Transmission Diagnostics & Repair

Common Transmission Problems, Diagnostics and Repair Procedures

Technical guides on automatic transmission diagnostics, repair procedures, component testing, failure analysis, and service methods for transmission specialists, rebuilders, parts suppliers, and repair professionals.

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 gearsTransmission TypeDriveTorque (Nm)ATF (full capacity) LATF (change) LATF type6ATFWD/AWD3807,54SsangYong 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
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 gearsTransmission TypeDriveTorque (Nm)ATF (full capacity) LATF (change) LATF type3ATRWD9,84,2ATF 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.
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 gearsTransmission TypeDriveTorque (Nm)ATF (full capacity) LATF (change) LATF type∞CVTFWD1507,64,3Esso 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 1Belt replacement pt2Mini Cooper CVT overviewZF VT1 CVT Transmission Stepper MotorRover - Service Insight - VT-1 Automatic TransmissionMini CVT transmission teardownMini CVT teardown test clipMini Cooper cvt adaptation
While manual gearboxes utilize the clutch to shift speeds, automatic transmissions make use of a sophisticated hydraulic system for shifting, and the transmission solenoid is especially important for this process.