Mercedes 722.4 (W4A020) is a 4-speed automatic transmission with a manual gear selection mode. This gearbox was installed on some Mercedes-Benz models between 1981 and 1996. It is also known as the 4G-Tronic and has a reputation for being reliable.
How it works
The Mercedes 722.4 (W4A020) is a traditional automatic gearbox with a hydraulic torque converter (without lock-up) and planetary gear sets. Driving modes are selected by moving the gear lever to the corresponding position. In the “D” mode, all 4 gears are used. This mode is recommended for normal driving conditions. When the lever is in the “3” position, the gear range is limited to the first three speeds, which is ideal for long, gradual ascents and descents. The “2” mode includes only the 1st and 2nd speeds, which helps the vehicle cope with steep hills efficiently, especially when towing a trailer. The “B” mode allows engine braking.
Technical characteristics of the Mercedes 722.4 (W4A020)
|Gearbox code||Number of gears||Max engine torque, N·m||Max engine capacity, L||Car layout||Engine arrangement||Model applications|
|722.4||4||250||3.0||RWD||Longitudinal||E-Class W123; S-Class W126; C-Class W202; E-Class W124|
Common malfunctions of the Mercedes 722.4 (W4A020)
- The hydraulic valve body channels get clogged over time.
- The vacuum modulator sometimes fails.
- In some cases, the clutch pack springs break.
- The Teflon O-rings of the hydraulic valve body and the transmission pump seal often start leaking.