jpw_amg55

Hi All -

Have started hearing a clunk from the front of the car when going over bumps in my 2004 Sl 55 (really noticeable when over a speed bump at low speed).

Ball joints? I hear the lower ball joints are part of the suspension strut and can not be replaced - is this true?

Any good aftermarket items to research?

thanks!

Blackbird76

Be surprised if the ball joints cannot be replaced...

I know lower control arms are a common problem with these cars and almost always have to be replaced within the first 10 years, but, that's more of a knocking sound when you turn the steering wheel. Easy to distinguish.

Sounds like it could be the shocks, have those been checked out?

kbob999

Could be a ball joint, but I'll bet 10:1 it is the inner bushing on the lower control arm. These typically last 50-75K miles, and can be pressed in. You can buy a tool to DIY for about $160. Ball joints need to be removed at the outer end of the arm to pull the arm.
The arms are more expensive, but can also be swapped. I've done the bushings on both of my AMG's.
Pull the lower panel and inspect right under the engine. If cracked, they need to be replaced ASAP as the wear can reach the subframe and cause major ($$$) damage.

Nor Cal SL55

+1 on the bushings. They will make a clunking noise when applying the brakes at low speed, forward and backwards.

jpw_amg55

I'll check that as a possibility. thanks to all for their input!

latemodel21

Early R230s (my 2003 SL55 for example) had non-replaceable UPPER ball joints (entire upper arm gets replaced) whereas later models have a bolt-in (replaceable) upper ball joint (you CAN put a newer arm on an older car). Lower ball joints have always been replaceable (at least as early as my early 2003).

As mentioned, lower arm inner bushing are a common fail item (and not particularly hard to replace if you have a shop press). However, if memory serves, mine made more of scrape/whine than a clunk when they let go.
A decent alignment shop would likely be able to shed some light on this shortly after getting it up on a lift.


You may also want to check all the chassis stiffening straps for tight hardware.


hope that helps,
Chris