A thump in the rear. Hilfe!! - PeachParts Mercedes-Benz Forum

PanzerSD · #1 01-19-2007, 10:25 PM

I've had this nasty thump on the right hand side of the rear suspension. I looked it over really well, nothing is cracket or otherwise worn out. I know the shocks are suspect, but I've never heard a bad shock make this noise.
Is there any chance that the upper shock mount rubbers could be sacked out?

The only way I can describe the noise is as though I had an empty wooden box in the trunk and it was bouncing around. Now, I DO have a wooden box in the trunk, but I removed it and the noise remains. Tied down or otherwise removed everything in my car that could make a noise and it's still there.
Also, it's a "vertical" type of noise. I swerved the car hard in a parking lot and the noise wasn't there, but when I drove in a straight line over a nice speed bump ( at any speed mind you) at about 30Kmh it's a distinct banging sound from the right rear corner. sounds like the axle is bouncing. but the snubber and the droop catch are not worn shiny as with regular top/bottoming out.

sublettm · #2 01-19-2007, 10:30 PM

I'm not that familiar with the 80SD, but do they have axle boots like the 123's? If so, are they torn? If so, you might in fact have a bad axle. The noise you describe sounds like the same noise I have encountered in two of my cars when I had axles go bad.

JimmyL · #3 01-19-2007, 10:43 PM

Quote:

Originally Posted by Got_The_Benz

but the snubber and the droop catch are not worn shiny as with regular top/bottoming out.

Snubber and droop catch???????

captainmonk · #4 01-20-2007, 01:40 AM

English in the tundra is different

Sounds like rear axle most likely culprit having just replaced 4 of them on Dad's and my car

t walgamuth · #5 01-20-2007, 08:11 AM

the shock could be just loose. i had this and it went undetected even as the alignment shop put all new bushings on the rrear of my blue 240. grrrrrrrr!

it was a not horrible rattling sound. not unlike a loose exhaust system.

tom w

PanzerSD · #6 01-20-2007, 05:43 PM

Quote:

Originally Posted by JimmyL

Snubber and droop catch???????

Oh c'mon! you've never hears of a snubber or droop catch??

When the car is lifted and the suspension left to hang, that's called droop, the droop catch is the metal tang that Mercedes welds to the lower rear control arm to stop the shock from having to take the full force of the spring pushing down on the control arm (or swing arm)

The Snubber is the rubber bumper that prevents the sduspension from traveling too far upward..

PanzerSD · #7 01-20-2007, 05:45 PM

Quote:

Originally Posted by sublettm

I'm not that familiar with the 80SD, but do they have axle boots like the 123's? If so, are they torn? If so, you might in fact have a bad axle. The noise you describe sounds like the same noise I have encountered in two of my cars when I had axles go bad.

yeah, I have boots on my axles, and they are I guess in fair shape slightly cracked but not torn or leaking.

a revelation...the inner differential seal is leaking a bit, on the side with the noise, could a bad axle moving around enough to cause a noise damage the seal and cause it to leak?

JimmyL · #8 01-20-2007, 05:51 PM

Quote:

Originally Posted by Got_The_Benz

Oh c'mon! you've never hears of a snubber or droop catch??

Those were my guesses, but I sure didn't know for sure...... I guess I've had a sheltered life......

I thought droop catch might be granny's lap......