and systems integrated in new models. Thanks to new technologies, conventional manual transmissions are gradually forced out from the automotive market by more sophisticated and automatically shifting transmissions, such as continuously variable transmissions (CVTs).

Such transmission solutions are notable not only for design peculiarities and operating principles, but also entail specific rules of operation and some restrictions, which are commonly specified in manuals provided by carmakers. For instance, sometimes it happens that your car can get stuck in the middle and the only way out is to tow it to the nearest repair shop. It can become a real problem for owners of CVT-equipped cars, as not all drivers know how to do it accurately without any harm to a pricy transmission unit. In this article, we will consider the main peculiarities of CVT transmissions and how to tow a CVT-equipped car properly.

Technical peculiarities of CVT transmissions

Nowadays, many automotive brands such as Toyota, Mitsubishi, Subaru, Honda, Nissan are notable for extensive use of CVT s and popularity of this transmission type is caused by a number of reasons.

First of all, design peculiarities of this transmission type ensure gradual and smooth change of gear ratios. In other words, there are no fixed steps (gears) compared to other types of transmission. This special feature guarantees faster accelerations and smooth driving, as there are no power losses during torque transmission from the engine to the drive wheels. Moreover, there are no kicks or jerks when shifting gears.

The popularity of this type of transmission is also motivated by the low cost of manufacture compared to other types of automatic transmissions. However, the main drawback of this transmission lies in relatively small operational resource, especially if CVTs are paired with powerful engines. Due to its design peculiarities, CVTs are unable to operate under high loads. Thus, CVTs are usually coupled with low-power engines.

The main parts of CVT transmissions:

Shafts ( input and output);
Pulleys;
CVT belt/chain;
Valve body (regulates the supply of oil pressure to the pulleys);
CVT pump ( regulates the pulleys operation);
Planetary gear (for reverse driving);
Oil pump, filter, cooling system.

General rules and recommendations on operation and maintenance of CVT transmissions are similar to conventional automatics, but there are also significant differences. In practice, CVTs require more frequent maintenance (oil and filter changes). If for conventional automatics it is necessary to change fluid every 50-60 thousand kilometers, for CVTs this procedure must be performed every 30-40 thousand kilometers. In fact, it is very important to prevent premature wear of the CVT unit. Oil starvation and inadequate fluid levels can lead to rapid wear of the pulley or belt.

In practice, it is necessary to avoid sudden accelerations and slowdowns. With sudden accelerations or extreme braking, some tears can occur on surfaces of the pulleys, resulting in the unit malfunction. It is also important not to allow overheating of the CVT unit. If necessary, additional cooling systems should be installed to prevent serious issues. Drivers also have to keep an eye on the condition of different types of sensors (such as speed, pressure or ABS sensors), as failures of these components can have a negative impact on the CVT operation.

Taking into account the abovementioned peculiarities, let us now proceed to the rules of towing a CVT-equipped car.

How to tow a CVT-equipped car

First of all, it is necessary to remember that in case of non-compliance with certain rules, a CVT transmission can be exposed to serious damages during the towing procedure. Ideally, it is desirable to entirely exclude the towing option and call a tow truck for safe transportation of the vehicle to the nearest repair shop.

If you can neither call a tow car nor continue driving, then it is required to understand and to follow specific towing rules. The main rules for towing a CVT-equipped car are the following:

The engine of the car being towed must be started;
Before starting towing, the gear lever must be shifted to N position;
During towing, the vehicle speed should not exceed 50 km/h;
The towing distance should be as short as possible and not exceed 50 km;

Failure to comply with the abovementioned rules can lead to serious damage of the transmission unit during towing. For example, if a CVT-equipped car is towed with a stalled engine, the CVT oil pump won’t work. When the transmission fluid does not reach important transmission elements, the entire CVT unit will go into abnormal mode. As a result, there may be the following issues: overheating of the input shaft, damage plastic bearings and planetary gear, and failure of the secondary (output shaft). Most operating manuals for CVT-equipped cars include specific instructions on transportation/towing of the vehicles in case of any mechanical damages. Frequently, it is required to ensure a rigid towline between two cars, as the use of flexible ropes can be unacceptable.

There are 3 transportation/towing options:

All wheels stand on a horizontal platform of the tow truck;
A pair of wheels is rigidly attached to the tow truck;
Towing with the help of fastening ropes.

It should be noted that it is possible to tow a trailer behind a CVT-equipped car if the weight of the trailer is within the car’s towing capacity. The only case when you should not use a CVT-equipped car for towing is when it is stated the vehicle Owner’s Manual.

Summary

When dealing with CVTs it is important to remember not only about its advantages (such as enhanced fuel economy, high efficiency, smooth operation) but also about more stringent requirements when it comes to maintenance and compliance with operating rules. If for some technical reasons, a CVT-equipped car gets out of order in the middle of the road, it is better to call a tow truck. If it is not possible, the towing procedure should be performed in accordance with the rules specified in the manual. When towing a CVT-equipped car, it is advised to strictly follow so-called “50x50” rule (the broken car should not be towed for more than 50 km with the speed higher than 50 km/h). Following all the recommendations listed above, it is possible to extend the service life of the transmission unit and other car systems.

Valuable Insights Into Torque Converter Technology From Hughes Performance

Tue, 22 Oct 2019 00:00:00 -0700

Valuable Insights Into Torque Converter Technology From Hughes Performance

The torque converter technology implemented in modern automatic transmissions has gone through decades of modifications and improvements, becoming an extremely efficient solution for smooth transmission of torque from the engine to the drive wheels. There is, however, a lot of misunderstandings related to torque converters, their operation and maintenance peculiarities not only among racers or auto enthusiasts, but also among young and inexperienced technicians. It is not a problem to find some basic info about torque converters on the internet, but there are not so many reliable sources, which provide structured and visual data on this piece of automotive engineering. Fortunately, experts from Hughes Performance came up with a series of educational videos, providing insights into the main features, operation principles, and peculiarities of torque converters with a focus on performance-oriented applications.

The whole series named “Torque Converters 101” includes 7 episodes, in which the host Pete Nichols describes different aspects of automotive torque converters in easy-to-understand terms - from general overview of this technology and its design peculiarities to stall speed characteristic, torque converter ballooning, and its installation details.

Become familiar with basics of torque converter technology

The first 20-minute video explains the torque converter design, its structural components, and some principles of operation. From the pump seal to the cover that bolts to the engine, Pete covers every component that makes up a torque converter and explains its function in a clear and concise way.

Pete Nichols talks about lock-up torque converters

In the 2-nd video you will learn about lock-up torque converters from the OEM perspective and how the lock-up technology contributes to increased fuel efficiency, basically acting like a manual transmission clutch.

Pete Nichols takes a closer look at the various one way clutch variants

If in the first 2 episodes Pete talks about general construction of the torque converter and some basic operating theory, and functioning of the lock-up technology, the 3-rd episode revolves around the topic of one-way stator clutches in torque converters. In this episode you will learn about different variations of this clutch, their functioning peculiarities, and other interesting material.

Pete Nichols talks about different types of stator designs used in performance-oriented torque converters

In the next video, we take a closer look at different types of stator designs used in performance-oriented torque converter builds, materials used in stator design and construction (aluminum, steel, billet aluminum, fabricated steel) as well as their performance capacities and tuning flexibility.

Amazing video about torque converter stall speed

The 5-th episode addresses such an interesting characteristic of torque converters as stall speed. In this video you will learn the correct definition of this mysterious term and its variability in torque converters depending on their field of application. The thing is that stall speed is not a fixed number and there are several factors that contribute to the maximum amount of stall speed that can be achieved with the torque converter: torque output of the engine, the vehicle weight, the gearing in the rear axle, the rear tire diameter (or front tire diameter in case with a front-wheel drive vehicle), and gear ratio. This video will certainly help you to dispel numerous misconceptions surrounding stall speed and torque converter functions.

Pete Nichols explains the issue of torque converter ballooning

The pre-last episode will address the issue of torque converter ballooning. Here you will learn more about this problem in racing torque converters, its possible consequences, and about anti-ballooning properties used in Hughes Performance converters.

In the final episode, Pete Nichols will explain how to properly install a torque converter into an automatic transmission. All in all, thanks to this brilliant series of extremely helpful and informative videos provided by Hughes Performance, all admirers of automotive engineering will be able to fill in their knowledge gaps on the torque converter technology.

Possible Consequences of Using ATF in CVT Transmission

Thu, 10 Oct 2019 00:00:00 -0700

Possible Consequences of Using ATF in CVT Transmission

Nowadays, many car manufacturers include in their lineups models equipped with continuously variable transmissions (CVT). This type of transmission not only significantly differs from standard automatics in terms of design and operation principles, but also ensures extremely smooth shifts and enhanced fuel economy. But CVTs are intended for smooth driving, while sharp accelerations and slowdowns can have a negative impact on transmission components. A crucial role in operability of CVTs is given to specific fluids (CVTF) used only in variable transmissions. These fluids have great lubricating properties and at the same time they prevent the belt from slipping on the pulleys. The achievement of such an objective is possible thanks to the use of unique packs of additives. But sometimes young drivers of CVT-equipped cars often wonder whether it would be safe to use automatic transmissions fluids (ATF) in their CVTs. Let us delve into this question and consider possible consequences of using ATF in CVTs.

Automotive gear shifting units are extremely sensitive devices. Each car model has its own guidelines from the carmaker on which type of fluid your vehicle requires. Some fluids are non-compatible with different gearboxes, as they include sets of additives intended for specific types of gearboxes. Your car transmission must be filled with the appropriate fluid, as stated in your car manual, to operate properly and not to fail before its due time.

While it is feasible to use ATF in manuals without serious harmful consequences for the operability of the unit, putting ATF in a CVT-driven car can actually damage the unit. Fluids for automatics and CVTs not only have different operating qualities, but they also differ in color: ATF fluid is red, while CVTF is commonly green, and it would be better for you not to mix them up.

Check out what can happen with a CVT transmission if it is filled with ATF

If it nevertheless happened, and an absent-minded technician (or a car owner) accidentally filled a CVT unit with ATF, it is highly likely to become a serious problem. ATF is applied for lubrication of automatic gear shifting units and it is not supposed to support the proper functioning of CVTs, which have design and operational peculiarities. CVTs require a special type of fluid which also includes friction modifiers that ensure the accurate friction required for the chain or belt to hold and drive the cones, otherwise these elements would just wear and tear prematurely.

One more opinion on using ATF in CVT transmissions

If you by chance fill a CTV with ATF, the time remained for the unit to work properly depends on the ratio of fluids. In a CVT unit, it is very unlikely that you’ll be able to drain it completely of all CVTF. If you have unintentionally added ATF, your gearbox would then be filled up with a mixture of two absolutely different fluids. Your gearbox will be able to operate properly for some time, but sooner or later your gearbox will get out of order, and in the best case scenario it will be necessary to recondition the unit.

If your CVT-equipped car is filled in with the inept fluid, it is necessary clear the mechanism from unsuitable fluid in order to minimize negative repercussions for the mechanism. If the car has been operating for some time with inappropriate fluid, it is highly likely that the only solution will be the CVT unit replacement.

All in all, a correctly selected fluid for your CVT ensures comfortable driving, service life expansion, and larger intervals between maintenance services. It is also important to remember that different types of CVTs require the use of specific fluids having particular properties. For example, chain-driven CVTs such as Multitronic and Lineartronic require the use of only original fluids, as these types of CVTs operate on a different principle compared to belt-driven units.

Problem of Kicks and Jerks in Automatic Transmissions

Mon, 07 Oct 2019 00:00:00 -0700

Problem of Kicks and Jerks in Automatic Transmissions

Nowadays, cars equipped with automatic transmissions have almost pushed out manually shifted cars off the automotive market. Automatics are popular not only among young drivers, but also among experienced drivers. It is not surprising, as modern automatic transmissions not only significantly simplify the process of driving a vehicle, but they also do not outperform manual analogs in terms of performance characteristics and fuel economy. Automatic transmissions ensure more comfortable driving and safety under the conditions of heavy traffic in urban areas. At the same time, automatic transmissions are quite complex units, which are prone to failures, especially when drivers violate rules of operation. The most common symptom of the automatic transmission malfunction lies in kicks and jerks during the process of gear shifting. In this article, we will explore the main causes of kicks and jerks in automatic transmissions and give some recommendations on how to deal with such issues.

In some cases a driver can continue operating even with jerks, but if this problem stays disregarded for a long time such symptoms can lead to the transmission damage and highly-priced repair. That is why this issue must be addressed at an early stage to avoid unwanted complications. The main task here is to determine the source of kicks and jerks in the automatic transmission.

It can become quite a challenge, as kicks and jerks can manifest themselves at different stages of gear shifting: the issue can manifest itself when moving the shifting lever, during shifting between specific gears, or when you start driving without the transmission warm-up, etc. Proper diagnostics and some indirect signs can help to determine the source of the problem.

Main causes of kicks and jerks in automatic transmissions

In many cases, kicks and jerks in automatic transmissions are caused by issues with the transmission fluid (ATF). This fluid does not only lubricate transmission hard parts, but also serves as a working fluid. The fluid transmits torque from the engine to the wheels and takes part in engagement of required gears by passing via valve body channels under the pressure.

The main reasons for jerks and kicks in the automatic transmission are the following:

ATF is not warmed up;
ATF level is too low or too high;
ATF gets too contaminated and loses its operating qualities;
ATF pressure drops;
Transmission filter is clogged.

If the driver notices some jerks in the transmission when driving, it is necessary to check the ATF level and its condition. Normally, the fluid level must be between HOT and COLD marks on the transmission dipstick (the fluid check must be performed after the transmission warm-up). If the ATF level is too low, it will lead to increased wear of transmission components, fluid pressure shortages, slippage of frictions, and incorrect engagement of gears. If the ATF level is too high, the fluid starts to foam, and the pressure of the foamed fluid is not enough for normal operation of the automatic transmission. Fluid surpluses can be squeezed out through the breather, leading to the transmission greasing from the outside. When the transmission fluid level deviates from the norm, driver can start experiencing jolts when shifting gears.

Slight transmission jerks in many automatic cars, which start moving without the transmission warm-up, can be considered as a norm. Commonly, these jerks disappear when the transmission fluid reaches optimal operating temperatures. To avoid any inconveniences during driving, it is necessary to warm up the engine and the transmission before you take off. During the first 5-10 kilometers it is recommended to avoid rapid accelerations, high RPM rates, usage of kick-down mode or manual gear shifting.

Even if the fluid level is normal, it is also necessary to pay close attention to the general condition of ATF. The fluid must be clean, have normal color, no contaminants (wear debris) or burning smell. If the fluid condition does not comply with operating standards, it is necessary to change ATF as soon as possible.

To put it simply, automatic transmissions must be regularly maintained and ATF change serves as a key maintenance procedure, which determines the service life of the whole transmission. Some auto manufacturers may say in car manuals that ATF is filled for the entire period of the car service life and the transmission unit is maintenance-free. Such recommendations presuppose the operation in ideal conditions, but in reality it is hardly possible. In practice, ATF starts losing its properties after travelling 40-60 thousand kilometers. Therefore, without timely ATF change, the automatic transmission (with the service resource of 250-300 thousand kilometers) will get out of order before reaching 150 thousand kilometers. At the same time, the first symptoms of the upcoming failure commonly manifest themselves in kicks and jerks when reaching the mileage of 100-120 thousand kilometers.

The next transmission component that can cause jerks in the automatic transmission is its filter. The main purpose of this element is to keep dirt and wear debris from ATF. Sooner or later, the filter gets clogged, and its filtering capacity deteriorates. As a result, the oil pressure in the transmission becomes reduced. It leads to operating irregularities of friction discs. Friction discs are special transmission components that are compressed or expanded, respectively, stopping/releasing the required speed gear inside the automatic transmission. If the fluid pressure decreases, frictions do not provide proper compression and start to slip and wear rapidly. Slippage raises the temperature and the fluid starts burning.

Problems with friction components mean that gears are not stopped/released at the right time. The driver experiences friction slippages in the form of jerks during gear shifting.

In some cases, gears cannot be actuated at all or the car can continue moving even when N gear is engaged. In the first case friction discs are heavily worn, while in the 2-nd case it can be assumed that friction elements get stuck. If the issue reaches such proportions, it won’t be solved only by the transmission filter replacement. It will be necessary to remove the transmission unit, perform diagnostics, and replace worn friction elements and other transmission components.

That’s how an automatic transmission oil pump looks like

The problem with fluid pressure losses in the automatic transmission can be caused not only by contamination, but also by issues with the automatic transmission oil pump. The oil pump can be positioned behind the valve body or in the transmission pan. The main purpose of this unit is to provide necessary pressure for the working fluid. If the pump performance drops, the transmission starts kicking and the driver can experience some jolts.

Automatic transmission problems are also frequently caused by issues with the valve body and solenoids. In fact, the valve body is a control element of the transmission. It consists of a wide range of channels, which transfer the working fluid to a separate gear. Solenoids, in turn, open or close the channels of the valve body. Solenoids are electric coils with a rod. Voltage comes to the coil, extending the rod, and blocks the channel. When voltage disappears, the spring pushes the rod back and opens the channel. Frequently, solenoids get out of order and stop opening or closing channels in the valve body. If solenoids do operate, but not correctly enough, the automatic transmission starts kicking and jerking during the process of gear shifting.

Automatic transmission valve body with solenoids

To solve the problem, it will be necessary to remove the valve body, disassemble it, and clean the channels. Then, it is required to check the operability of solenoids, and fix or replace the faulty element. It should be noted that jolts and kicks do not always occur due to issues with the transmission unit. Problems with the ignition system or the feed system, faults in the throttle area, or incorrect operation of ECM sensors can too have a negative impact on the automatic transmission operation.

That is why apart from automatic transmission maintenance, it is necessary to pay attention to the air and fuel filters, check the state of the spark plug and plug wires, flush the fuel injectors, clean and, if necessary, adjust the throttle unit, etc. For example, the automatic transmission can start jerking because of weak or strong tension of the gas pedal cable (if the gas pedal is electronic, the voltage in such pedal may also deviate from the norm). As a result, it may lead to jerks in the automatic transmission.

Summary

As you can see, there is a lot of potential causes for kicks and jerks in the automatic transmission. As a rule, if the automatic transmission starts working incorrectly, “A/T” or “Check Engine” warnings signals appear on the panel. In this case, it is necessary to visit the nearest repair shop for computer diagnostics to find out the source of the problem. However, diagnostics can be efficient if the problem lies in electrical components, but if the problem is caused by hard parts it will be necessary to remove the transmission unit and disassemble it to find a faulty element. It should be noted that in classic automatic transmissions (in contrast to CVTs) shifts from one gear to another can be accompanied by slight jolts (especially when driving without a warm-up) and they are considered as peculiarity of the transmission operation rather than a malfunction.

It should not be forgotten that so-called adaptive automatic transmissions adapt its operation to the driving style of the car owner, remembering certain parameters. Thus, when another person gets behind the wheel of such car, the process of gear shifting may seem hard and can be accompanied by jerks. It is caused not by any transmission malfunctions, but simply by the fact that the transmission requires some time to adapt to the style of a new driver.

It is Possible to Clutch Kick with a PDK Transmission

Sun, 06 Oct 2019 00:00:00 -0700

It is Possible to Clutch Kick with a PDK Transmission

In the past, manual transmissions ensured much better control and acceleration capacities compared to fast-shifting automatics. But new technologies implemented in automatic transmissions allowed to eliminate almost all advantages of classic gear stick solutions and facilitated to a slumping demand for manual cars. A well-known car enthusiast Matt Farah has recently proved technical superiority of automatic technologies, proving that it’s real to “clutch kick” with Porsche’s PDK transmission in a 911 GT3 RS.

First of all, let us clarify what is a clutch kick? On conventional manually shifted cars, a clutch kick is when the driver promptly disengages the clutch and reengages it by jabbing the third pedal all the way to the floor, then quickly releasing. This is to get the engine to rev up into its maximum power band by releasing the load from the drivetrain as if one were freely revving either in neutral or with the clutch pedal down. This trick allows a driver to significantly increase the drive wheels spinning.

7-speed PDK transmission

What’s the point of doing it? For instance, if you want to perform a powerslide trick when driving a RWD vehicle, without oversteering or accomplishing so-called “Pendulum Turn”, you can certainly resort to the mode of operation described above.

Check out how to clutch kick in the PDK-equipped Porsche

But is it possible to perform such a maneuver while driving an automatic car (such as Porsche’s PDK)? According to Mr. Farah, you have to disengage all the traction control system. Then, when driving, it is necessary to switch off the PDK’s clutch by using paddle-shifters and then push on the gas pedal. If fact, it can be named as a PDK’s clutch kick!

It’s hard to say how the frequent use of such feature will affect the PDK transmission parts, but it is certainly pleasant to know that you automatic Porsche has an operational parameter of a manual transmission.

Peculiarities of Fluid Change in CVT Transmissions

Tue, 01 Oct 2019 00:00:00 -0700

Peculiarities of Fluid Change in CVT Transmissions

Nowadays, many modern cars (passenger cars as well as SUVs) more and more often are equipped with a CVT transmission instead of a conventional automatic transmission. This is related to the fact that this type of transmission provides improved dynamic characteristics, better fuel economy, and this transmission is considered to be more convenient. Transmission fluid in CVT transmissions plays no less important role than in conventional automatic transmissions. Thus, well-timed changing of transmission fluid in the CVT unit is considered to be a key maintenance procedure.

In this article, we will consider the main peculiarities of fluid change procedure in CVTs, its time intervals, how to do it accurately, and what facts should be taken into account when choosing a fluid variant for your CVT transmission, as these questions often bother owners of Nissan, Renault, Mitsubishi, Subaru, Toyota models equipped with CVTs.

CVT fluid change: when and why it should be done

The fluid change procedure for CVTs is quite similar to the same maintenance service for automatics. However, it must be remembered that there are some procedure peculiarities and allowances specific only to CVT fluids. It must be emphasized that CVTs significantly differ from automatic and robotic transmissions in terms of design and principles of operation. This type of transmission is extremely sensitive to high loads and fluid quality. In fact, it means that CVTs are not intended for aggressive driving and harsh operating conditions.

As for CVT transmission fluid, with time it loses its properties, becomes contaminated with wear products, etc. In other words, even if the manufacturer claims that the transmission is maintenance-free, in reality, it is not entirely true.

As practice shows, experienced transmission repair specialists recommend changing fluid and filter in CVTs, automatic and robotic transmissions every 40-50 thousand kilometers. All these types of transmissions have one common component – a valve body. This complex and quite expensive unit is one of the most frequently repaired elements in automatically-actuated transmissions. It is the first component to get out of order because of contaminated oil. In case of operating under severe conditions, a fluid change interval is reduced to 30-35 thousand kilometers. Severe conditions include the following :

Towing;
Dynamic accelerations and slowdowns;
Long-time non-operation (idle) state in hot weather. When driving in traffic jams, there is no airflow to the CVT housing and cooling radiator, therefore the risk of overheating is significantly increased;
Off-the-road driving. Slippages of driving wheels can be quite harmful for CVT transmissions.

It is also worth noting that the deterioration of operation properties and contamination have a destructive effect on other parts of the CVT unit (belt, pulleys, cones, etc.) Given that it is difficult and quite expensive to fix a CVT, transmission fluid change should be taken very seriously.

How to check CVT fluid status

Drop test. Put a small amount of CVT fluid on a clean white napkin. Fluid opacity indicates a large amount of suspension of wear products from friction clutch packs, which negatively affects the oil channels and operability of the solenoids. The smell of burning indicates repeated overheating of the operating fluid, which usually occurs due to some issues with the CVT cooling system or pressure drops in the lubrication system. As a result, friction discs start slipping because of pressure drops, thereby causing fluid overheating. Depending on the year of manufacture and the transmission unit model, the CVT can be filled with a blue, green or red fluid. For a clear analysis of a drop specimen, it is desirable to have a sample of a new CVT fluid.

Fluid degradation counter (or simply fluid counter). The electronic control unit of many CVTs has a mathematical algorithm for calculating the residual service life of the working fluid. The calculation takes into account the total operating time of the CVT unit, fluid temperature and operating loads. The fluid counter calculates the oil degradation level in arbitrary measurement units. . The number of points calculated by the oil counter depends not only on the time of fluid operation, but also on a number of other factors, the main one is the temperature of operation. These points must be especially familiar to many owners of Toyota and Nissan vehicles. For instance, Toyota recommends changing the fluid when the counter reaches 210,000 points

To monitor the CVT fluid condition and fluid counter level in particular drivers can use CVTz50 software

However, two methods mentioned above do not always give you a 100% guarantee that the fluid will be changed timely. Therefore, transmission repair specialists recommend taking into account two rules:

Change fluid after purchasing a used car. Even if the previous owner will assure you that he changed the fluid before selling the car, it is better to be safe than sorry as CVT repair costs are usually quite high.
Adhere to recommended fluid change intervals specified in the car manual. But it is possible that you’ll have go against the manufacturer’s recommendation, as aggressive driving and severe operating conditions can bring the fluid change time much closer.

Fluid change in CVT transmissions

For CVT transmissions it is recommended to use only the original fluid under the brand name of the manufacturer. Usage of the third-party fluid is possible only if the product meets allowable tolerances of the original fluid. Operating characteristics of transmission fluids have been changing together with the development of CVT technologies. For example, CVTs installed in Nissan cars can be filled with fluids of NS-1, NS-2 or NS-3 classes. Before the fluid change procedure, it is necessary to examine the manual, where you’ll find some info on the filling volume and type of fluid.

When it comes to the fluid change, evidently there are two possible ways of action:

Visit a professional repair shop
Perform the procedure independently

When we are talking about possible fluid change methods, there are also two possible options: partial (incomplete) or complete fluid change.

Partial fluid change in CVTs implies so-called fluid refreshment. To put it simply, part of the lubricant is drained, and then it will be necessary to fill in exactly the same amount of fluid as has been drained and adjust the fluid level in the CVT unit.

To perform this procedure, firstly it is necessary to warm up the transmission unit by driving 10-15 km. Then you need to lift the car on a lifter and drain some part of used fluid. Then, exactly the same amount of fluid (the same manufacturer, properties, tolerances) must be filled into the transmission unit. This approach will help to avoid possible negative consequences of combining different types of fluid. It is important that with the use of this method you can refresh only 1/3 or a little more of the total CVT fluid amount. To achieve 100% refreshment of the fluid, this procedure must be repeated at least 3-4 times (with the interval of 500-700 km). It is also recommended to perform a double replacement of all automatic transmission filters.

Complete fluid change in CVTs is performed using a special device. The whole procedure implies a displacement method, when a new fluid actually squeezes out the old fluid out of the transmission unit.

The device is connected to nozzles of the CVT cooling system, and then the fresh fluid is supplied under pressure, squeezing out the used fluid. The device has inspection windows so that the technician can control the fluid pumping process, determining the degree of fluid condition by the fluid color. The main advantage of this method is the complete fluid renewal in the CVT unit. The special equipment also allows performing a flushing procedure before pumping fluid into the transmission unit.

DIY fluid change

If owners of CVT-equipped cars want to perform the fluid change procedure by themselves and do not have access to a special equipment, they should do the following:

Unscrew the plug and drain the old fluid;
Remove the transmission pan to remove any wear debris;
Replace the oil filter (if necessary it is also possible to replace the coarse mesh filter);
After cleaning joint surfaces, it is necessary to install a new gasket and attach the pan. Screw in the drain plug;
Fill in the new CVT fluid via the funnel inserted into the dipstick port. If the fluid level before the procedure was normal, the filling volume should correspond to the amount of old fluid;
Check the fluid level using the instructions specified in the manual;
Reset the fluid degradation counter. It can be performed with the help of many universal diagnostic devices. As practice shows, after changing fluid without resetting the fluid counter, the CVT unit starts operating with jerks and kicks. At the same time, CVT transmission repair specialists say about a peculiar trend: CVT belts and cones frequently get damaged after changing the fluid without resetting the fluid counter.

It is often claimed that a CVT-equipped car is more comfortable than automatic transmissions and a more reliable solution compared to DSG-type solutions. However, it is important to understand that CVT units are not intended for operation under severe conditions. In practice, it means that such a unit needs regular and quality service. At the same time, fluid change and filter replacement in CVTs are considered to be key procedures that transmission repair experts recommend performing every 40-50 thousand kilometers.

The Importance of Transmission Fluid Recycling

Thu, 26 Sep 2019 00:00:00 -0700

The Importance of Transmission Fluid Recycling

Transmission fluids (TF) serve as a lubricating agent, allowing transmission elements to move and operate properly. TF also provide cooling of the transmission unit and ensure smooth gear shifting. TF have a slick feel and are commonly red or green in color. Due to operation under severe operating conditions (high temperatures), TF becomes contaminated with wear products and eventually gets burnt (getting darker in color). It is a warning for a driver that the fluid must be changed. TF changing intervals depend on the type of gearbox unit installed in your car, type of car, and your way of driving.

Professional auto repair shops have to comply with strict requirements when it comes to disposal and recycling of auto materials (including TFs). No matter whether they just provide only maintenance services or a variety of transmission repair services, they must fully comply with the requirements. Actually, motor vehicles are one of the most recycled consumer goods on the planet. Hard components and TFs used in modern vehicles are frequently reconditioned and reutilized – sometimes even for another car or truck.

The same requirements and reasonable practices do not have a must-do-it status for common car owners. Today, many car owners can quickly and easily change TFs in their cars. As a rule, after each TF change they have a canister full of used fluid that lost its useful qualities. Subsequently, many drivers frequently do not know what to do with used oil and how to dispose of it. It this article, we will consider what should be done to used fluid.

Prerequisites for fluid recycling

According to the responsible authorities, TFs fall into the category of recyclable products. They can be recycled into new TFs, or burned to produce energy (which can be hardly called recycling, but it is a better choice than just throw this flammable fluid in the scrap heap).

Possible states of ATF used in automatic transmissions

TF can be based on oil products or synthetic materials. In any case, this type of lubricant is composed of several chemical elements that can be extremely harmful for ecology and environment. TF composition usually includes antifoamers to keep it from becoming too burbly, anticorrosive additives to exclude major failures and lubricating mediums to ensure smooth operation of the gear shifting unit. While these components have a positive impact on the gearbox operation, they can be dangerous for the environmental situation. TFs are not bio-degradable. If it is oil-based product, it is highly flammable. In such a case, it is a bad idea to put the TF in the trash.

What to do with used TF?

No matter what type of fluid (ATF, manual TF, or synthetic fluid) you have, when it is necessary to change fluid, you will have to find application for used TF. Like other types of auto fluids, ATF contains elements that can be malignant if ingested and polluting to the environment. Fortunately, TF is recyclable, so the right attitude to used fluid has a lot of positive effects beyond advancing operating characteristics of vehicles.

That’s how you dispose of automotive fluids in real life

So if you decide to change TF in your car independently, here are some tips when it comes to dealing with used TF:

First of all, make sure that you prepare a big enough container before draining the gearbox. Commonly, car transmissions can contain up to 3 gallons of TF at a time.
TF should be poured from the oil pan into a leak-tight storage reservoir. Use a funnel to prevent spilling. It is crucial not to mix TF with other types of fluid (unless otherwise specified by recycling companies) as the majority of recycling businesses will not work with mixed fluids. Keep it in a safe place.
Look for the nearest auto fluid collection company. Some specialized businesses will accept your used TF as well as other car fluids. It is also possible to browse through websites of governmental agencies to find a household harmful-waste accepting location near you. Finally, you can visit the nearest auto repair shop and ask if they will accept your used TF — some businesses may be happy to help you for free, as they will be able to make money on it.
When it is time to deliver TFs to a recycler, be especially careful when dealing with this undertaking. Make certain that the containers with TF are in full upright position, and drive carefully so they do not tip over.

Used TF should never be released into the environment, as it can be dangerous for all living beings. No matter whether you are just a car owner, auto mechanic, or owner of a small business or a large company, you should keep in mind that recycling of any type of car fluid is good for the environment and has significant economic benefits. Used TF is not a waste product, but a valuable resource that must be used wisely.

Mercedes-AMG's MCT Transmission: Design Peculiarities and Principle of Operation

Tue, 24 Sep 2019 00:00:00 -0700

Mercedes-AMG's MCT Transmission: Design Peculiarities and Principle of Operation

For car enthusiasts seeking a car with enhanced performance characteristics, the Mercedes-AMG’s model line-up is certainly one of the first that worth considering. The German brand integrates a lot of advanced performance-oriented features in its models, and some of these cars come with an unusual sports transmission named as AMG SpeedShift MCT. In this article we will consider the main design peculiarities of this unit, its modifications and principle of operation.

Mercedes-AMG, commonly known as AMG, is a division of Mercedes-Benz (subsidiary of Daimler AG), which produces more powerful and sports-oriented car models (or modifications) of the German Auto Giant, powertrain components (engine, transmission), as well as its own racing cars and represents interests of Mercedes-Benz in motorsport.

Learn more about SpeedShift MCT technology

AMG engineers designed the 7-speed semi-automatic SpeedShift MCT (Multi-Clutch Technology) gearbox on the basis of the 7G-Tronic. In contrast to conventional automatics and double-clutch solutions, this product has neither torque converter (TC) nor double-clutch mechanism. Instead of the TC unit, this solution is equipped with a space-saving clutch package, which operates in the oil bath. There are several clutches, which are positioned together, but controlled separately. This nsolution can be easily distinguished from doublel-clutch gearboxes because it has only one input shaft. Now, this transmission technology is available in 7-speed and 9-speed versions.

Seven-speed version

Produced in 2008, the 7-speed MCT unit became the first-of-its-kind technology implemented in a production car. In the same year, this solution was installed in the Mercedes-Benz SL 63 AMG. Owners of this model were impressed with operational characteristics of the gearbox and its responsiveness. AMG engineers wanted to create a product with impressive actuating time charactersitcs and enhanced torque transfer capacity, as a regular double-clutch mechanism could not operate properly with high volumes of torque produced by the V8 engines used in brand’s cars, so this technology had to be developed to gain max performance capacity.

In fact, this gearbox is a unique solution combining a planetary design used in conventional automatics and a clutch similar to that found in manual transmissions. Thanks to the minimum inertia of the rotating masses and higher reaction time, this transmission unit rules out interruptions in torque delivery (in contrast to standard automatics equipped with torque converters), thereby ensuring better fuel economy.

The AMG Speedshift MCT 7 unit is even lighter than the AMG Speedshift 7G-Tronic unit by 18%. The MCT unit weighs 80 kg, and the moment of inertia of rotating parts is reduced by 30%. This unit can operate at engine RPM rate of up to 7,200. This unit is used on quite powerful models of the AMG Series. The MCT unit has four modes of operation (C, S, S+ and M), a Race Start feature, and an automatic double-declutch function. The minimum shifting time is 0.1 of a second (S+ mode).

The whole mechanism is controlled by AMG DRIVE UNIT. Gears can be changed either via the gear shifter or with the help of paddle-shifters on the steering wheel. The newly introduced Race Start function ensures max speed-up capacity and optimal traction of the drive wheels.

Nine-speed version

The AMG Speedshift MCT 9 transmission firstly used in the E63 model became the 1-st in the world 9-speed multi-clutch automatic solution. To add two more gears, AMG engineers had to upgrade some hard parts of the unit. Moreover, they also had to introduce some changes to the software part and calibration adjustments to provide optimal operating characteristics. As a result, this transmission unit guarantees extremely quick gear shifting. As well as its 7-speed analog, the 9-speed Speedshift version can carry out several downshifts at once. Engineers preserved the double-declutch feature, improved RaceStart mode, and introduced a “coasting” function.

Application of Multi-Clutch Technology in different types of vehicles

This transmission technology is usually used in vehicles operating under severe conditions, where an ideal responsiveness is needed, along with the necessity to deal with a maximum level of torque. It should be noted that multi-clutch gearboxes are not the same as multi-plate clutches. The latter term refers to the clutch unit itself, which can be implemented in manuals. Multi-clutch gear shifting solutions find application not only in different types of racing cars, but also in heavy engineering industry. The main advantages of this technology are the following: space-saving design and enhanced transmission capacity when compared to standard automatics. In addition, transmission solutions with multiple clutches are not prone to slippages and they have significantly improved response time to pressing of the gas pedal.

It is not surprising that motorcycles have shifted to usage of multi-plate clutches. With extremely small dimensions, standard transmission units installed in motorcycles cannot handle high volumes of torque, while multi-clutch solutions turn out to be much more efficient. Most motorcycles are equipped with wet clutches, which operate in oil to avoid overheating. But, some motorcycles come with dry clutches, such as Ducati.

When it comes to passenger cars, dry clutches got wider use than the wet clutch technology, as the latter one is much more expensive. But some brands prefer the wet clutch solution because of its operating advantages. This technology found application not only in gearboxes, but also in modern differentials. The design of self-locking differentials includes multiple clutch plates inside, and they can engage or disengage axles depending on load.

Looking Inside EAG’s 2020 Supra Transmission Swap Project (Part 1)

Sun, 22 Sep 2019 00:00:00 -0700

Looking Inside EAG’s 2020 Supra Transmission Swap Project (Part 1)

Not so long ago, the tuning company European Auto Group (EAG) from San Antonio, Texas has started its manual transmission swap project for the 2020 automatic Toyota Supra. If you visit EAG’s youtube channel, you’ll see that the team of talented engineers led by Art Bartosik devoted itself entirely to this ambitious project, as new videos the transmission swap progress regularly reach their followers and the whole auto world. Go4trans.com has already highlighted some basic information on the Supra project in one of our previous articles. This time we want to delve into the technical side of the project with the help of numerous videos provided by EAG and learn more about the company itself.

It’s not a secret that the new Toyota Supra was designed in partnership with BMW, thus you can easily notice the similarity to the new BMW Z4 model. Both cars are based on the same platform, but they also have many different features typical for each brand. Since the new BMW Z4 sDrive20i gets a 6-speed manual transmission option, why not to offer this classic option to its design twin Supra from Toyota. According to the head of EAG Art Bartosik, the new Supra has a lot of tuning potential.

2020 Toyota Supra

In addition to the transmission swap, EAG wants to make the new Supra much more powerful, therefore they teamed up with some tuning professionals to upgrade the engine. To achieve this purpose, the EAG team performed numerous runs on Mustang and Dyno Jet stands on the 2020 Supra. Firstly, tests were performed in stock mode, then they used Stage 1 tune software provided by the Canadian company ProTuning Freaks. Eventually, after making several arrangements and adaptations they managed to achieve 422 hp and 420 flb of torque.

2020 Toyota Supra during Dyno testing

To add Supra some more power, Art and his team installed an upgraded turbocharger supplied by the Californian company Pure Turbos. To the same end, it was decided to get rid of the antifreeze and replace it with distilled water, which is supposed to bring the temperatures down. Moreover, they installed custom exhaust system and down pipe. Thanks to all these updates and some tuning magic from DME Tuning Lab Works, at the 1-st stage of tuning the project team managed to achieve impressive results: 527 hp and 462 flb of torque. But it seemed like these characteristics still had a room for improvement.

After analyzing Dyno testing data, the team noticed that they were running at high IAT (intake air temperature) rate (approximately 140 degrees). Thus, they pulled the frontend off this car and examined the cooling system, which turned out to be quite complex, therefore it was decided not to take any measures before the next Dyno testing.

As for some diagnostics procedures, the EAG team and its tuning colleagues decided to perform a complete EGS scanning of all computer systems of the 2020 Toyota Supra to figure out how these systems should be operated within the framework of this tuning project and ensure that traction control, steering angle sensors, braking, and engine input operate properly.

During the test drive of the 2020 Supra after the 1-st stage of tuning, the test driver was impressed by the engine power adjustments done by EAG and its big team of tuning pros. Despite the fact that the stock 8-speed automatic transmission installed in Supra is very smart, the only thing that was missing for the test driver was a manual transmission. After some data logging and engine mapping manipulations, the next Dyno test at JMS moved the engine performance characteristics to a new level (533 hp and 460 flb of torque).

The next step was to test this power on the drag strip and try to beat the ¼ mile speed record, but on the first try it didn’t work out well. After proper analysis, change of the tires, car weight reduction (220 pounds were stripped off the Supra), and when the automatic car professional got behind the wheel, Supra performed better, but Art and his team are absolutely sure that a manual transmission and a bit more tuning will help Supra to beat the record.

Check out the 2020 Supra modified by EAG on the track

But let us shift out attention from the “engine power quest” to the transmission unit that can be used for the 2020 Supra swap, namely a 6-speed manual transmission used in some BMW models. Some people may say that it should not be a big deal to take a 6-speed manual transmission from BMW and install it in Supra.

6-speed manual transmission GS6-45DZ that perfectly fits in a 2020 Supra

But it seems like this task is a bit more complicated than it seems. The thing is that the bell housing of the BMW (gs6-45dz) manual transmission available in the US does not match the Supra design and the starter in transmissions sold in the US is relocated (it is positioned between the intake maniforld and the engine block). But luckily, the European version of this transmission (installed in the 520d and some other BMW models) has the required starter positioning at the bottom of the bellhousing.

Special thanks to Art Bartosik for mentioning go4trans.com platform in one of his videos

That’s where go4trans.com gave a helping hand to the project. Art contacted us and asked us to help in search of the transmission solution for this promising project. We, in turn, got in touch with our UK partners from Sussex Auto Parts and Hydra-Test and they eagerly agreed to take part in this promising project. Thanks to the joint efforts of the companies, now the 6-speed manual transmission (gs6-45dz) is on its way to the US. According to Art, this won't just be a stock Supra with a manual gear stick, as the team is changing the design of the whole dashboard to integrate the new manual unit properly. At this point, the interior is in the design phase, but here is how it will approximately look like:

The shift knob you see here is just a show-piece, as EAG currently works on a custom-built knob with a flip-up button for sport mode, which will be offered as an option named 'The Concept Shifter.

Due to the fact that the factory warranty automatically terminates after any significant modifications, EAG will offer it will offer several warranty options on the transmission conversion service. EAG plans to perform 16 swaps within one year time period. Owners of the automatic 2020 Supra who want to get a manual transmission installed in their cars will have to loosen their purse-strings as a total cost of this service is $12,000. But if you are a manual transmission purist and want to stand out of the pack, it is worth it. EAG plans to present its manual 2020 Toyota Supra during the upcoming SEMA show.

More info on the project is to come…… Stay Tuned

About EAG

European Auto Group is a family-owned auto repair business headquartered in San Antonio, Texas. The company provides a wide range of repair and maintenance services for European auto brands (including BMW, Porsche, VW, Mercedes, etc). The list of EAG services includes the following: professional vehicle diagnostics, repairs and installations, timing belt services, welding and fabrication work, auto body customization and collision repairs as well as a wide range of performance services (from simple esthetic alterations to full custom design and performance tuning). The company also has a wide range of quality spare parts for European cars in stock. All services are performed by highly skilled and experienced technicians, therefore EAG offers a 1 year/12,000 mile warranty on all parts and workmanship. But the EAG team has become widely known to the auto world thanks to its manual transmission swap projects on automatic sports cars. The team of talented tech professionals has already unveiled to the auto world a one-of-a-kind Ferrari F430 Scuderia with a gated six-speed manual transmission. Now they have Ferrari 458 and 2020 Toyota Supra under way….

Automatic Transmission Filters: Types of Filters, When and Why is it Necessary to Replace Automatic Transmission Filters

Tue, 03 Sep 2019 00:00:00 -0700

Automatic Transmission Filters: Types of Filters, When and Why is it Necessary to Replace Automatic Transmission Filters

An automatic transmission is one of the most expensive components of automatically shifted cars. Automatic transmissions consist of a large number of electronic, mechanical, and hydraulic elements. Depending on the car model and rules of operation, the service life of the transmission unit can vary within different limits. In most cases, the car warranty usually expires by the time when the transmission unit gets out of order, thus drivers will have to pay for the transmission repair out of their own pockets. To postpone the moment of the transmission failure, drivers should not forget about premier maintenance services: ATF change and filter replacement.

Many drivers know about the importance of ATF change, but, unfortunately, they frequently forget about filter replacement. In this article, we will learn why it is important to timely replace automatic transmission filters, examine their types, and become familiar with their replacement frequency.

Why it is necessary to replace automatic transmission filters?

Automatic transmission fluid (ATF) not only lubricates the loaded transmission elements, but also transmit torque from the engine to the transmission (via the torque converter), and also engages gears by transmitting ATF under pressure through the channels of the hydraulic unit. As we can see, in modern automatic transmissions ATF performs many functions, therefore the quality of the fluid circulating inside the transmission unit is of paramount significance. And here transmission filters play a crucial role.

Filtering elements are installed in several major components of the automobile, including the automatic transmission. In fact, the main purpose of automatic transmission filters is to keep ATF clean from contaminants (wear debris, dirt, impurity elements), which can be harmful for the automatic transmission. At the same time, ATF must freely pass through the filter, simultaneously with the filtration ensuing necessary transmission capacity.

However, with the passing of time the automatic transmission filter gradually gets contaminated and it becomes impossible to pass ATF in necessary volume and under the needed pressure. Subsequent pressure losses have a negative impact on the transmission performance (jolts, kicks, slippages, etc.). These problems lead to rapid wear of friction discs, solenoids, and other transmission components.

Even timely ATF change (partial or full) without replacing the transmission filter does not solve the problem. In terms of automatic transmission wear driving with fresh ATF, but with a clogged filter, is not much different from driving a car with old ATF. Therefore, regular ATF change and filter change will help you to avoid the abovementioned problems.

Classification of automatic transmission filters

There are several types of filters, which are installed on different types of automatic transmissions. Transmission filters differ in the method of attachment, in filtering area, and filtering materials.

Depending on the positioning, all automatic transmission filters can be divided into internal and external filters. External filters are located on the transmission housing, and in most cases, they are attached to the housing by means of a thread joint. This type of filters can be found on old automatics. In terms of design, this filter resembles oil filters installed on engines. In most cases, this can be easily replaced with a new one. But at the same time, such filters have smaller filtration areas, therefore they are prone to rapid clogging (contamination) and fluid pressure losses. As a result, the automatic transmission equipped with such filter fails prematurely, if the filter is not replaced timely.

External automatic transmission filter

Internal transmission filter

That is why manufacturers came up with internal filters. These filters can be found on many modern automatic transmissions. Internal filters have larger filtration areas than their external analogs and they have significantly increased resource. On average, the internal filter has the replacement cycle of approximately 60-70 thousand kilometers.

However, internal filters are more expensive than externals and it is much more difficult to replace internal filters, as you’ll have to remove the transmission pan first to reach the internal filter (it will also be necessary to replace the pan gasket). Some cars have automatic transmissions with 2 filters (internal and external). In this case, the external filer should be replaced more frequently. On the one hand, this solution allows achieving better filtering of ATF. But at the same time, it also increases risk of fluid pressure losses, if any of these filters gets clogged with wear debris because of untimely maintenance.

Filter cartridge for JF011E

We should also pay special attention to the filter solution used in CVTs. The fluid for CVT transmissions must have additional anti-slippage properties, “gluing” metal of the cones (pulleys) to the transmission belt and thereby preventing their mutual slippage. Even the slightest contamination of CVT oil may lead to the transmission damage, therefore CVTs are equipped with additional external fine filters.

Inline transmission filter (used in Honda transmissions)

There is also an inline type of transmission filter, which found application in some Honda models. They should be replaced more often (10-15 thousand kilometers), as these filters are smaller and they get contaminated very fast.

Learn more about transmission filters from this cool video

Automatic transmission filters also can have different filtering material. Roughly, they can be divided into filters made of metal mesh and paper (felt filters or filters with so-called felt membrane).

Metal mesh transmission filter

Old automatic transmissions commonly have metal mesh filters. Such filters are notable for enhanced durability, as it should necessarily be replaced each time you change ATF. It is also easy to maintain such filters: just remove the filtering mesh when you notice that ATF becomes dirty and clean it with water. Such filters can be found today on some American and Japanese pickups as well as SUVs. This solution can perfectly deal with wear debris and other contaminants of medium size, but it is inefficient against small particles, which easily mix up with ATF and badly affect transmission parts. For this reason, it is necessary to change ATF more frequently in automatic transmissions with such filters.

Felt filter installed in automatic transmission 722.6

To prolong the service life of ATF and the transmission unit itself, modern automatic transmissions are equipped with paper (felt) filters. This material successfully deals with contaminants of various sizes. But at the same time, felt filters are not as durable as their metal analogs, and this filter must be replaced with a new one as soon as it gets clogged, otherwise ATF will be rapidly contaminated. Felt filers can have different number of layers (one, two or even three). Felt filters can stop not only fine friction and metal dust, but, most importantly, they prevent adhesive particles of worn friction components from mixing up with ATF. It saves valves and solenoids of the valve body from sticking.

Despite many advantages of multilayer felt filters, their design creates additional hydraulic (pressure) resistance to the transmission fluid flow, thereby creating obstacles for normal operation of the transmission unit at low temperatures.

How often is it necessary to replace transmission filters?

Filter replacement intervals depend on the transmission type, filter design, and ATF used for the particular transmission. The necessity of the transmission filter replacement together with AFT change is determined by the transmission model, filter model, ATF brand, and condition of ATF and filter. The information on intervals for the transmission filter replacement can be rarely found in car manuals. But it is necessary to replace the transmission filter in timely manner, if you want to prolong the service life of the transmission unit.

For metal mesh filters, firstly it is necessary to estimate its condition and then make a decision whether it should be cleaned or replaced with a new one. Some owners of cars with metal mesh transmission filters follow the rule: replace the filter during every 2-nd ATF change. The replacement intervals for metal filters can vary from 30 to 100 thousand kilometers. When using felt filters, it is extremely important to monitor the ATF condition. If the fluid becomes contaminated, then it’s time to replace the filter regardless of mileage. In practice, transmission repair specialists recommend to replace transmission filters in modern cars every 60-70 thousand kilometers (or 30-40 thousand kilometers when it comes to old cars) together with ATF change.

Summary

Considering the above, it becomes clear that the filter replacement is no less important as ATF change. Thus, in many cases these procedures are performed simultaneously. When planning automatic transmission maintenance services (filter replacement in particular), make sure that only high-quality filtering elements and ATF intended for a specific transmission model are used by transmission repair specialists. In some cases, when transmissions are equipped with external filters, drivers can perform the filter replacement independently. But the majority of modern cars are equipped with internal filters, and to replace them you’ll need a special repair kit to remove the filter, thus if you are not sure that you have enough knowledge and tools to do it, it is better to visit the professional repair shop.

Ideally, ATF change and filter replacement services must be performed timely with the use of OEM spare parts in certified service centers. It guarantees that all works will be performed in full compliance with technical requirements of automakers. Competent maintenance services will certainly prolong the service life of your transmission and avoid unnecessary repair costs.

Potential Consequences of Shifting Automatic Car into Gear While Moving Backward

Wed, 14 Aug 2019 00:00:00 -0700

Potential Consequences of Shifting Automatic Car into Gear While Moving Backward

Constantly accelerating pace and growing road traffic in cities often forces you to make hasty decisions when you are behind the wheel to reach the destination point in time, but in some cases it happens at the expense of the car’s operability. For instance, it has been widely debated on how it will affect the car equipped with the automatic transmission, if you shift your car from R to D gear while still moving backwards.

In fact, in case if your automatic car moves backwards really slow or rather crawls with the speed limited to 2-3 km/h, then you don’t have to worry much about possible negative consequences for your transmission unit. But if you decide to exceed this speed limit be ready to visit the nearest workshop for diagnostics and repair. To understand how this action of the driver affects the transmission, you have to understand the principle of operation of this complex unit.

Useful tips on driving an automatic car

Most automatics are fluid-operated units where the gearbox and the engine are linked by means of a torque converter that ATF flows through. When driving the ATF pressure will increase, thereby facilitating to precise gear shifting and smooth application of power to the wheels. These units are designed to ensure smooth and consistent feed of power to the wheels without experiencing any inconveniences.

The process of gear shifting in automatics occurs thanks to locking and unlocking the different parts of its planetary gearset. The locking of gears happens via clutches and bands facilitated by ATF. These clutches and bands are supposed to ‘slide’ a bit when engaging a gear thanks to ATF, which absorbs some of the transition, thereby ensuring smooth and safe gear shifting.

In practice, the situation discussed in this article may occur when you have to stop your car at a traffic light on hilly or elevating roads. When you release the brake pedal, the car will begin to slowly go backwards before power is transferred through ATF to force your car moving forward. The low speed in this case means shifting into D gear when moving backward is unlikely to cause any serious damage to the transmission mechanism.

Check out what happens if you put your automatic car in REVERSE while driving

But in case when your car reverses at higher speeds (5 km/h and higher), then it will be reasonable to bring your car to a full stop before engaging D gear. The same recommendation applies when it pops into your mind to engage R gear while traveling forward. Otherwise, you run the risk of seriously damaging one of the most expensive components in your car.

Why Mazda Avoids CVT Transmissions

Sun, 04 Aug 2019 00:00:00 -0700

Why Mazda Avoids CVT Transmissions

Among different types of car transmissions, CVTs are notable for not having gears at all. It uses a set of pulleys and belts to provide numerous ratios for a variety of driving situations. While it may seem like an ideal solution for some auto enthusiasts, as you won’t be bothering with gears driving this car, some car brands, such as Mazda, just disregard the CVT.

Mazda constantly designs smart engineering solutions for their cars. What many automakers may call an outdated technology, Mazda finds a way to upgrade and make much more efficient. Numerous automakers such as Nissan, Honda, Subaru, and Toyota have their valid arguments for using CVTs in their line-ups. But Mazda has its own plan of action relative to the powertrain solution employed in its models. For Mazda the gear shifting mechanism plays a great role in delivering Mazda’s unique level of “oneness between car and driver”. Mazda wants to have a bit more feel in their cars and to make them a bit more exciting to drive.

But it becomes more interesting when we pay closer attention to sales number of the Mazda model (in this case CX-5) compared to other cars in the SUV segment, because many CVT-equipped SUVs outsell Mazda’s automatic CX-5.

Model	Types of transmission	Sales
Toyota Rav-4	Auto	427,168
Nissan Rogue	CVT	412,110
Honda CR-V	CVT	379,021
Subaru Forester	CVT	171,613
Mazda CX-5	Auto	150,622
Source: GoodCarBadCar.net

Moreover, CVTs are known to be more fuel efficient because the system automatically sets the engine RPM rate in response to the power requirement of the car depending on particular driving situations. It is also claimed that CVTs ensure optimal power delivery and seamless shifting. Why did Mazda use to stick to its automatic and manual transmissions instead of choosing a more profitable CVT option? Let us try to sort it out.

Seems like Mazda’s decision to stick with its own powertrain solutions has more to do with the general vision of the company and its strategy rather than with sales volume. Even some representatives say that CVTs are not really the solutions the company wants and that CVTs cannot drive like Mazda. Therefore Mazda uses its own engine and gear shifting solutions known as SKYACTIV Technology.

Learn more about SKYACTIV-DRIVE technology

This technology was designed by Mazda engineers from scratch. It seems like a traditional automatic solution with a torque converter and a planetary set, but when you have a closer look at this technology, you can find interesting technical peculiarities of this 6-speed automatic transmission.

SKYACTIV-DRIVE 6-speed automatic transmission

Mazda claims that its SKYACTIV-DRIVE technology combines all benefits of standard automatics, CVTs, and dual-clutch gearboxes. This transmission solution ensures better responsiveness, rapid accelerations from a stop as well as quick and smooth gear shifting. This unit is equipped with an advanced control module (mechatronics), which facilitates to rapid and precise gear shifting. But main peculiarity of Mazda transmission is its upgraded torque converter system, which helped to improve fuel economy and ensured a more direct feel. It has a new lock-up device to prolong the time that the engine RPM is directly linked to the transmission rotation. The new lock-up ratio is around 80%, instead of the previous 50%. Expanding the lock-up range usually causes unpleasant noises and vibrations. Therefore, Mazda engineers designed a new mechanism named a full-range lock-up clutch (they use multi-plate lock-up clutch rather than a single-plate), they decided to use a smaller impeller and turbine for the converter to save space for a bigger lock-up clutch and a vibration damper. These steps helped to significantly improve torque transfer efficiency. Moreover, these interesting design solutions helped to enhance fuel economy (4-7% compared to standard gearboxes).

Check out a great video from EngineeringExplained on the topic

All in all, it is hard to say for sure whether Mazda’s automatic unit is better than traditional CVT solutions, but it can be said for sure that this technology helps Mazda to emphasize its technical distinctiveness and to stay away from the main drawbacks of CVT transmissions: high maintenance and repair costs, a “weird feeling” from driving a CVT-equipped car, noisy operation.

Oil Pans In Automatic Transmissions: Types and Design Peculiarities, Common Issues, Tips On Pan Selection and its Replacement

Thu, 01 Aug 2019 00:00:00 -0700

Oil Pans In Automatic Transmissions: Types and Design Peculiarities, Common Issues, Tips On Pan Selection and its Replacement

In automatically shifted cars an oil pan services as a so-called storage for ATF, and ensures for a convenient access point to the transmission filter and fluid. For automatic transmissions (ATs) ATF is vitally important, as it lubricates transmission parts and prevents overheating, thereby avoiding early wear of the transmission unit.

Oil pans also play a significant role in protecting ATF from different contaminants. The pan’s magnet helps to gather any dirt or debris from the fluid. This structurally simple component also helps to cool down the fluid before it is transmitted to the main gearbox components directly involved in the process of gear shifting. Pans also help to avoid mechanical damages to AT units from rocks or other obstacles met on the road, prevents rustiness and ATF oxidation. Apart from the stock pan, there are numerous types and variations of this simple, but extremely important component. Some pans can even enhance operational capacity of your AT unit. For instance, deep pans ensure better cooling, as your transmission can storage more ATF.

That’s how a standard transmission pan looks like

On average, AT units contain a bit more than 11 liters of ATF, while more powerful cars have the fluid holding capacity of up to 34 liters! Almost half of ATF is stored in the pan, while the remaining amount performs its direct lubrication functions within the AT unit itself. If transmissions need more fluid it means that these units operate more intensively for the purpose of dealing with the car’s engine power. ATs with more fluid have greater cooling characteristics.

Common Issues

An automatic transmission is considered to be one of the most frequently serviced and repaired components in modern cars, as numerous auto repair businesses mainly focus on transmission repair services. Transmission pans, despite their simple designs, also can get out of order in a number of ways. Transmission repair specialists point out the following possible issues in the oil pan:

When driving at high speeds, the pan can be deformed or damaged by some objects (rocks or other road debris) encountered on the road that could lead to fluid leakages. This results in faulty gear shifting operation;

Damaged transmission pan

Pan gaskets may change its positioning or get cracked because of the wear-out, resulting in ATF leakages;
Not tightly screwed up pan bolts or drain plugs may also lead to fluid leakages;

Transmission Fluid

Leak

How to prolong the service life of your oil pan

ATF pans can perform its functions properly for quite a long time, but it requires compliance with some basic maintenance measures:

Do not use cork gaskets and RTV sealants to ensure leak resistance of the pan. Cork gaskets are notable for unreliability and poor quality, thus they frequently wear out too early (it is recommended to use rubber gaskets). The use of RTV sealants, in turn, may lead to appearance of remaining materials (particles/debris) that contaminate ATF and end up on the pan surface;
Make a careful examination of the pan gasket during ATF changes. If it has any signs of wear, it is better to replace it with a new one;
Regularly check the pan surface for any symptoms of deformation or leakages;
Do not forget to properly clean up the pan surface and the magnet that gathers metal chips;
After the ATF change and the pan cleaning, make sure that you fasten the pan to the lower part of the AT in accordance with recommendations specified in the car manual. Otherwise, the pan can get damaged, and loose bolts can lead to leakages.

As the pan is exposed to any kind of impact from the external environment (i.e. the pan can be damaged by any obstacles that get under the wheels of your car while driving). Over time, the pan can become rusty or its surface may get some scratches and deformations, which will soon result in leakages. The same unfortunate result can be achieved, if the pan bolts get loose (or fall off). Thus, if you notice any signs of ATF leakages, it is highly likely that something isn’t right with the ATF pan.

If you ignore the abovementioned recommendations, it may lead to ATF shortages, which in turn, will significantly increase the wear of AT elements. As a result, your transmission won’t shift properly, and you will need an expensive repair.

Pan Selection

No matter how diligent you are in maintenance of your AT, and the oil pan in particular, but sooner or later you’ll have to replace your old pan with a new one. It is better to think about it before something goes wrong and find the necessary spare part in advance.

Manufacturers of powertrain elements and related spare parts can provide a wide range of varieties of the same transmission component to ensure the best performance characteristics, and the oil pan is not an exception. When it comes to replacement of your stock pan, you can choose from a wide range of pan options, depending on AT type, material used, ATF capacity, and cooling characteristics.

Ford C4 Steel Transmission Pan

Commonly, automakers equip their transmission solutions with stock steel pans. These pans are notable for their robustness and antirust qualities, and they turn out to be a budget-friendly option. In addition to affordability, it is very unlikely that the steel pan that you need will be out of stock.

GM TH400 Chrome Steel Transmission Pan

Frequently, you can also come across chrome pans made of steel with a chrome coating. In addition to much shinier appearance, chrome solutions are more maintenance-friendly (easy to clean) and more rust resistant than the abovementioned variant. But at the same time, chrome pans are a bit more costly than their steel analogs.

TH350 GM Aluminum Transmission Oil Pan Kit

Aluminum-made pans are considered by many experts as the best pan option available on the market. Aluminum pans have much better heat dissipation capacity and provide more efficient fluid cooling. In addition, this type of pans is much more robust and leak-proof than steel and chrome versions. But on the other hand, these pans are quite costly and it can be a challenging task to find the aluminum pan for a particular AT unit.

Other variations of pans

If you frequently expose your AT to severe operating conditions, it is recommended to consider installing a bigger oil pan with higher ATF holding capacity. Deep pans can store additional 2 or 3 liters of ATF. It may seem like a slight improvement, but for more powerful cars or cars frequently involved in towing/hauling operations deep pans can make a difference. More fluid helps to prevent overheating and to significantly prolong the service life of your AT unit. These pans also come in 3 versions (steel, chrome, aluminum).

Deep vs Conventional Pan

To enhance the cooling capacity of pans, some manufacturers include specials cooling fins or tubes in the structure of oil pans. However, such upgraded pans are more costly than standard stock or deep pans.

Allison transmission pan with cooling fins

GM transmission pan with tubes

Pan replacement

When it comes to the pan replacement, it should be noted that this procedure is not very complex and can be performed independently. Before starting the replacement procedure, it is required to ensure that you have all necessary new parts (gasket, pan, fluid) and tools (jacks, drain pan, screwdriver, etc).

Check out the video on how to replace the transmission pan

Now let us proceed to the pan replacement operation itself:

First of all, lift your car with the help of the jack to get access to the oil pan area;
Before fully removing the old pan, you have to drain all ATF. Some pans have a drain plug for this purpose, otherwise you will have to start unscrewing bolts one by one until ATF starts pouring out (do not unscrew all bolts before ATF is fully drained). Make sure that you use a drain pan to gather old fluid;
Remove the old pan, clean up the area and replace the filter;
Mount a new gasket to the new pan, and thread several bolts into it to keep it fixed. Ensure that the holes for the bolts in the gasket and pan match each other. Then insert and tighten remaining bolts in accordance with the recommendations from the manufacturer;
When you finish the pan replacement, it is necessary to refill ATF. If you have no idea of how much fluid is needed for your transmission unit, you can find this info in the car manual (fill a bit less fluid than specified there);
Start the car, shift through all gears, and let the fluid lubricate gearbox components. Check the ATF level with the help of the dipstick and add the missing amount of ATF.

Useful Tips on Driving Cars Equipped with CVT Transmissions

Thu, 25 Jul 2019 00:00:00 -0700

Useful Tips on Driving Cars Equipped with CVT Transmissions

Continuously Variable Transmissions (CVTs) have been around for quite a long time, but for some drivers this type of transmission still remains a mystery. CVT transmissions have certain design peculiarities, which have a significant impact on rules of operation of these units. In this article, we will consider the main aspects of driving CVT-equipped cars and learn how to avoid early visits to repair shops.

First of all, CVT transmissions significantly differ from other automatically-shifted transmissions (standard automatics or dual-clutch transmissions) in terms of design. Thanks to its design features, this transmission ensures smooth shifting without jolts, delays, or slippages. A car with this transmission accelerates easily without jerks, which to some extent can be experienced when driving cars equipped with automatic or dual-clutch transmissions. Other advantages of CVTs also include fuel efficiency (compared to automatic transmissions), better load distribution on the engine and transmission, which allows not to overload the transmission and to increase its service life.

Taking into account all advantages of CVTs, it may seem that this type of transmission can easily replace a conventional automatic transmission on the automobile market, but that’s no entirely true. The thing is that that many drivers with the experience of driving a CVT-equipped car complain about a noticeably smaller operational resource of CVTs compared to automatic transmissions, low maintainability of CVTs, high repair costs, and a wide range of limitations during operation.

Design basics of CVT transmissions

When it comes to design, CVT transmissions are quite simple. The structure of this type of transmission is based on two sliding pulleys. One pulley is connected to the engine, while the second one is attached to the driving wheels. The pulleys operate with the help of a special belt (or a chain). Each pulley is V-shaped, and its halves can smoothly converge and diverge. When both halves diverge, the belt (or chain) goes to a smaller radius, and at the converging stage the belt starts operating at a larger radius. The role of the clutch is performed by the torque converter or by the pack of disks, operating in the oil bath.

Learn more about a CVT transmission and its principle of operation

More advanced CVT solutions can emulate the operation of a traditional automatic transmissions – the control software forces the pulleys to converge and diverge not smoothly (as in standard CVTs), but in steps. Such a transmission shifts as an automatic transmission, making a driver to feel more comfortable when driving. This concept was successfully implemented in Lineartronic CVTs used in Subaru models.

Peculiarities of driving CVT-equipped cars

Despite numerous debates about its operational peculiarities and repairability characteristics, the CVT transmission technology has already gained popularity on the automobile market and some manufacturers of transmissions, such as Jatco, have high hopes for this type of transmission. At the same time, it is necessary to bear in mind that owners of cars have to comply with particular operation rules, which stem from CVT design peculiarities.

Cross-section JF011E- one of the most popular CVT units on the market

High Loads and Warm-up necessity

First of all, it is necessary to understand that CVT transmissions are not intended for high loads. To put it simply, when starting off the car equipped with the CVT transmission, you have to accelerate smoothly, gradually raising the engine speed. Otherwise, you’ll face CVT problems very soon. In practice, there are many cases when owners of CVT-equipped cars, who like rapid accelerations from traffic lights, started having transmission issues after travelling only 50-60 thousand kilometers. In addition, it is strongly recommended to warm up the CVT unit in cold weather. CVTs require sufficient lubrication (oil starvations are damaging for CVTs). At low temperatures transmission fluid distribution takes more time. It should be noted that CVTs cannot be warmed up the same way as conventional automatic transmissions (engaging all gears with a few seconds delay), as CVTs constructively differ from hydromechanical automatics. When it comes to the CVT warm-up, firstly it is necessary to warm up the engine and to engage the N gear for a few seconds. Then, you can start moving, at the same time minimizing the load on the transmission unit during the first 3-5 kilometers. It the temperature drops to -30 °C, then it is better to refrain from driving a CVT-equipped car.

Maneuvering and cornering

When driving a car equipped with a CVT, do not forget that this type of transmissions is very sensitive to increases of the engine RPM rate. In practice, first of all drivers increase the RPM rate by pressing the gas pedal, then the transmission control system will flexibly change gear ratios in accordance with the engaged gear and ensure that the engine operates in the most efficient manner. But this adjustment takes some time. If you make a maneuver while driving, you have to bear in mind the abovementioned peculiarity of CVTs operation. First of all, make sure that you achieve the necessary RPM rate and then perform a maneuver. The same applies to cornering: you have to press on the gas pedal at the moment when starting to turn the steering wheel.

Off-roading

CVTs are generally not intended for regular off-road use. Even if you are an owner of the SUV equipped with the CVT transmission, you should not get carried away with off-roading. Otherwise, you can easily damage the transmission getting into a road hump. If the mechanical damage occurs in the transmission unit, you may have to deal with serious consequences: from fluid leakages to the breakdown of main components. In any case, reckless off-road driving will result in costly repairs. The wheel slipping also can lead to rapid wear of CVT components. If you get stuck in dirt or a snowdrift, it is not recommended to try to get out of trouble by frequently shifting between D and R gears.

Transportation and towing

Passenger cars and SUVs equipped with CVTs are poorly adapted for towing and transportation of heavy loads. For this reason, it is not recommended to use a CVT-equipped car for towing of other cars; otherwise, it may lead to rapid wear of transmission components and complete damage of the unit. If the car manufacturer allows towing, be sure to examine its peculiarities in the manual. But in practice, towing of other cars leads to the transmission damage, especially when it comes to “old” CVTs. As for driving with a trailer, it is important that the trailer weight does not exceed permissible limits specified in the car manual. There may also be limitations on speed and distance to be travelled when using a trailer. If your car broke down in the middle of the road, it can be towed over short distances with the running engine. If the engine does not start, then towing can be performed only when the axle shafts are disconnected from the drive wheels. But ideally, in such cases it is desirable to call a tow truck in order to avoid additional risks.

Great video from Engineering Explained on things you should never do when driving a CVT-equipped car

CVT maintenance

When it comes to CVT maintenance, the main point is the transmission fluid status. It is critical to regularly check fluid condition and its level. CVTs operate with special types of transmission fluid ensuring lubrication of the interacting surfaces and preventing slippages. CVT fluids must be changed more often than in automatic transmissions. It is also recommended to use CVT fluids specified by the car manufacturer. According to manuals, it is necessary to change CVT transmission fluid once every 60 thousand kilometers, but in practice it is desirable to perform this procedure every 30-35 thousand kilometers.

If we talk about possible failures of electronic components, it is necessary to pay close attention to the state of separate EECS sensors. Problems with these sensors may lead to additional loads on the CVT unit, resulting in its failure. Constant monitoring of sensor operating condition is a must. One faulty sensor can lead to the failure of the whole unit. If the speed control sensor is damaged, the control unit automatically switches the transmission belt to the emergency position, the engine starts braking urgently. In this case, there is a high risk of the belt deformation (or even its damage when driving at high speeds). For those who buy a used car equipped with the CVT transmission, the first thing to do is to replace the speed sensor (it is desirable to buy the original part from the manufacturer). The same applies to oil level and pressure sensors. The entire set of sensors must be in good operating condition.

Summary

To sum it up, it can be assumed that CVT transmissions can ensure more comfortable and fuel efficient driving compared to classic automatic transmissions. However, it should be borne in mind that this type of transmission is not intended for high loads and severe conditions (overheating is lethal for CVTs). To put it simply, CVT-equipped cars are more suitable for the use on good urban roads and for drivers with a calm driving style (without abrupt starts, slippages, frequent overtakings).

To keep the CVT transmission in perfect operating order you have to do the following:

Ensure timely maintenance servicing;
Monitor transmission fluid level and its condition;
Warm-up the transmission before taking off;
Avoid excessive loads.

When complying with these rules, your CVT transmission will accurately operate during the entire service period specified by the manufacturer.

How to Convert 2WD Transmission into 4WD Transmission?

Thu, 18 Jul 2019 00:00:00 -0700

How to Convert 2WD Transmission into 4WD Transmission?

The 2WD and 4WD versions of automatic and manual transmissions have a lot of design similarities. They have similar housing units, gear ratios and frequently have the identical spline connection on the output shaft. The main differences between these two units lie in the fact that the 2WD output shaft is longer than the 4WD version and 4WDs are connected to a transfer case. Some carmakers manufacture their 2WD transmissions in such a way that they can be transformed into 4WD models.

A 2WD transmission is drive recognized by its extended tail shaft with the rear-end part including an overdrive unit. The 4WD transmission also has such unit, but it is paired with a transfer case that transfers the power to both axles. The 2WD gear shifting units have no transfer case. However, some cars are equipped with a dummy transfer case to significantly simplify the process of conversion to 4WD (only a 4WD output shaft will be needed).

Transfer Case

If you see the transfer case connected to the rear-end of the gearbox, you can say for sure that you are dealing with a 4WD car. However, some 2WD cars also may have a dummy transfer unit providing an opportunity for 4WD conversion in the future. A transfer case is intended for distribution of torque from the gearbox between 2 axles with the help of 2 shafts. It also syncs up the discrepancy between the RPM rates of the fore and back wheels, and may be equipped with one or more sets of low range gears for off-highway application.

Learn more about a transfer case

The gear shifting mechanism in 4WD cars without a transfer case has a special gearbox design. The 4WD versions of passenger cars (that are not intended for off-road driving) are designed on the basis of a standard passenger car. Some models are designed only for 4WD application and have no 2WD analogs (for example, Subaru and Jaguar X models).

The FWD models with a longitudinal powertrain positioning (majority of Audi cars) are the easiest to be redesigned to 4WDs. In such a case, torque is transferred to the back axle from the transmission via the shaft/cardan drive. The rear axle is complemented by the main gear, while the central/interaxle differential is embedded in the transmission housing. If you want to convert a RWD car with the front engine positioning into 4WD, you will certainly need a transfer case and a central/interaxle differential, attached to the transmission. Here torque is distributed asymmetrically, most of which is transferred to the back axle. The main gear with independent suspension of the front wheels is connected to the body. It is much more challenging task to convert 2WD transmissions in FWD cars with a transverse engine into 4WD. In this case, the main gear housing ( картер главной передачи) is positioned behind the engine and the cardan gear is used for connection of the front main gear to the additional rear axle main gear. The 4WD conversion for a 2WD car with central engine positioning is too complex, thus such complex design transformations are rarely implemented.

To perform the 2wd to 4wd conversion operation you will certainly need an adapter kit

Actually, a standard 4WD system includes the following components:

Manual or automatic gearbox;
Transfer case;
Center differential;
Cardan drive;
Rear and front differentials.

2WD to 4WD conversion: Does the end justify the means?

The value of 2WD to 4WD conversion became the subject of sharp debates on automobile Internet forums.

Learn more about 4WD systems

Nobody disputes that the 4WD transmission gives you a lot of important advantages. It is obvious that in addition to significant improvements in off-road driving (if we are talking about SUVs), a 4WD vehicle performs much more efficiently when driving on slippery roads and provides more intensive acceleration. Four driving wheels improve dynamics and stability of a car on the road, and sharp starts without slippages are not a problem for a 4WD car. Some people claim that the conversion to 4WD is not that hard and can be performed even without a complete transmission disassembly.

However, according to numerous posts on auto internet forums, where this question is actively discussed, 2WD-to-4WD conversion can become a real pain in the neck, because this procedure may include a complete transmission reassembly and replacement of numerous parts. The 4WD conversion implies additional weight and power losses, which have a negative impact on the vehicle’s overall performance capacity (lower top speed) and fuel efficiency. Breaks and tires will wear out much faster.

Some people say that by converting the vehicle 2WD to 4WD the additional weight will put an extra load on chassis and numerous elements of the car. So you also have to modify/replace the other parts of vehicle to deal with additional loads. The engine repositioning may also be needed. Some users claim that you may have problems with balancing. In some cases, entire suspension may have to be changed including lower arm. If we are talking about cars equipped with advanced and electrically operated automatic transmissions, it is hard to predict how the conversion to 4WD will affect the operation of the transmission software and its numerous sensors. Therefore, it is assumed by many that it is better to save your time and money, and save up money for a 4WD car.

Conversion of 6L80 2WD transmission to 4WD

We will use examine the conversion process using the example of the GM automatic transmission 6L80. This 6-speed automatic transmission is an extremely popular OEM unit and an amazing conversion transmission thanks to its adaptability. The process of 2WD-to-4WD conversion for this transmission is not very complex and includes the following steps:

Remove the tail shaft housing;
Remove the O-ring as well as the sleeve;

You’ll see three open areas: 2 holes (used in the 2WD unit for lubrication of the output shaft bushing) and place for a 4WD seal;

Install a 4WD output shaft seal (make sure that this part is completely flushed);

As for the two holes, it is required to install two solid plugs. These plugs block ATF from reaching the back-end of the gearbox and send it back into the pan. In the 4WD version, it is not necessary to lubricate anything, because you have a transfer case attached to it. When installing the plugs it is desirable to use a little bit of thread-locker compound (do not use Teflon tape);

Cut the 2WD output shaft as specified in the manual that comes with the adapter;

Install the 4WD adapter (4WD tail housing) and test fit the transfer case.

6L80 conversion to 4WD

All in all, it can be concluded that the complexity and reasonableness of the 2WD-to-4WD conversion largely depends on the transmission type/model, its design peculiarities, as well as on the structural design of the car in which this transmission unit is installed. In fact, some transmissions such as 6L80 are terrific conversion transmissions thanks to their adjustability, while other transmission units may require much more efforts to make them 4WD.

In many cases, automakers standardize their car models to be equipped with different types of engines and transmissions with different drive configurations. Thus, the conversion process in such car models is not something supernatural and does not require significant changes in the structural design, but at the same time to perform it properly you need technical knowledge and some special tools. If you are not sure that you can perform this operation properly and you badly want to convert you 2WD transmission into 4WD still, you can buy all necessary parts on the internet and find a professional workshop providing swap services.

4WD systems: Types, Peculiarities and Principles of Operation

Fri, 12 Jul 2019 00:00:00 -0700

4WD systems: Types, Peculiarities and Principles of Operation

The design of a four-wheel drive vehicle ensures the capacity of transmitting torque from the engine to all four wheels of the vehicle. Structural arrangements of 4WD systems allow realizing the full power potential of the car, its road handling, active car safety. The four-wheel drive car can be abbreviated as 4x4, 4WD, or AWD. In this article we will review different types of 4WD (AWD) car systems, peculiarities of their structural arrangement, transmission layout in four-wheel drive cars.

The main design feature of the 4WD (AWD) vehicle in comparison with front-wheel drive and rear-wheel drive variants is the presence of an additional unit in the transmission system – the transfer case. In fact, this unit is responsible for torque distribution between two axles of the car. Another design difference between 2WD and 4WD transmissions lies in the fact that the 2WD output shaft is longer than the 4WD (AWD) version.

Learn more about 4WD systems

In general, the 4WD design includes the following components:

Manual or automatic transmission;
Transfer case or multiple-disc clutch;
Interaxle/center differential;
Cardan drive;
Rear and front differentials.

Drive Types

We will consider 4 types of drives:

Full-time 4WD;
On-demand 4WD;
Part-time 4WD;
Selectable 4WD.

Full-time 4WD

This drive system differs from others in that torque is constantly distributed to all wheels simultaneously. This type of drive can be implemented on different types of vehicles (SUVs, sedans, hatchbacks) regardless of the engine positioning (longitudinal or transverse). At the same time, the transfer case in this system has a reduction gear, which can be activated with the help of an electronic actuator (the driver simply selects the required mode via the selector and the servo mechanism performs switching).

Audi Quattro

The presence of a center differential is a distinctive feature of the transfer case in the full-time 4WD. This system design has a locking mechanism for the center differential to use the full potential of 4WD. The self-locking differential can distribute power between axles in different amounts for maximum efficiency. The center differential locking in modern 4WD cars is implemented automatically by means of a viscous coupling, self-locking differential Torsen, or multiple-disc friction clutch.

BMW xDRIVE

Mercedes 4Matic

It should also be noted that full-time 4WD of modern cars are mainly controlled by electronics. The most known full-time 4WD systems are the following: Audi Quattro, BMW xDrive, and Mercedes 4Matic. Electronic systems in cars with permanent 4WD receive different signals from numerous sensors (for example, wheel speed sensors), after that the system almost instantly changes the ratio of transmitted power. Moreover, the electronic system also takes into account road conditions, possible wheel slippages, etc. Cross-axle differentials in full-time 4WDs are also equipped with locking mechanisms, but not always (they are not usually used on sedans and hatchbacks). Cross-axles are not necessarily to be installed on two axles; frequently such mechanism can be used on only one axle.

Principle of operation of full-time 4WD

First of all, the torque from the engine is transmitted to the gearbox and then to the transfer case. In the transfer case, the torque amount is distributed between front and rear axles. Subsequently, the torque is transmitted to the main gear through cardan shafts, and then to the center differentials of both axles. From the differential the torque is transferred to the drive wheels. If wheels of one of the axles start slipping, then the differential locking mechanism is actuated. This type of 4WD is considered to be one of the best solutions available on the market, because this system can significantly increase active safety and dynamics of the car.

The main drawbacks of this system are increased fuel consumption and higher loads on all 4WD transmission components, which reduce the resource of the main components, especially under the condition of aggressive driving.

On-demand 4WD

4Motion system from Volkswagen

This four-wheel drive system is activated only under certain conditions: when the wheels of the constantly operating axle start slipping. The rest of the time, the car with this 4WD system is either front-wheel drive (with transverse engine positioning) or rear-wheel drive (the engine is positioned longitudinally). Almost all leading automakers include this type of 4WD in their model line-ups. The most popular on-demand 4WD solution is 4Motion from Volkswagen. This system has some design peculiarities. The transfer case in this drive type has a simplified structure and it has no reduction gear, but at the same time On-demand 4WD ensures constant distribution of torque between axles. There is also no center differential, but this system has a smart mechanism for actuation of the “true” 4WD. It is noteworthy that this mechanism uses the same components as the center differential – viscous coupling or friction clutch with electronic control.

Principle of operation of On-demand 4WD

Torque from the engine is transmitted via the clutch, gearbox, rear-axle drive and differential – to the front axle of the car. Through the transfer case and cardan shafts torque is also transmitted to the friction clutch. In the normal position, the friction clutch has a minimum compression, at which up to 10% is transmitted to the rear axle. When the front axle wheels start slipping, the electronic control unit actuates the friction clutch and transmits torque to the rear axle. The amount of torque transmitted to the rear axle can vary within certain limits. This type of 4WD is considered by many specialists as one of the most promising solutions: under normal operating conditions you use only 2WD without putting additional load on powertrain components and save more fuel, but when needed the 4WD system is activated with the help of the transfer case.

Part-Time 4WD

If you need a reliable 4WD solution intended mainly for off-roading rather than driving on urban roads, the Part-Time 4WD system will be the best choice. This system ensures a rigid connection between the front and rear axles and torque transmission in the ratio of 50:50, therefore it can be considered as a great off-road option. Moreover, the part-time 4WD design is much simpler than the abovementioned versions: there is no center differential and locking mechanisms, there are no excessive pneumatic or hydraulic components. The rear axle in the system is the leading one, and the front axle is actuated by the driver. Torque is transmitted to the front axle when the driver engages the transfer case with the help of the lever and/or buttons.

This system will not allow you to drive at high speeds on solid surfaces, because equal torque distribution leads to slippages of wheels, which, in turn, entails extra loads powertrain components, rapid wear of tire, deterioration in road handling at high speeds on solid road surfaces. Therefore, nowadays this system is rarely used by car manufacturers.

Selectable 4WD

It should be noted that there are also combined 4WD versions, which include features of several drive systems mentioned above and they are designated as Selectable 4WD. In other words, the 4WD mode in these systems can be actuated manually and automatically (at the same time you can disengage any of the axles, if needed). The same applies to locking mechanisms in center and cross-axle differentials.

In this category we can point out the following models: Mitsubishi Pajero (Super Select 4WD), Jeep Grand Cherookee (SelecTrac), Nissan Pathfinder (All-mode 4WD). These systems can be considered as Full-Time 4WD with the capacity of forcible disengagement of the front axle. In Pajero, for example, you can select one of the following modes of operation: 2WD, 4WD with automatic locking of the center differential (analog to Full-Time 4WD), 4WD with a rigidly locked differential (analog to Part-Time 4WD), and low range Part-Time 4WD.

There is also an electromechanical 4WD option. In this case, all torque is transmitted to one axle only, while the second axle is equipped with electric motors, which are activated only in the automatic mode of operation. Thanks to the rapid development of environment-friendly technologies in the automobile industry, this solution becomes more and more popular. In the classic sense, it can hardly be called as the 4WD system, but rather a hybrid drive version.

Pros of 4WD

The key strengths of 4WD are traction and power. If you are driving on a steep hill or off-roading you will certainly need additional power that comes with 4WD.

4WD enhances traction parameters in hazardous driving conditions, such as snow, ice, rocks, and other cases that can cause trouble for a driver. When torque is distributed to both axles, traction and car handling gets much better.
Extra weight facilitates to enhanced road-holding capacity.
Hard acceleration without slippages of the wheels, while in case with 2WDs such accelerations are likely to result in slippages.

If you often drive on road surfaces with low traction, or if you enjoy off-roading, you will greatly benefit from four-wheel drive.

Cons of 4WD

Enhanced fuel consumption;
Expensive repair and maintenance;
Additional components (differentials, transfer case, etc.) make this system much more complex and consequently there are more elements that may fail;
Operation under severe conditions adds extra load on the powertrain components, thereby increasing their wear;
Owners of 4WD vehicles can get carried away with driving too much under severe conditions and eventually get stuck even with 4WD.

If you drive mainly on urban roads under good weather conditions, then it is no use for you to spend more money on the 4WD car, but is more reasonable to stick with the 2WD option.

4WD Tips

4WD cars operate in the most efficient manner, when they are regularly used and serviced in accordance with recommendations provided by the automaker. If you do not engage the 4WD system for a long period of time, the seals can get dry. It is necessary to keep the system lubricated by engaging it at least once every few months.
It is desirable to engage 4WD when you really need it to save as much fuel and money as possible. Driving 4WD under normal road conditions can be damaging for the front axle, differential gears, and other powertrain elements. Stick to 2WD on dry pavement.
If you get stuck, activate 4WD and slowly release the gas pedal to get yourself out.

Typical Issues with Downshift Solenoid and its Replacement

Thu, 20 Jun 2019 00:00:00 -0700

Typical Issues with Downshift Solenoid and its Replacement

Modern automatic transmissions are quite complex components of automobiles consisting of numerous elements that operate in conjunction to ensure smooth gear shifting. These sophisticated units function with the help of hydraulic pressure to implement the process of gear shifting itself, and utilize valve body solenoids to handle the pressure of the ATF to specify the shifting points. There are many solenoids responsible for different gear shifting operations, and in this article we will have a closer look at downshifting solenoids.

4L60E Downshift Solenoid

The downshift solenoid is responsible for shifting from a higher speed to a lower speed, for example, in cases when the car is decelerating to a stop. When this solenoid gets out of order, it may have a negative impact on the car’s shifting capacity. Commonly, a driver can understand that his car shifts weird because of a defected solenoid due to the following symptoms:

Unsteady shifting

One of the most vivid signs of a faulty downshift solenoid is unsteady shifting. If something is wrong with this solenoid, it may force the car to behave unstably during downshifting. Thus, when you have to deal with hard or erratic shifting before stopping your car, the chances are high that the downshifting solenoid has failed.

Shifting delays

Another known sign of an issue with the downshift solenoid lies in gear shifting delays. The gearbox may stay engaged in a higher gear during the time when it should already shift to a lower gear. This will cause needless RPM boosting, and may cause an extra load on the powertrain components.

Malfunction indicator lamp

A malfunction indicator lamp (MIL), or check engine light, frequently pops on when the electronic management unit of your car detects some deviations from operating standards. The thing is that this warning mechanism will inform the driver not only about the faulty downshift solenoid, but also about a wide range of other issues. Thus, if you have suspicions about operability of the downshift solenoid, then it is needed to visit the nearest repair shop for diagnostics and scanning of error codes.

Downshift solenoids are relevant valve body elements, ensuring proper downshifting. If you disregard the abovementioned symptoms, it may lead to more serious problems with the whole gearbox unit and consequently pricey repair.

Replacement

If you decide to replace a faulty downshift solenoid by yourself, it is necessary to follow several simple recommendations. Before you start, make sure that you have all necessary tools to perform this operation safely and accurately (drain pan for ATF, nippers, jack, jack stands, ratchet wrench, special gloves, new spare part, etc.) Then, you have to perform the following:

Lift the car with the help of jack stands;

Drain out ATF by removing the plug from the pan

;

Carefully disconnect the ATF pan itself with the help of the wrench;

Find the exact fitting place of the downshift solenoid in the car manual or search the info on the Internet;

Solenoid identification and location using the example of 4EAT

Remove the defected element;
Mount the new solenoid;

Reinstall the gearbox pan cover;
Fill in the necessary amount of ATF recommended by the automaker;

Remove the car from jack stands;
Perform a test drive and pay attention to the downshift solenoid operation.

If you are not sure that you can perform this procedure accurately, then it is better to entrust this job to professional technician, otherwise you will only make the matter worse.

Useful Tips on Driving Cars Equipped with DSG Transmissions

Tue, 11 Jun 2019 00:00:00 -0700

Useful Tips on Driving Cars Equipped with DSG Transmissions

Progress does not stand still as new technologies emerge in the automotive industry every day. Special attention should be paid to significant achievements of automobile engineers in the field of automobile technologies. Pre-selective transmission technologies gained significant popularity with the release of DSG6 (DQ-250) and DSG7 (DQ-200) transmissions designed by Volkswagen.

Cross-section of DSG6 (DQ250)

Cross-section of DSG7 (DQ200)

DSG is an automated manual transmission equipped with 2 clutches and a separate control unit called Mechatronics. Nowadays, DSGs are considered to be one of the most common robotic transmissions offered on the market. Despite numerous advantages, DSG transmissions are quite complex and often cause criticism among common drivers because of numerous repair issues. Thus, it is necessary to take into account some peculiarities of these transmissions and adhere to some operating rules to prolong the service life of these sophisticated units. In this article we will consider the main recommendations on practical usage of DSG transmissions.

How to Use DSG Transmission Properly

DSG units combine the dynamics of manuals and the comfort of automatics. VW engineers made a lot of efforts to design an ideal transmission solution. Despite numerous drawbacks in initials designs of DSGs, experts consider pre-selective gearboxes to be one of the most promising transmission technologies. Currently, the automotive market follows the trend of comprehensive automation of all car systems. Despite similarities of DSG transmissions to manuals (in design) and automatics (in operating principles), driving a car equipped with a DSG differs from cars equipped with other types of transmissions (manual transmission, CVT, automatic transmission, robotic transmission with a single-plate clutch).

DSG6 vs. DSG7

Moreover, DSG operating rules differ depending on the DSG model (6 or 7) installed on a particular car model. The thing is that the DSG6 transmission is equipped with a “wet” clutch (this clutch operates in the oil bath), while the DSG7 unit has a “dry” clutch. With time clutch discs on both DSG models wear out, but in case with DSG7 it happens much faster. It means that an aggressive driving, sudden accelerations from a standstill are strictly prohibited for DSG7, while with DSG-6 units such situations are tolerable.

DSG transmission explained

The thing is that “wet” clutches operating in oil baths are more protected from wear and overheating than their “dry” analogs. Moreover, the DSG6 system was originally designed for more torque (about 350 Nm), while the 7-speed version can handle no more than 250 Nm. In practice, it means that the chip-tuning and severe operating conditions will rapidly “kill” the DSG7 system. If these recommendations are neglected, the new DSG7 transmission may get out of order even before covering 50-70 thousand kilometers, resulting in highly-priced repairs.

How to use DSG transmission properly in traffic jams

It is not recommended to set the gear selector to N position. Modern robotic transmissions drop out of meshing simply by pressing the brake pedal. In other words, when the brake is pressed, the car is in neutral.
Do not drive very short distances frequently alternating gas-brake pedals. Each time when you release the brake – it's as if you release the clutch, it automatically starts coming into contact with the flywheel, and it slips due to incomplete contact. When you release the brake and start driving at a speed of 5-6 km/h, then the full engagement takes place.
Let the car in front drive at a distance of about 5 meters from your car and follow this car at a low speed in first gear.
The resource of DSG6 and DSG7 directly depends on whether the transmission in a traffic jam will shift to the 2-nd gear or not. Frequent shifts from the 1-st to the 2-nd gear and vice versa in traffic jams will kill any robotic transmission with 2 clutches (clutch and flywheel wear and overheat). To avoid such situations, it is better to switch to manual control. To put it simply, drivers independently engage the 1-st gear and do not shift to the second in the situation described above.

Info on operating DSG transmission from Volkswagen

More rules and recommendations on DSG transmissions

To enhance the resource of DSG transmissions, experts also recommend active pressing of the brake pedal when shifting gears. If drivers step on the brake pedal not hard enough, the DSG mechanism does not fully open clutch discs, thereby increasing wear of this transmission component. It is also important to bear in mind that the “shifting to N” rule during stops relevant to robotic transmission with a one-disc clutch affect DSG transmissions to a lesser extent. In other words, it is not necessary to engage N gear at traffic lights and when idling for up to 60 seconds, as frequent gear shifting leads to wear of transmission components.

DSG transmissions (especially a 7-speed version) are even more sensitive to slippages than automatic transmissions. Thus, it is strictly prohibited to slip in the mud, on ice, and when starting from a standstill in the manual mode. When parking the car equipped with the DSG transmission, it is necessary not only to shift to the “Parking” gear, but also to engage the hand brake in order to prolong the service life of a special blocking mechanism, which prevents the car from rolling back. Gear shifts must be smooth, with a slight delay of about 1 second. During this time, the electronic part of the transmission manages to adjust to the process.

Useful tips on driving a car with a dual-clutch transmission

It should be added that a car equipped with the DSG transmission should not be overloaded by towing a trailer or other vehicle, as well as heavy loads in the car itself. In practice, cars (heavy in themselves) equipped with the DSG-7 transmission (for example, Skoda Superb) with the cabin full of passengers and additional cargo can weight about two tons. Taking into account that this transmission is not intended for heavy loads, it can fail because of overloading. As for the DSG6 unit, this transmission is more durable and operates in pair with more powerful engines. However, it doesn’t mean that a car with this transmission can always be used for towing.

DSG transmissions require more frequent maintenance servicing than manual transmissions. For example, the clutch in the DSG6 transmission operates in oil, and the volume of required lubricant is quite large. For this reason oil changes in the DSG system must be performed every 60 thousand kilometers. In addition to oil, repair specialist also have to replace the transmission filter. These operations should be performed by professional technicians who have necessary equipment. If your DSG-equipped vehicle gets stuck in mud or snow, it is not recommended to push-start (kick-start) your car. It is desirable to engage the N-gear and call a tow truck to avoid possible transmission issues. If it is necessary to tow a car equipped with the DSG transmission, it is necessary to follow the rules and recommendations specified in the car manual.

Mechatronics unit

DSG Mechatronics unit

The mechatronics control unit is quite vulnerable unit which requires regular checks. Moreover, this unit can be easily overheated. Plastic tubes transmitting coolant to the heat exchanger frequently turn out to be a soft spot for DSG transmissions. These tubes crack and break off because of vibrations. But even if, technically, the transmission is fully operational, it is enough to get into a long-time traffic jam, holding the car with a brake, to overheat the control module. In such cases, cars with automatic transmissions or CVTs will be OK, but for DSG, as even VAG says in its manuals, if the car stays in the jam longer than a minute, it is necessary to shift to the N gear in order to avoid overheating of the mechatronics unit. In particular, “dry” DSGs regularly fail for this very reason.

All in all, DSGs cannot be considered as the most reliable solutions due to numerous drawbacks related to its design complexity. Moreover, the repair of this transmission usually doesn’t come cheap and not any repair shop can fix these complex units properly, but the many drivers who once had a chance to see these transmissions in action prefer to stick with it despite all problems. VAG doesn’t stay complacent and constantly improves the design and operating algorithms of DSG6 and DSG7, enhances the quality of mechatronics software, etc. Thus, it can be expected that the reliability and maintainability of these gear shifting solutions will gradually improve.

If you want to learn more about design of DSG transmissions and repair peculiarities click on the following link: https://go4trans.com/technical-transmission-general-articles/what-is-dsg-transmission-and-its-typical-repair-issues/

Multimode and FreeTronic: Controversial Robotic Gearboxes from Toyota

Wed, 05 Jun 2019 00:00:00 -0700

Multimode and FreeTronic: Controversial Robotic Gearboxes from Toyota

In the second half of the 90s, Toyota installed only traditional gear shifting technologies on its models – automatic and manual gearboxes, and they worked pretty well. But one day, marketing specialists of the Japanese Auto Giant noticed that automated (or robotic) manual gearboxes gave been gaining popularity in Europe. Toyota just needed to see how robotic solutions of other automakers worked in practice and to complement already known solutions with its advanced technologies. But Toyota decided to resort to the method of its own trails and errors, but something certainly went wrong. In this article, we’ll become familiar with FreeTronic and Multimode gearboxes, which are considered by many experts and car enthusiasts to be far from the most successful Toyota designs.

The FreeTronic system was the first experiment of Toyota engineers in the segment of automated (robotic) manual gearboxes. This solution was designed on the basis of a traditional manual unit, supplemented by an electric drive system. It operates in manual and automatic modes, the gear shifting is provided by 3 electric motors: one of them depresses the clutch, while 2 others engage required gears. The operation of the drives is controlled by the TCM unit, which processes signals from numerous sensors. From 2005 to 2009, this robotic gearbox was installed on Corolla, Yaris, Prius, and Aygo models.

1 – indicator,2 – ajar switch of the gearbox lever, 3 – drive, 4 - sensor 1-2, 5 – reverse sensor, 6 – neutral sensor, 7 – gearbox rotation sensor, 8 – clutch position sensor, 9 – electronic control unit

Engagement and disengagement of the FreeTronic clutch is performed by controlling the amount of fluid pressure that is applied to the clutch master cylinder. The gearbox is equipped with sensors, some of which monitor the actual position of the gear selector, while others measure the frequency of the input shaft rotation. The shift lever is equipped with ajar switches, which proactively inform the control unit on intensions of the driver to engage the gear shift lever. If there is any malfunction, the indicator starts blinking on the dashboard. The indicator also blinks when the driver shifts gears incorrectly. When a driver abruptly presses the gas pedal, the TCM unit takes it as a signal for acceleration and quickly downshifts. If the gas pedal is released, the system does not shift gears, but efficiently uses the brake power of the engine. The traction force remains stable to secure the possibility of re-acceleration.

The FreeTronic unit is equipped with the radial-piston-type pump with the system of electric drives. This pump maintains normal pressure in the membrane hydraulic accumulator. If the sensor detects any pressure drops, it activates the pump. ATF flows get redistributed by a slide (spool) valve with an electromagnet.

FreeTronic Transmission

When Toyota cars with the FreeTronic start moving, the control unit receives a corresponding signal. The same unit receives signals from the sensor that keeps track of the throttle position. Then the control unit forcibly reduces the pressure in the slide (spool) valve and engages the clutch – and as a result the car starts moving. Next, rotational speeds of the crankshaft and the input shaft start growing, the channel of the clutch master cylinder opens, and the clutch starts operating to the full extent.

To put it mildly, the first Free-Tronic models, are not very reliable. The electrics of the gearbox frequently displays false trouble codes, while such components as pressure sensors, slide valves, and hydraulic accumulator often get out of order. If the hydraulic accumulator fails, the electric pump starts working incorrectly, resulting in its damage and fluid leakages through seals. In addition, spare parts for this gear shifting unit are quite expensive. In many cases, the simplest solution to deal with all Free-Tronic issues is to replace it with a conventional manual gearbox. We can conclude that this Free-Tronic unit was a total failure and Toyota had to drop this technology.

Multimode

The FreeTronic solution was replaced by the Multimode gearbox (also known as MMT or M/M). This sequential manual gearbox is equipped with an electronically controlled clutch. This transmission was installed on numerous Toyota models in Europe, and should not be confused with Multimode Automatic Transmission, which is offered in the North American market by Toyota.

Common automatics ensure smooth driving characteristics, thanks to epicyclical gears, hydraulic clutches and a torque converter, while the MMT system does not have these features. In fact, the MMT is a usual 5-speed gearbox with an electronic control mechanism responsible for gear shifting and clutch operation. The negative experience with the FreeTronic solution forced Toyota engineers to exclude hydraulic drives/actuators from the Multimode design. Thus, to provide an efficient manual gearbox with automatic features to the automobile market, Toyota implemented 5 sensors and 3 electric motors in the Multimode design. It is worth mentioning that both robotic solutions designed by Toyota can operate in limp mode. If the TCM system detects any failures in the system, a warning lamp, indicating a problem, turns on.

There are three actuators; the shift and select actuators in the MMT, which move the selector rod in the same way as the “H” movement of a manual gearbox.

The clutch actuator in the MMT moves the clutch pushrod.

Despite all efforts of Toyota engineers, the Multimode system gained the reputation of a “dreadful gearbox”, because of numerous repair issues. In spite of the fact that the Multimode has the lower number of problematic spots than its predecessor, its reliability still leaves much to be desired. Repair specialists frequently had to replace TCMs, burnt clutch discs, and actuators during the Multimode repair.

One of the most dangerous issues for both Toyota gear shifting solutions is the clutch overheating. When the clutch in the Multimode gearbox overheats, the system gives an intermittent signal and the MMT warning lamp starts flashing. It often turns out to be the case in hot weather when cars equipped with the abovementioned gearboxes get stuck in traffic jams. But both gearboxes are equipped with a special mechanism, which forces N mode engagement to cool down the clutch mechanism during overheating.

Principle of operation of robotic Toyota transmissions

The clutch is always engaged before the engine start.

Start. After turning the key to the ignition position (the N gear is engaged), the control unit disengages the clutch and the engine can be started.
Starting off. When the 1-st gear or the reverse gear is engaged and the gas pedal is pressed, the control unit instantly receives the information about it by means of signals from sensors and issues a command to the slide valve to reduce pressure, leading to the clutch engagement and the car starts off. For smooth engagement of the clutch, the slide valve opens gradually, and its full engagement takes place after leveling speeds of the crankshaft and the input shaft of the gearbox. At this moment, the control unit gives the command to completely open the channel of the clutch master cylinder.
Gear shifting. When the gas pedal is released and the driver changes the position of the gear lever, the corresponding sensor reports about it to the TCM unit. The control unit gives the command to depress the clutch.
Stop. At the moment of brakes application, the gearbox input shaft starts rotating with a lower RPM rate and the control unit performs the clutch disengagement.
Sound buzzer. This mechanism gets engaged during inaccurate gear shifting operations: errors during downshifting, when the driver tries to start moving from a gear above the 3-rd, excessive load on the clutch, trying to start the engine when the gear is engaged, the driver’s door is open when the engine is running and the position of the gear selector lever corresponds to forward or backward driving (not the N gear).

Typical repair issues

Repair of electric components (TCM reflashing, replacement of brushes in electric motors, repair of circuit boards);
Repair of hydraulic and mechanical components (hydraulic cylinder, bearings, gears);
Repair of elements related to the gear selection mechanism (replacement of sensors, bearings, electric motor winding).

Toyota Corolla MMT Shift Actuator repair

The range of repair services also includes work on the clutch replacement with adjustment of the robotic gearbox, throttle cleaning, actuator testing. Competent services will delay the failure of FreeTronic and Multimode units, but it is hardly possible to avoid repair of these gearboxes when reaching mileages of 200 thousand kilometers.

Recommendations on these gearboxes from Toyota come down to proper maintenance and adherence to operating rules:

To avoid jolts when shifting gears, it is necessary to accelerate smoothly and to reduce speed a little before shifting gears;
Try not to move at low speeds when driving uphill, because the clutch slips and overheats;
When driving uphill, it is also advisable to shift gears manually and to downshift.

Key Facts you Need to Know about the Porsche PDK Transmission

Thu, 30 May 2019 00:00:00 -0700

Key Facts you Need to Know about the Porsche PDK Transmission

If you've ever considered Porsche models as an option when buying a car, you must have come across an unusual abbreviation PDK, when examining Porsche’s specifications. This advanced transmission solution, built in-house, ensures extremely fast gear shifting and found application in numerous Porsche models for a good reason. But what exactly is PDK and how does it work?

What Is a PDK Transmission?

PDK is an abbreviation for Porsche-Doppelkupplungsgetriebe, which can be rendered in English as Porsche double-clutch transmission. As you might have guessed, it’s Porsche’s version of a dual-clutch transmission (DCT) and actually its operational concept is mainly identical to other DCTs available on the market today.

Porsche representative tells about PDK transmission

In fact, PDK is a 7-speed solution developed by Porsche in collaboration with the German company ZF. This sophisticated solution operates in both manual and automatic modes and ensures very smooth gear shifting and lack of power losses.

Historical Background of PDK

The first developments of this transmission date back to the sixties, when the carmaker tried to unlock the potential of its promising technical solutions in motorsports. It took about two decades for Porsche engineers to develop the early PDK version, which debuted in the 956/962 racing program. This solution received many mixed reviews: despite its fast shifting performance, some drivers complained about issues with overcomplicated electronics and hydraulic units of the transmission. Moreover, the first PDK versions were significantly heavier than other transmission solutions used at that time, and the maximum weight reduction of car components has always been a priority in the world of auto racing. These challenges provided Porsche engineers with food for thought and they spent the following years on modification of this promising transmission technology and its adjustment for passenger cars, and subsequently their efforts paid off when in the 2000-s the company finally installed the long-expected transmission on its 997 and 911 models. The PDK was not the first dual-clutch solution on the market, but it gained popularity thanks to its durability and reliability in comparison with DSG solutions.

Design peculiarities and principle of operation.

Released in 2009, the PDK solution challenges the limits of operational characteristics and acceleration parameters by ensuring more rapid gear shifting than traditional transmissions. Moreover, this sophisticated mechanism doesn’t need clutch replacements and ensures more accurate starts from a standstill.

Porsche PDK transmission

So what is the secret of this transmission and why did it find application in numerous Porsche models?

In fact, the PDK transmission consists of two gearboxes combined in one housing. It is logical to assume that the presence of two gearboxes requires two clutches, thus Porsche engineers installed integrated two separate wet clutches operating in the oil bath. They ensure necessary lubrication of transmission components. This dual clutch alternately connects two gearboxes with the engine via two separate drive shafts. Shafts are based on the two-in-one principle. One shaft is hollow and the second shaft is located inside the first one.

In terms of design, one gearbox with its wet clutch is responsible for even gears (2, 4, 6) and an R gear, while the second gearbox controls the engagement of odd gears (1,3,5,7). The gear shifting process is based on the overlap principle, i.e. when the odd gear is engaged, the following even gear gets pre-selected. That is why dual clutch transmissions are also called preselective.

Learn more about PDK transmission operation

Thus, the engine power flow is constantly transmitted via one gearbox and one wet clutch, while another gearbox pre-selects the next gear. As a result, to shift to the following gear the PDK transmission has to lock one clutch and simultaneously unlock the other one. Therefore, the process of shifting from one gear to the next gear occurs within milliseconds.

The total number of gear in the PDK transmission is 7. Top speed is achieved on the 6-th gear, while the 7-th gear with a high gear range helps to reduce fuel consumption. The gear shifting can be implemented automatically or manually with the help of special paddle shifters.

Manual vs. PDK

Due to its complex design, the PDK transmission is 30 kg heavier than its manual 7-speed analog.

State-of-the-art technical solutions implemented in this transmission allowed achieving the following:

Unmatched gear shifting speed;
Improved fuel efficiency in comparison with classic automatics;
High smoothness of gear shifting.

When it comes to drawbacks of this transmission, it should be noted that this transmission is quite expensive and it is considered almost irreparable due to its structural complexity. If the PDK transmission gets out of order on a non-warranty car, then the owner will have to pay up to 1/3 of the cost of a new car for the new transmission unit and its installation. Similar to a conventional automatic transmission, the PDK unit has a traditional economy running mode(D) and a sport mode (S). When the sport mode gets engaged, the engine RPM aims to achieve high limit values, and the 7-th gear gets blocked. In the Sport Chrono Plus package, the PDK is completed with additional features “Launch Control” and “Performance Start”. To use the Launch Control function, it is necessary to depress the brake pedal, and press on the gas pedal. When the engine RPM reaches more than 3000 RPM, it is necessary to release the brake pedal and the car will accelerate abruptly from stop.

8-speed PDK for hybrids

8-speed hybrid PDK transmission

Nowadays, due to constant toughening of environmental restrictions, major automakers gradually shift to environment-friendly technologies investing significant financial resources to development of hybrid and electrical drivetrain components, and Porsche is not an exception. After a huge success of the 7-speed PDK model, Porsche engineers designed an 8-speed version for its Panamera model, which has hybrid as well as non-hybrid application. The new product incorporates the original system's swift gear shifting capacity with more compact design, a higher torque limit (737 ft-lbs) and an extra gear for the next-gen of cars and fuel economy.

The hybrid unit is embedded straight into the dual-clutch casing. The 8-speed solution affords 3 overdrive ratios for enhanced efficiency, and the Panamera reaches its maximum speed in 6-th gear. Both the 7-th and 8-th gears have a longer ratio for the purpose of keeping the RPM rate low at high speeds. This solution makes the Panamera both faster and more efficient than ever before.

PDK vs. Manual

In contrast to a manuals, the PDK solution ensures more rapid speed ups as well as greater operational flexibility. A driver can shift gears manually with the help of paddle-shifters and fully automatically when it is required to focus on the road. Owners of Porsche models equipped with the PDK gearbox also can enjoy the following benefits:

Swift gear shifting
Improved fuel economy
Better driving experience
High durability of the unit

Reliability

The PDK transmission is quite reliable in comparison with other dual-clutch transmissions, but the service life of this unit directly depends on regular maintenance servicing and compliance with operation rules specified by the automaker. Regular ATF changes are a must, if you want to avoid premature wear-out of costly transmission components. The best way to guarantee that the PDK transmission will not fail before its time is to monitor the ATF condition and never forget about regular maintenance services.

PDK Repair

The PDK is a sophisticated piece of machinery, but quite a pricy one. Therefore, to minimize potential financial losses related to the repair and maintenance of this gearbox, it is necessary to know when it’s a high time to visit the nearest repair shop. In most cases, Porsche drivers start having issues with the PDK unit because of insufficient fluid level. Thus, it is required to check the ATF condition timely and to change it when you notice any signs of fluid contamination. If you notice a puddle of fluid under your car, it’s probably leaking. Other common signs of malfunction you have to keep in mind are the following:

Illuminated warning lights
Unusual smells
Delays in gear shifting
Uncommon grinding noises

All in all, this advanced transmission has no significant weaknesses, except its high price and issues with repair. This transmission allows owners of Porsches to realize the full potential of the car’s performance capacity and to enjoy the process of driving.

Why ZF’s 8-speed Automatics are so Popular Among Major Carmakers?

Mon, 06 May 2019 00:00:00 -0700

Why ZF’s 8-speed Automatics are so Popular Among Major Carmakers?

Despite the fact that manual transmissions are simple, reliable, and easy to maintain, today it is clear that they are technically outdated, and the manuals are gradually being replaced by automatic transmissions. But it must be recognized that automatics are also not perfect in terms of reliability. However, there is a family of automatic transmissions, which surprises even ardent admirers of manual transmissions by its reliability. We are talking about the ZF8HP family designed and manufactured by the German company ZF Friedrichshafen.

The first version automatic transmission of this legendary family was developed in 2008 and was successfully tested on the BMW 7-series. Then this successful solution found application on other cars.

The 8HP transmission family includes numerous modifications, and each of these modifications has specific technical characteristics:

8HP45
8HP50
8HP55
8HP65
8HP70
8HP75
8HP90
8HP95

The ZF8HP family includes 8-speed automatic transmissions designed for installation on cars with a longitudinal engine positioning. When working on the 8HP family, ZF engineers wanted to design more fuel-efficient transmission solutions in comparison with its predecessor ZF6HP, and they managed to do it brilliantly. The fuel consumption of cars equipped with ZF8HP transmissions was reduced on average by 12-14% thanks to the use of 4 planetary gears instead of traditional external gears. In addition, the German engineers managed to reduce the gearshift time to 200 milliseconds and made it possible to shift gears in non-sequential order. It can be said that ZF specialists managed to develop a universal transmission solution, which is more efficient and lightweight than its predecessor, but has the same dimensions as ZF6HP transmissions.

Design Peculiarities

In terms of design, the ZF8HP family is an upgraded modification of ZF 6HP. Fuel efficiency and dynamic qualities of these transmissions significantly exceeded those of their predecessor. The structure of the ZF8HP transmission includes 3 clutch packages and 2 brake drums. The planetary gear set (there are 2 of them) was specifically designed for this transmission family. As a result, engineers managed to achieve the maximum transmission of torque at low speeds. The gear shifting is performed without losses of power, ensuring such a smooth gear shifting that it can be easily compared to DCT or CVT transmissions.

Cross-section of the ZF 8-speed automatic transmission – 8HP45

Compared to ZF6HP transmissions, solenoids have also been updated; in the newer design they transmit torque quite smoothly and intensively starting from the 1-st gear. The operation of ZF8HP transmissions is performed by means of the mechatronics unit.

The fuel consumption was also improved by the implementation of so-called “torque converter disconnection”: when the car stops the torque converter gets disconnected from the transmission by means of the clutch.

Why 8 speeds?

It was once believed that automatic transmissions needed no more than 3 or 4 gears. Nowadays, automatic transmissions have 8 or even 9-10 gears to ensure higher performance rates and to achieve better fuel economy, resulting in reduction of CO2 emissions.

If the transmission has many gears, the car engine operates with optimal RPM rates required for a particular situation, rather than operating with increased RPM rates when it is not necessary. It helps to reduce fuel consumption and unwanted emissions.

For this reason, ZF developed its legendary 8HP transmission family to replace its equally popular 6HP transmissions. In 2014, ZF engineers came up with a new modified 8-speed transmission version, which allowed increasing the fuel efficiency even further.

Why ZF’s 8-speed automatics are still so popular?

Currently, approximately 20 carmakers (including Audi, Chrysler, Jeep, Dodge, Jaguar, Maserati, Alfa Romeo, Land Rover, Bentley, Aston Martin and even Rolls-Royce) equip their cars with different 8HP modifications. What’s the secret of their success?

The following cars are equipped with the 8HP automatics:

Maserati Ghibli

Rolls-Royce Phantom

The thing is that, unlike other transmission solutions, 8-speed transmissions from ZF can be installed on vehicles with different types of drives, including 4WD. This family of transmissions can be installed not only on gasoline-powered cars, but also can easily integrated into diesel vehicles as well as hybrid models. Moreover, ZF’s 8-speed automatics have a wide range of output powers.

The design of these transmissions allows carmakers to position engines not transversally, but longitudinally. These automatics are controlled by unique software, which can be easily adjusted for a specific model.

Great video on the subject from Engineering Explained

It should also be borne in mind that the family of ZF’s 8-speed automatics includes many modifications, which can be applied for a wide range of different car models with different torque and power qualities. Therefore, automakers can buy such a transmission from ZF, which would be ideal for a particular car model, and then, adopt the software to achieve required performance parameters. Thanks to such flexibility of 8-speed automatic transmissions, ZF helps car makers to save significant financial resources which would be needed to develop their own transmission solutions.

Repair and maintenance

Despite the fact that ZF’s 8-speed automatics are famous for their phenomenal reliability and outstanding technical characteristics, drivers should not forget about rules of automatic transmission operation and its maintenance.

It is not a secret that ZF8HP transmissions can operate under heavy loads, but before aggressive driving it is necessary to warm-up the transmission. These transmissions are very sensitive to contaminated ATF, thus it is necessary to regularly check the transmission fluid condition and change it, if necessary. The ATF change in 8HP transmissions is performed together with the replacement of the pan and the filter every 80,000 kilometers (or every 60,000 kilometers with aggressive driving style).

In addition, it is necessary to test the torque converter for wear of friction plates of the torque converter lock-up every 100,000 kilometers, if the transmission operates under severe conditions.

All in all, it should come as no surprise that the 8HP automatic transmission family is still popular among leading carmakers and that these automatics compete in gear shifting quality with dual-clutch and CVT transmissions. No matter whether it is a big American truck (RAM) or a luxury car (Rolls-Royce Phantom), ZF’s 8-speed automatics will ensure smooth and rapid gear shifting.

What to Keep in Mind When Assembling the Clutch

Sat, 04 May 2019 00:00:00 -0700

What to Keep in Mind When Assembling the Clutch

Clutch assembly is not an easy task that requires time and perseverance. To avoid frequently needless and expensive replacement of the whole unit, prior estimation is a must. In such cases, ZF Aftermarket is eager to share its solid experience in the transmission repair with the repair shops, helping to prevent errors specifically related to clutch plate mounting.

The clutch is a connecting link between the engine and gearbox – and one of the most wear-resisting elements. The clutch can get out of order for many reasons. For instance, the clutch is frequently exposed to high loads due to towing/driving with a trailer or a defected engine control unit. However, if the clutch unit does not operate properly that does not necessarily mean that you are instantly doomed to pay for replacement of the whole unit. ZF Aftermarket experts recommend repair shop technicians to carefully inspect the adjacent elements in case of clutch malfunctions – including the clutch engagement and the seals of the engine, flywheel, and gearbox. Repair professionals often use the Sachs clutch kit in this instance as it contains all the required components for a fast and safe repair.

Sachs clutch kit

Clutch examination before assembly

The clutch must be quite durable and heat-tolerant, because the operation under severe loads may cause abrasive wear. Sachs ZF specialists recommend using Sachs clutch plates which conform to top quality standards and are also tested for clearance.

However, nothing is perfect and it would be reasonable to check the state of the package and the new clutch before installing it, as it may have been broken during shipping or because of incorrect handling. To be certain that the new part is in good running order ensure that the lateral run-out of the clutch plate is limited to 0.5 mm. If the allowed value is exceeded, this issue can be solved with the help of a straightening fork, which is included in the Sachs lateral run-out tester.

Mounting position and clutch centering

The correct positioning of the clutch unit during installation is a key to successful repair service. The clutch misplacement may lead to the breakdown of the clutch itself, its hub spline, clutch toggle lever, or even the gearbox. The installation instructions can be commonly found on the component side. Another simple solution is to compare the new clutch with the old one before mounting.

The new clutch must be accurately centered to avoid any problems with the hub spline. It is crucial to comply with tolerance limits between the gearbox input shaft and the hub spline, because even the slightest incorrectness exceeding the allowable limits (only a few hundredths of a millimeter) during installation of the input shaft can later prevent the mobility needed for the clutch release. The hub spline must freely slide onto the gearbox shaft.

Hub spline lubrication (greasing)

ZF experts advise lubricating the hub spline with Sachs advanced lubricating materials. Thanks to its viscosity and heat endurance the lubricant sticks to the spline while operating without spreading. To avoid clutch judder when the clutch is later released, surpluses of lubricating materials must always be eliminated, and the clutch linings must be kept clean .

Products in OEM quality

To ensure enhanced reliability and running characteristics, ZF specialists encourage technicians of repair shops to use top-quality spare parts in maintenance and repair of the powertrain components. Therefore, it is reasonable to pay attention Sachs clutch products, manufactured with the help of quality materials and thoroughly tested in accordance with the highest standards. Sachs repair kits are ideal solutions for professional repair shops, as they contain everything you need to provide top-quality repair services.