The Mercedes 722.3 4-speed automatic transmission, also known as the 4G-Tronic, was produced by Mercedes from 1979 to 2000 and was installed in rear- and all-wheel-drive models with engines up to 6.0 liters. There are four versions of this transmission: the W4A028, W4A040, W4A040 II, and the extra-powerful W4A055. The 4G-Tronic family also includes: 722.4.
Specifications
| Type | automatic transmission |
| Number of gears | 4 |
| Type of drive | rear / all wheel |
| Engine volume, l | up to 6.0 |
| Torque output, Nm | up to 580 |
| Recommended oil | ATF MB 236.6 |
| Oil capacity, liter | 7.3 8.6 Geländewagen and high-performance models for the USA |
| Partial replacement, liter | 6.2 7.7 Geländewagen and high-performance models for the USA |
| Maintenance | every 60 000 km |
| Gearbox lifespan, km | ~500 000 km |
| Weight, kg | 73 |
In September 1979, a new 4-speed automatic transmission was added to the W126 executive sedan. It was a conventional hydromechanical automatic with a classic governor, meaning it lacked electronics, a torque converter lockup, and other modern trappings. There were four versions of this transmission: most Mercedes models were equipped with the W4A040 modification and the updated W4A040 II (introduced in 1985). Geländewagen SUVs and Sprinter minibuses were equipped with their own version of the W4A028 transmission, while high-performance models like the S600 sedan were equipped with a reinforced version, the W4A055.
Gear ratios Mercedes 722.3
Using the example of a 1993 Mercedes S 400 with a 4.2 liter engine:
| Main | 2.65 |
| 1st | 3.871 |
| 2nd | 2.247 |
| 3rd | 1.436 |
| 4th | 1.000 |
| Reverse | 5.586 |
Using
The transmission was installed on:
- Mercedes CL-Class C126 in 1981 – 1991; CL-Class C140 in 1992 – 1995;
- Mercedes E-Class W123 in 1980 – 1986; E-Class W124 in 1984 – 1997; E-Class W210 in 1995 – 1996;
- Mercedes G-Class W463 in 1990 – 1995;
- Mercedes S-Class W126 in 1979 – 1991; S-Class W140 in 1991 – 1996;
- Mercedes SL-Class R107 in 1980 – 1989; SL-Class R129 in 1989 – 1995;
- Mercedes Sprinter W901 in 1995 – 2000;
- SsangYong Korando 2 (K100) in 1996 – 1998;
- SsangYong Musso 1 (Y100) in 1993 – 1998.
Disadvantages of the Mercedes 722.3 gearbox
- This is a simple, highly reliable automatic transmission with a long service life, but at high mileage, wear debris from the clutches can clog the valve body. If the transmission hasn’t reached its service life, a simple flush may be sufficient.
- Also, at very high mileage, the vacuum modulator diaphragm or the vacuum supply line can crack, causing the transmission to shift sluggishly. A broken kickdown cable is often the culprit behind automatic transmission malfunction.
- Almost all remaining complaints on specialized forums are related to oil leaks. It’s worth noting cases of reverse gear replacement where the springs weakened and popped out.
