TouchShift: features, advantages & disadvantages

TouchShift: features, advantages & disadvantages

TouchShift is a manual gear shifting function in automatic transmissions installed on Mercedes-Benz models. It debuted in the late 1990s. It allows the driver to control the gear shifting process, which is convenient when driving uphill, downhill, accelerating, manoeuvring, and starting on slippery surfaces.

How the TouchShift works

The TouchShift function is available for classic automatic transmissions with a hydraulic torque converter and planetary gear sets. It functions thanks to specialised firmware that makes it possible to lock up the gear selected by the driver. With a short push of the gear lever from the “D” position towards the “D+” or “D-” direction, the mode can be switched to manual. The activated mode and selected speed will then be displayed on the instrument panel screen. The system won’t shift to a lower gear when driving at a very high speed, in order to avoid engine damage.

Popular transmissions with the TouchShift function

Gearbox code Number of speeds Max engine capacity, L Max torque, N·m Car layout Production start Mercedes-Benz model applications
722.6 5 3.5 350 RWD, AWD 1995 S-Class W140; C-Class W202; E-Class W210; C-Class W203; S-Class W221; C-Class W204; E-Class W212; E-Class W211; S-Class W220; M-Class W163
722.7 5 1.9 205 FWD 1998 A-Class W168; Vaneo W414
722.9 7 6.3 850 RWD, AWD 2003 S-Class W220; C-Class W205; E-Class W212; C-Class W204; E-Class W211; M-Class W164; S-Class W221; M-Class W166

Common malfunctions of transmissions with the TouchShift function

MalfunctionsTransmissions
The bush located between the transmission shafts has a short lifespan.722.6
The one-way clutch is prone to breaking.722.6
The transmission solenoids get soiled fast.722.6
The torque converter lockup solenoid breaks down prematurely.722.6
The conductor plate quickly becomes unserviceable.722.6; 722.7
The clutch drum often breaks down.722.7
The conductor plate quickly breaks down.722.9
The transmission case gets damaged due to excessive vibrations.722.9
The servo module sometimes breaks down.722.9

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