Transmission Diagnostics & Repair

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 gearsTransmission TypeDriveTorque (Nm)ATF (full capacity) LATF (change) LATF type5ATFWD3307,13,5Type 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?BrandModelYearTypeEngineChevrolet/GMEQUINOX04-095 SP F/4WDV6 3.4LOpel / VauxhallANTARA06-165 SP F/4WDL4 2.0L 2.4L V6 3.2LOpel / VauxhallSIGNUM03-085 SP F/4WDL4 2.2L V6 3.0L 3.2LOpel / VauxhallVECTRA02-095 SP F/4WDL4 2.2L V6 3.0L 3.2LPontiacTORRENT04-095 SP F/4WDV6 3.4LSaturnION03-045 SP FWDL4 2.2LSaturnVUE02-035 SP F/4WDV6 3.0LSuzukiXL-704-085 SP F/4WDV6 3.6L How to repair this transmission (Videos)AW55-51SN / RE5F22A Teardown InspectionAW55-51SN / RE5F22A Solenoid RepairAW55-51SN / RE5F22A Solenoid Repair PART 2AW55 Solenoid Adjustment, Diagnosis and Repair AW-55SN Linear Solenoid RepairAW55-51SN / RE5F22A Transmission Instruction manuals and useful linksLink typeSourceDescriptionpdfSonnaxValve Body Layout AW5550SNvideoSonnaxAW 55-50/51SN Solenoid Bracket Identification & InstallationwebSonnaxAW 55-50/51SN Pressure Tap LocationswebSonnaxAW 55-50 Differences Between Manufacturers Part 2webSonnaxAW 55-50 Differences Between Manufacturers Part 1

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 gearsTransmission TypeDriveTorque (Nm)ATF (full capacity) LATF (change) LATF type4ATRWD25012,56Type 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?BrandModelYearTypeEngineOpel / VauxhallASTRA00-044 SP FWDL4 2.0L 2.2LOpel / VauxhallVECTRA00-024 SP FWDL4 1.8L 2.0L 2.2L V6 2.5L 2.6LOpel / VauxhallZAFIRA99-144 SP FWDL4 2.0L 2.2LSuzukiSX406-124 SP FWDL4 2.0L

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 gearsTransmission TypeDriveTorque (Nm)ATF (full capacity) LATF (change) LATF type8ATRWD/AWD50096BMW 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?BrandModelYearTypeEngineAlfa-Romeo169168 SP R/4WDL4 2.0L 2.2LAlfa-RomeoGIULIA15-168 SP R/4WDL4 1.4L 2.0L 2.2L V6 3.0LAudiQ710-118 SP R/4WDV6 3.6LBMW1-SERIES11-168 SP R/4WDL4 1.6L 2.0L L6 3.0LBMW2-SERIES13-168 SP R/4WDL4 2.0L L6 3.0LBMW3-SERIES11-168 SP R/4WDL4 1.6L 2.0L L6 3.0LBMW3-SERIES GT13-168 SP R/4WDL4 2.0L L6 3.0LBMW4-SERIES13-168 SP R/4WDL4 2.0L L6 3.0LBMW4-SERIES GRAN COUPE14-168 SP R/4WDL4 2.0L L6 3.0LBMW5-SERIES10-168 SP R/4WDL4 1.6L 2.0L L6 2.5L 3.0LBMW5-SERIES GT09-168 SP R/4WDL4 2.0L L6 3.0LBMW6-SERIES GRAN COUPE12-168 SP RWDL6 3.0LBMW7-SERIES10-158 SP R/4WDL6 3.0LBMWX111-168 SP R/4WDL4 1.6L 2.0L L6 3.0LBMWX310-168 SP R/4WDL4 1.6L 2.0L L6 3.0LBMWX414-168 SP 4WDL4 2.0LBMWX513-168 SP R/4WDL4 2.0L L6 3.0LBMWX610-148 SP 4WDL6 3.0LBMWZ411-168 SP RWDL4 2.0LChrysler30011-168 SP R/4WDV6 3.0L 3.6LDodgeCHALLENGER14-168 SP RWDV6 3.6L V8 5.7L 6.4LDodgeCHARGER12-168 SP R/4WDV6 3.6LDodgeDURANGO12-168 SP R/4WDV6 3.6LDodgePICKUP/RAM 150012-168 SP R/4WDV6 3.6LJaguarF-TYPE15-168 SP RWDL4 2.0LJaguarXE15-168 SP R/4WDL4 2.0L V6 3.0L V8 5.0LJaguarXF15-168 SP RWDL4 2.0LJEEPGRAND CHEROKEE11-168 SP R/4WDV6 3.0L 3.6LJEEPWRANGLER UNLIMITED15-168 SP 4WDV6 3.6LLanciaTHESIS118 SP R/4WDL4 1.8L L5 2.5L V6 3.6LLand-RoverDISCOVERY(LR3)10-118 SP R/4WDL6 3.7LVolkswagenAMAROK12-168 SP R/4WDL4 2.0L V6 3.6L How to repair this transmission (Videos)Components and operationValve BodyZF8HP70 Main CaseZF8HP70 Pump RemovalATSG Transmission TipRay's Garage- ZF8HP70 Unit DisassemblyRay's Garage Tech Tip: ZF8HP55 Instruction manuals and useful linksLink typeSourceDescriptionpdfSonnaxValve Body Layout ZF8HP45, ZF8HP70pdfSonnaxValve Body Layout ZF8HP55pdfSonnaxVacuum test ZF8HP45, ZF8HP70