rear differential mounts
 

how often do these go bad? I can see 2 of them under my w124, and the left one shows a bit of deterioration. I have a noise in the rear end, going over speed-bumps, may be worn shocks, i did an under car inspection and noticed the diff. mounts. I suspect they would only make noise under torque situations, if any noise.

what do you all think/know? Hard diy job to do diff. mounts, and i should do both i take it, if am in there.

FQ

If they are loose it usually shows up as a very distinct clunk under initial acceleration or deceleration. Mine were very annoying because my 300E is a manual transmission car, but I expect it would be noticable with an automatic.

To change them you absolutely must have a puller. You can't drive them out with a hammer because you will destroy the sheet metal carrier. My brother in law is my tech at the dealer and loaned me a puller that he made. It worked great.

You can buy a good puller from this site or for a little over $100 at performance products. If you check with the parts shop here, I expect that they can sell you the same one for the same money.

Don't dare replace one without also replacing the other. Also there are two donuts on the passenger side pinion housing. You should probably replace them or at least check them while you're there. They are not so difficult and require no special tools so you can do them any time.

Good luck,

thanks Larry.

The noise i am hearing is something else. I put the car on a lift and checked with a tech, and the diff mounts seem fine. My noise is strictly going over a rough bump, such as a speed bump, and i only hear it during slower speeds from the left rear of the car. We checked shocks, springs, all mounts, and bushings, even anything loose in the trunk, such as spare, and cant isolate it. It is a hollow sounding clunk. I still think it will go away once i replace all struts and shocks, and all necessary hardware associated with them next week.

fq

About your noise!!!
 

Reading your post and trying to Imagine you noises..MB has a Plastic connecting rod that mounts on each side .. It connects to the sway bar on one end and to your rear break plate.. look under your car there is one on each side..they are fairly easy to change and not very expensive either...... when new they will be a off white color or grey. Most of the time it will be that knocking ..hollow sound you are hearing....... Let us know what you find.............Pete GABBYS MB REPAIR

A loose or hard and shrunken sway bar mount will thump on the floor pan, too. Always at low speed when one wheel is deflected and not the other.

Take at look at those while you are under there. If they are bad, expect to replace the sway bar mounts up front, too.

Peter