722.6 Overhaul Kit 1996-2011, new and ready to install. Fits the 722.6. Ships fast from the USA.
Mercedes C-, E-, S- and ML-class owners, Sprinter drivers, and anyone running a Chrysler 300, Dodge Charger or Magnum, or Jeep Grand Cherokee with the NAG1 five-speed usually land here for the same reasons: a puddle under the transmission, a shift into Drive that takes a second too long when the car is cold, or a unit that has been opened up and now needs to go back together dry. This is a new seal and gasket overhaul kit for 1996-2011 722.6 / NAG1 transmissions, manufacturer kit number K56900GX. It carries the gaskets, lip seals, O-rings, sealing rings and small rubber parts for a complete teardown and reseal. It does not include friction plates, steel plates or a filter, so it is the right kit when your clutch packs measure good, or when you are buying those separately.
The 722.6 is a fully electronic five-speed: the conductor plate solenoids meter oil through the valve body, and that oil travels down drilled passages, across rotating shafts and into each clutch and brake piston. Every one of those handoffs depends on a seal. Teflon or cast sealing rings ride on the shafts, molded lip seals and O-rings ring each piston, and gaskets close the case, pump and pan. Heat cycles harden the rubber and wear the ring grooves, and pressure that should apply a clutch leaks back to the sump instead. The 722.6 also has a well-documented converter-feed weak spot: Transmission Digest describes how a leak at the input shaft sealing area robs the converter and cooler circuits, producing lockup shudder and low or no cooler flow. Fresh sealing rings and correct shaft-to-ring fit are part of curing that, which is why rebuilders treat the seal kit as mandatory on any open 722.6.
Start with level and condition. Mercedes has 722.6 fluid checked hot with the engine running, and most cars have no dipstick in the tube, so a slow external leak can run the level low before anyone notices. Clean the outside of the case and find the leak source before buying anything: a leak at the round 13-pin case connector is the connector adapter, which is serviced from the pan side without a teardown and comes in our conductor plate, adapter and filter kit. If the fluid is burnt or full of friction material, the packs are gone and a master kit is the better buy. Our 722.6 common problems guide walks through separating valve body wear (2-3 and 4-5 flare) from seal leakage, and the pressure control solenoid guide covers the electrical faults that mimic low pressure.
This kit is listed for 722.6 and NAG1 transmissions from 1996 through 2011, which spans the gasoline and diesel Mercedes applications and the Chrysler, Dodge and Jeep NAG1 cars and SUVs of those years. The 722.6 was built in a light-duty W5A 330 core and a heavy-duty W5A 580 core, and parts are not universal between them, so match the transmission ID plate on the case and the kit number K56900GX against your unit, or send us your year and VIN and we will check it before it ships. If you own a 2012-or-later NAG1, look at the 1996-2018 version of this kit instead. Every 722.6 part we carry is on the 722.6 / 722.9 collection page.
| Fits | 722.6 1996-2011 |
| Part type | Overhaul Kit |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. Kit K56900GX is the soft-parts set: gaskets, lip seals, O-rings, sealing rings and small rubber parts. Frictions, steels and the filter are separate. If your packs are worn, the master overhaul kit with frictions and steels is the better buy.
The kit is listed for 722.6 and NAG1 units from 1996 to 2011, which covers those Chrysler, Dodge and Jeep applications in that window. Because the W5A 330 and W5A 580 cores differ, send us your year and VIN or the case ID plate number and we will confirm.
You can, but a full overhaul is not required for that leak. The case connector adapter is reached by dropping the pan, and our conductor plate, adapter and filter kit covers that repair in the car.
Use an MB 236.14-approved ATF for most 722.6 units, or the later spec your vehicle calls for. Mercedes' 2013 fluid bulletin warns against mixing 236.14, 236.15 and 236.16 oils, so drain fully before switching.
Lockup shudder on the 722.6 is often a converter feed leak at the input shaft sealing area, which drops converter and cooler oil flow. Fresh sealing rings and checking the shaft fit during an overhaul address it; a fluid change alone will not.
