W124 differential mount R&R -- DIY? - PeachParts Mercedes-Benz Forum

Jeremy5848 · #1 06-12-2011, 06:41 PM

Most W124s including my '87 300D Turbo hold the differential to the rear subframe with three bolts (the 400E and 500E are slightly different). The two bolts at the rear are cushioned in healthy rubber grommets. These, like anything else made of rubber and going on 25 years old, wear out. I'm trying to decide whether I can replace mine myself.

Of the two grommets in my car, the left one is the worst. With the car up on jack stands (rear wheels barely touching the ground), the weight of the differential hangs from the subframe and a gap shows where the left-hand rubber grommet is starting to fail. (BTW, the bottom of the grommet is supposed to be missing a section of rubber; the new ones do too.)

If a jack is placed under the differential to take the weight off of the subframe, the gap in the grommet goes away. Clearly, the differential can move up and down this much during driving. The grommets should be replaced.

The forum has a few threads on this subject, with varying opinions of its DIY-ability. None have much in the way of pictures or detailed instructions. The major problem is that the grommets must come out and go in from the front, not the rear. The differential must be lowered at least 5-6 inches to gain access. FSM suggests completely removing the differential, which requires much of the exhaust system and the rear half of the driveshaft to come off first. A special puller ($150) is required for grommet R&R although I should be able to do without it.

As a DIY project, this does not look like a lot of fun. As a shop or dealer project, it looks costly. The grommets are not expensive (~$25/pair); it's all a matter of labor hours. Given that the grommets are not yet completely disintegrated (no clanking noises or stability problems), I'm tempted to let it go for the time being. Your comments are invited.

Jeremy