Overhaul set with frictions, steels, gaskets and seals for the Mercedes 722.4 four-speed automatic in the 190, 300 and early C-Class.
The 722.4 is the light-duty four-speed automatic Mercedes-Benz used behind its four-, five- and smaller six-cylinder engines, found in the 190E and 190D, the W124 300-series cars and the first C-Class. Owners searching for a fix usually describe the same thing: a long pause before drive or reverse engages on a cold morning, a slip or flare on the 1-2 shift, and fluid that smells burnt. This kit puts the overhaul gasket and seal set, the friction plate set and the steel plate set in one box, so a worn unit can be fully resealed and every pack renewed in a single teardown.
Mercedes called this transmission the W4A 020, a four-speed rated for 20 kp-m, roughly 196 N-m or 145 lb-ft of input torque. It entered production in 1982 and was built until mid-1996. First gear is deeper than in the heavier 722.3 (4.25:1 against roughly 3.7 to 3.9:1), which suits the smaller engines. It has no converter lock-up and is controlled hydraulically: a governor reads road speed, a vacuum modulator reads engine load, and a throttle linkage sets kickdown. Each gear is made by applying clutch and brake packs through pistons sealed with rubber lip seals. After many years those seals harden and bleed apply pressure, and the plates glaze. This kit replaces both halves of that problem: new seals so the pistons hold, new frictions and steels so the packs grip.
Check the inexpensive parts first, because on these cars they often cause what feels like a failed transmission. A 1994 technical bulletin for the 722.3, 722.4 and 722.5 notes that the rubber cap on the vacuum modulator is part of the vacuum circuit; if it is cracked, loose or missing, shifts become harsh or erratic. A hand vacuum pump on the hose fitting should show the cap and modulator holding at least 14 inches. Check the hot fluid level, the vacuum line to the intake, and the throttle linkage. Late engagement and slip that remain with clean vacuum and correct fluid mean worn packs or hard seals. For cars built after 1996, which moved to the electronic five-speed, see our 722.6 C-Class common problems guide and our 722.6 rebuild cost guide.
Listed fitment: Mercedes-Benz 190 (1990-1993) with the 2.3L four or 2.6L six; 300 (1991-1993) with the 2.5L five-cylinder or the 2.6L and 3.0L sixes; and C-Class (1994-1996) with the 2.2L four or the 2.8L and 3.6L sixes, all with the four-speed automatic. Be careful with the six-cylinder cars: the heavier 722.3 was also used in W124 and W202 models of these years and looks similar on the bench, but its clutch stack is different. Read the number stamped on the case before you order, or send us the year and VIN. All of our Mercedes parts are on the 722 transmission page.
If the pump is worn, the 722.4 pump replaces it, and a sticking or worn valve body can be swapped with the 722.4 valve body while the unit is out. If your case reads 722.3, use the 722.3 master rebuild kit instead.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. The 1990-1993 190 with the 2.3L four or 2.6L six is on the listed fitment, provided the case number reads 722.4.
Read the number stamped on the transmission case or the identification tag. The two look similar, and some six-cylinder W124 and W202 cars used the heavier 722.3, which takes a different clutch stack.
The overhaul gasket and seal set, a friction plate set and a steel plate set. It does not include the pump, valve body, torque converter or hard parts.
Hardened piston lip seals leak apply pressure until the fluid warms up. A low fluid level or a vacuum leak at the modulator can add to it, so check those first. If it persists, the seals and frictions in this kit are the fix.
Test it. A 1994 bulletin says the modulator cap and modulator should hold at least 14 inches of vacuum. A leaking modulator lowers line pressure and can make fresh frictions slip.
