Mercedes-Benz 722.4 4-Speed Automatic Transmission · Mercedes-Benz · Expert rebuild service since 1987. Lifetime warranty. Free diagnostic.
1986–1995 Mercedes-Benz W124 (300E/400E/500E), 1991–1999 Mercedes-Benz W140 (S-Class V8), 1993–1999 Mercedes-Benz W202 (C280/C36 AMG early)
| Configuration | 4-speed automatic RWD transmission (updated hydraulic control) |
|---|---|
| Gear Ratios | 1st 3.87:1 · 2nd 2.25:1 · 3rd 1.44:1 · 4th 1.00:1 · Rev 5.59:1 |
| Fluid Type | Dexron III ATF |
| Fluid Capacity | 7.5 qts total, 3.5 qts service refill |
The kickdown switch (WOT switch) fails, preventing the transmission from downshifting to lower gear under full throttle.
Symptoms: No kickdown response under hard acceleration, vehicle stays in current gear even at full throttle
The conductor plate — which houses the speed sensor and solenoid connections — corrodes and cracks, causing intermittent DTCs and shift quality issues.
Symptoms: P0717 or P0722 DTCs, erratic shift quality, speed sensor faults on early EIS cars
The hydraulic valve body bores wear with age, causing pressure leakdown and inconsistent shift feel.
Symptoms: Soft or harsh variable shifts, engagement delay, converter slip at cruise
722.4 rebuild replaces conductor plate, valve body solenoids, all clutch packs, and all seals. Kickdown switch is tested and replaced if faulty. Torque converter is rebuilt. Dexron III used.
Dexron III ATF every 40,000 miles. The conductor plate is a common failure item — inspect it whenever servicing this unit. W124 500E owners (rare and collectible) should rebuild early to preserve the vehicle.
W124 (300E through 500E), W140 S-Class V8, and early W202 C-Class with 4-speed automatic from 1986–1999.
The conductor plate is a printed circuit board that connects the solenoids and speed sensor to the external wiring harness. Corrosion causes multiple symptoms.
A full rebuild ranges $1,700–$2,200 at Chicago Transmission.
Dexron III ATF.
Yes — it's a robust transmission when maintained. Most failures are conductor plate or modulator-related rather than internal mechanical.
Free diagnostic, written estimate, lifetime warranty. Chicago's 722.4 rebuild specialists since 1987.
