MBS430

hi MB enthusiast friends,

I have 2008 S550 RWD.
I experience grunting & clunking when driving speed bump and just replaced the sway bar, both end links and sway bar bracket. It resolved the major creaking sounds but apparently there is another grunting sound, potentially masked by the sound from the way bar at the initial diagnose.
The current suspect the RIGHT control arm.
Questions:
1. from what I searched, I found most of the issue is RIGHT control arm. anybody has idea why mostly right? maybe more weight on the front right?
2. should I might as well replace both RIGHT and LEFT?
3. is the ball joint replaceable or do I need to replace the whole control arm?

Thank you much in advance for your help

Drives550

Doesn't exactly answer your question, but after going round-and-round with my dealer on "creaking noises" and what felt to me like hitting bump-stops on lateral movements, both problems were finally solved thus:

1. Thrust Arms (what the dealer called them on the invoice), a.k.a lateral arms (what mbwholesalepartsonline calls them) a.k.a. control arms (what pelican parts calls them) (part no. for the right 221-330-66-11) got rid of the bump-stop feeling on lateral movements (make's sense to me, therefore, to call them lateral arms). This was the one the dealer had the most difficulty identifying as the culprit. They kept telling me nothing was wrong, but I could feel it and finally took them on a ride. Dealer was only going to replace the one I complained of (left side) but I had them do both.
2. Lower Control Arm a.k.a spring control arm (what mbpartsonline calls them and my dealership)(part no 221-330-77-07 for the right) got rid of the creaks/groans. The bad one here was on the right, but both got replaced at the same time.

So, sometimes my dealer did both, sometimes not. I could be wrong but pretty sure you can't buy just the ball joints. All my stuff was under warranty, so I never cared about cost (I've traded the car now that the warranty is up).

YCHU

Speaking of the Right side, isn't it also the right side airmatic strut that goes out first?

lionsfan54

Which way does the engine torque? Perhaps that's putting more stress on that one side?

JDowney

Hi

Had similar issues on my S350, and was told that is is normal wear and tear. Ended up replacing both lower control arms, and did a front and back brake job. The car is now running a smooth as it ever did when it was new...

Jeff

lionsfan54

At least on the V-12 cars all those front end parts are considered consumables. They carry a tremendous amount of weight and are subject to some serious twist! The good news is that the parts are pretty cheap and any shop can install them. And, once replaced, you're back to a magic ride

tx170754

lionsfan54

That's crazy. Do you drive hard? My Kumhos have about 10k on them and appear in good shape still.

tx170754

I'm not driving hard at all, not so sure why they're so bad but in the end I guess I have to live with it and eventually order two new tires next year since both the SL and CL will be in my garage for the winter.