Mercedes-Benz 722.3

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.

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.