722.6 Clutch Module 1998, new and ready to install. Fits the 722.6. Ships fast from the USA.
A 1998 model year 722.6 is the one most likely to confuse a rebuilder, because that is when the K3 clutch pack went to a thicker friction while the K2 kept its large inside diameter. This new friction module, reference R78119B (interchanges with Raybestos FRMMERCE04), is the set built for that combination: large-ID K2 plus thick K3. If your late-1990s Mercedes C 280, E 320, ML 320, SL or S-Class came apart with glazed or burnt frictions, and the K3 plates you pulled out are the thick style, this is the module to stack back in.
The 722.6 uses three clutches (K1, K2 and K3), three brakes and two freewheels to make five forward gears and reverse, with no bands at all. K3 is one of the packs that has to hand over cleanly to the next element on a shift, so its frictions see heat on every gear change that uses it. A thicker friction gives the pack more lining to absorb that heat, but it also changes the stack height. Put thin K3 frictions into a drum designed for the thick ones and the clearance opens up, which shows up as a slow, flaring shift; put thick ones into an early drum and the pack can be too tight to release fully. That is why we list this module separately from the 1996-2000 version even though the years overlap.
Before ordering plates, rule out the 722.6 faults that imitate clutch wear. The conductor plate carries the speed sensors and the shift and pressure solenoids; when one fails the car falls into second-gear limp mode and codes such as P0715 or P0748-P0753 are typical, with nothing wrong in the packs. Leaking input-shaft sealing can also starve the converter circuit and cause lockup shudder. Check the level hot, read codes, then drop the pan and look for friction material. Our ML 722.6 shift problems guide and the pressure control solenoid symptoms guide cover the electrical side, so you only replace frictions when they are actually the problem.
This module is listed for the 1998 722.6 and is the 1998-up large-ID K2, thick-K3 design. Because 1998-2000 transmissions can carry either the earlier standard K3 or the thicker one, measure one of your original K3 frictions against this set before assembly. For an earlier unit with standard K3 plates, use the 1996-2000 module; for 2001-up units with the small-ID K2, use the 2001 module. Send us your year and VIN, or a photo of the K2 and K3 plates, and we will help confirm. All 722.6 parts are on the 722.6 / 722.9 parts page.
| Fits | 722.6 1998 |
| Part type | Clutch Module |
| Condition | New |
| Brand | OEM |
| Reference | R78119B |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Measure one of the original K3 frictions with a micrometer and compare it to the plates in this set. Measure across the lining on both sides, not at the teeth. If in doubt, send us a photo and your VIN.
Not without correcting the clearance, and the stack may still be off. Use the module that matches your drum so the pack clearance can be set with the normal selective snap rings.
It covers the friction plates only. A proper rebuild also needs piston seals, sealing rings, gaskets and a filter, and the steels if they are heat damaged.
P0715 is an input speed sensor code, and on the 722.6 that sensor lives on the conductor plate. Clutches may be fine. Diagnose the electrical fault first.
Sprinter vans used the 722.6 as well, but van units can differ. Check the K2 inside diameter and K3 thickness or send the year and VIN before ordering.
