W140 Rear Susp thump

[petel]

97 S500 coupe with 152k. Thump from left rear when going over potholes manholes etc. Dealer Diag was air cells. 2 new air reservoirs and 500 bucks later still have thump. Are oem shocks long in the tooth at that mileage? Also, I had similar issuse with an XJS and it was bad bush on top of front strut. Not familar with W140 so do not know if same problem is possible cause.

[SteveUrban]

A mechanic friend of mine told me that if the rear shocks squeak, you have to replace them. That could be part of your problem. Also, did you go back to the dealer and tell that they did not fix the problem?

Steve

[Kebowers]

The rear shock has twolinked pistons inside it, and if they seperate (fail) ,this will casue a very noticeable THUMP and jolt over every bump when the pistons knock together again. Solution is to replace the offending unit. (Check used parts suppliers first--they are $$$. ) The shocks do not wear out--just change the suspension oil every couple of years.

[daddiojiggy]

i have the same thump and although i have a sedan i think we share the same problem.i KNOW what my problem is and it is indeed the rubber bushing inside the shock end.however the REAL problem is replacing the bushing while keeping the shock(mine is okay).i haven't found any body/way to do this but i can't think it's impossible.i also haven't spent alot of time with the car lately.i think what happens is the bushing becomes dried out and induces the noise.you say you had it on your jag, how did you resolve that problem?

[plink49]

You did indeed correct the original problem by replacing the accumulators (air-cells you called them) but the damage had already been done and you need to replace the upper bushings on the struts. They are inexpensive ($35?) plus labor.

[daddiojiggy]

are you guessing the price of bushing replacements or have you had it done?if so how did they do it?tia!

[plink49]

I'm estimating but not guessing. Yes, I did have it done this past February. A local indy did the work and after consulting the incoice, the bushings were $42 each and labor was $59 each. From what I understand, once the accumulators and upper bushings have been replaced they should be good for another 100-150k miles.

[daddiojiggy]

i would think getting that kind of extended mileage is not too much of a stretch.from what i've pieced together about these shocks, they're very strong and reliable as long as you say the accumulators are replaced(and i would think, replaced at the right time).a couple of hundred bucks might seem like alot to some - until they realize how much the shocks for the are!
now,i'll have to find a shop that can do this repair!thanks!