Suspension Noise Question - PeachParts Mercedes-Benz Forum

Tump · #1 03-22-2004, 03:22 PM

Hi --

Last weekend I changed my stock shocks to Bilstein Sports with poly urethane shock bushings to match my H&R Sport 1.5 inch spring drop. Since that time I hear a clunk or thump comming from the driver's side rear wheel when driving over very bumpy pavement at low speeds (20 to 30 mph). At high speeds (anything over 60) there is no noise regardless of the size of the bump.

It sounded like something loose in the trunk bouncing over bumps so I removed everything in the trunk including the jack and there was no change in the noise.

What could this noise be caused by? I read or heard that perhaps this could be caused by the bolts holding the top of the shock to the trunk loosening up a bit. However, I don't think this is the case since the bolts were just installed and tightened.

The ride is firm and tight as per the AMG design. The only difference from stock is the ride height and the noise.

Any ideas?

Thanks,

manny · #2 03-22-2004, 04:51 PM

I assume that all the components were tightened with the wheels on the ground ?

Tump · #3 03-22-2004, 06:14 PM

No, the components were not tightened with the wheels on the ground. But we did place a hydraulic jack under the each control arm and jacked it up before tightening. Is this the problem -- please explain the theory of having the wheels on the ground. Perhaps we didn't jack the control arm up enough.

Thanks

manny · #4 03-22-2004, 06:45 PM

According to " The Book ", whenever you disconnect suspension components ( shockmounts upper & lower, swaybars, etc. ), you should do all your final tightening with the weight of the vehicle resting on the wheels.
Things like lower shockmounts are especially important.
It also does'nt hurt to bounce the car a few times, before tightening upper/lower shockmounts, just to be sure everything is seated correctly.
Aside from that, I hope the poly bushings don't contribute to the noise you're experiencing.

Tump · #5 03-23-2004, 06:21 PM

Thanks for the help Manny. We tightened up all the bolts on the top of the shocks with the tires on the ground and bounced it a few times. I then drove it around. The noise was the same.

We put the car on a lift, removed the rear driver's side wheel where the noise was comining from and removed the plastic cover over the lower control arm. Lo and Behold the nut conecting the lower end of my MRP aluminum end link fell out. We put it back on with a lock washer and put a lock washer on the other trick end link and the noise disapeared.

The rear shocks did need to be tightened up though, the upper bolts were not on tight enough.

Thanks again for the help.

manny · #6 03-23-2004, 11:25 PM

Tump

Well, that makes it about 6 or 7 people around here, that owe me a beer.

My diagnosis may not have been correct but, at least I held your hand.

Tump · #7 03-24-2004, 09:25 AM

Manny --

I used to live in Montreal and still have family there. If I'm in Ontario I'll look you up and buy you a beer. Similarly, if you happen to be in the New York City area, drop me a line I'd be happy to take you out for a drink.

Thanks