What are these and how can I change them? - PeachParts Mercedes-Benz Forum

Cal Learner · #1 09-04-2010, 08:03 AM

Boys, take your playground spat outside. The OP just asked for a little help identifying these parts. Typically called differential bushings, but EPC refers to them as rubber mounts for the axle housing to rear subframe. The photos tell me yours are overdue for replacement. P/N 124-352-77-65

punkinfair · #2 09-04-2010, 09:19 AM

the mounts/bushings in your photos actually look pretty good. the left one is a bit off-center but for instance the ones in my car are much worse. and when they're bad they don't normally make a squeaking noise, more of a clunk. i think the squeak is coming from somewhere else.

Gilly · #3 09-04-2010, 09:50 AM

I'd say if he can duplicate the noise by pressing up on the final drive, he's found his problem.

On the "semantics" episode, I was siding with ChasH until the statement, well here, I'll quote it:

Quote:

Fact is the final drive might not contain a differential.

Ummm, can you give an example of that, I'm confused and will readily admit it. I might be missing something, something that will give me an "Oh, YEAH!" moment. I love those.

And as far as the battle itself, if this would help get peace talks to ensue, in a Mercedes shop, if someone has worked on Mercedes for awhile, with prior mechanical experience, eventually you see the term "final drive" used enough that you start using that instead of the more generic term "differential". Before i was exposed to Mercedes, I know this is the term that was used, either that or just "rear axle". Of course I'm a little older and these terms were used regarding rear wheel drive American cars, before Chevy shocked the world with the Citation!

Anyways, when you start to work on Mercedes, the "final drive" name is used a lot, especially in the maintenance sheets, ie "check final drive oil".

In the REPAIR info, such as the microfiche sheets, it is usually referred to as the "Center Section".

I will also use the term "Punkin' " (pumpkin), ie "don't drop that punkin' on your head!"

Some of these terms might be used more or less frequently due to location, maybe? I don't see the big fuss in correcting each other, there are lots of terms like this, differntial, rear axle, final drive, hey you know what is being talked about, big deal. For some reason, I would be more apt to use the term "final drive" when talking about the fluid change, but if I had to REMOVE it, I would say something like "ah crap, the center section has to come out!" It's always strange for a guy who is used to solid rear drive axles to start working on IRS, to me that was always high tech Jag or Corvette stuff, it was a real leap to go into IRS.

If someone would ask about the differential though, I knew what was being talked about, no need to do a correction, sort of like if someone offers me a soda, and where I live they always call it "pop" instead, no reason to say "huh?", I know what it is! (and usually I want to say "only if you're out of BEER!").

Gilly

david s poole · #4 09-05-2010, 08:54 PM

well put gilly,you silver tongued devil you.-------the other parts of that rear suspension that squeek are the outermost bushings that support the rear wheel assembly.that doesn't preclude the replacement of the rear diff support bushings if they are needed and most are.

Gilly · #5 09-05-2010, 10:16 PM

TY Mr Poole........

big dog 2 · #6 09-06-2010, 12:14 AM

David!

My 1989 300E has a light clunking sound from the rear. My two bushings discussed in this thread are also shot. The other link bushings are old rubber but visually appear to be OK. Could these bushings be the culprit or maybe the subrame mounts?

david s poole · #7 09-06-2010, 09:41 AM

the bushing on the left side will be the worst and it can cause a loud clunk with foot on brake as you shift into gear.

Chas H · #8 09-05-2010, 12:53 AM

Quote:

Originally Posted by Cal Learner

Boys, take your playground spat outside. The OP just asked for a little help identifying these parts. Typically called differential bushings, but EPC refers to them as rubber mounts for the axle housing to rear subframe. The photos tell me yours are overdue for replacement. P/N 124-352-77-65

I answered the OP in the first reply to his questions.
As you have found, Benz does not refer to the item in question as a differential mount, as suggested by others.