Reseal kit for the Mercedes 722.3 four-speed automatic, 1981-1996 gas and diesel, with every gasket, O-ring, lip seal and metal-clad seal.
Older Mercedes-Benz sedans, coupes and wagons with the four-speed automatic all reach the same point: ATF drips from the bellhousing, the rear seal weeps, and the 1-2 shift turns slow and soft as the rubber inside hardens. This kit is the reseal set for the 722.3, which Mercedes coded W4A 040, covering 1981 through 1996 units behind both gas and diesel engines, including the 617 and 603 diesel cars. It is part number K68900ADA from Tri Component, made in the USA, and it holds the paper gaskets, O-rings, rubber lip seals, metal-clad seals and sealing rings needed to close the transmission back up after a teardown.
The 722.3 is the heavy-duty member of Mercedes' third-generation automatic family, rated at 40 kp-m, about 392 Nm, and built with three planetary gearsets, two clutches and three brakes. Shift timing and feel come from hydraulics: a governor, a throttle linkage and a vacuum modulator tell the valve body how hard to apply each element. With so little electronic help, every seal matters. Oil from the pump reaches each clutch and brake piston through sealing rings on the supports, and the piston lip seals have to hold that pressure while the pack applies. When those parts harden, apply pressure bleeds away, shifts stretch out, and the plates start to slip. The kit replaces every one of those seals plus the case, pump and pan gaskets.
Clean the underside and find the true leak source first. A front pump seal leak shows wet ATF at the bottom of the bellhousing; an engine oil leak at the rear main looks darker and smells different. For shift complaints, rule out the vacuum side before a teardown. A 1994 technical bulletin covering the 722.3, 722.4 and 722.5 explains that the rubber cap on the modulator is part of the vacuum system, and a cracked or loose cap causes harsh or erratic shifts. With a hand vacuum pump on the hose fitting, the cap and modulator must hold at least 14 inches. Check the fluid hot, the vacuum line and the throttle linkage. If the car is a 1996-on model, it most likely has the electronic five-speed instead; our 722.6 common problems guide covers that unit.
This kit is listed for the Mercedes-Benz 722.3 / W4A 040 four-speed automatic, 1981-1996, gas and diesel. The lighter 722.4 four-speed looks similar and was used in many smaller-engined cars, and the 722.5 adds a separate fifth-gear housing at the back, so read the type number stamped on the case before you order. If you have the five-speed version, the 722.5 overhaul kit is the match. Not sure? Send us the year and VIN. Browse the rest of the family on our 722 transmission page.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is a reseal kit with gaskets, O-rings, lip seals, metal-clad seals and sealing rings. Frictions, steels, the band and bushings are sold separately.
It is listed for the 722.3 / W4A 040 only. The 722.4 and 722.5 are related but use their own kits, so check the type number on the case before ordering.
If the delay comes from hardened piston seals, yes. First check the vacuum modulator and its rubber cap, which should hold at least 14 inches of vacuum, and confirm the fluid level hot.
The manufacturer part number is K68900ADA, made in the USA by Tri Component.
The front seal can be changed with the transmission out of the car, but if the other seals are just as old, the leaks usually move to the next weak point. That is why this kit includes every seal.
