Upper Control Arm Ball Joint, is it bad? - PeachParts Mercedes-Benz Forum

derburger · #1 02-09-2008, 06:22 PM

I've recently had major suspension work done, basically the lower suspension and all the rubber replaced. I heard clunks from both the driver's and passenger's sides, and both upper control arms were replaced, the clunks went away. After a dealer alignment, the car handles and rides great and the alignment stays in specs. However, I have a clunk that is similar or identical to the clunks I heard before now happens when going over bumps and divots in the road, I hear it from the passenger side. My guess is the ball joint in the new upper control arm is defective, it does not look right or like the other upper control arm. The one on the left is Genuine MB (my mechanic had a working spare), the one on the right I assume is aftermarket and that's where the clunks come from. I have attached of the right side upper control arm for your viewing.

Also, the clunks could be related to the botched alignment the MB dealer gave me. My suspension was new and tight, but my mechanic took it to Midas for an alignment(big mistake) and it was bad and cupped my tires on the outside edges. I took it to the MB dealer for re-alignment, and drove the car home with horrible clunking from the suspension. The clunking was completely obvious and I noticed it the second I left the lot. I brought the car back and they re-tightened the suspension and the clunks went away. I took the car back because of more clunks I heard and more tire wear, the driveshaft was loose at the pinion bearing(?) and the wheel balancing from (Sears) was faulty and they rebalanced the wheels. The alignment was within specs so that wasn't what was wrong. But I still hear a clunk from the passenger's side!

The balljoint in the upper control arm looks weird to me, perhaps that is the cause of the clunk, but I still have no idea what MB did during that alignment that caused by suspension to clunk. Any ideas? The entire suspension is new and so are the front shocks.

derburger · #2 02-09-2008, 08:51 PM

Disregard the too long, didn't read story about my suspension, do you think that boot looks bad?

toomany MBZ · #3 02-10-2008, 05:07 AM

Yes, any time a boot is torn, that's cause for worry. Spray grease in there till you can replace.

vstech · #4 02-10-2008, 07:22 AM

Quote:

Originally Posted by derburger

I've recently had major suspension work done, basically the lower suspension and all the rubber replaced. I heard clunks from both the driver's and passenger's sides, and both upper control arms were replaced, the clunks went away.the one on the right I assume is aftermarket and that's where the clunks come from. I have attached of the right side upper control arm for your viewing.
I brought the car back and they re-tightened the suspension and the clunks went away. I took the car back because of more clunks I heard and more tire wear, the driveshaft was loose at the pinion bearing(?) and the wheel balancing from (Sears) was faulty and they rebalanced the wheels. The alignment was within specs so that wasn't what was wrong. But I still hear a clunk from the passenger's side!

The balljoint in the upper control arm looks weird to me, perhaps that is the cause of the clunk, but I still have no idea what MB did during that alignment that caused by suspension to clunk. Any ideas? The entire suspension is new and so are the front shocks.

Um, what?
that is in no way a new upper control arm... My Guess (assuming is a bad idea) is both arms are used... and the passanger's is bad. sorry.

derburger · #5 02-10-2008, 12:53 PM

I'm pretty sure that passenger side was the used one now, I remember my mechanic had to take off the air filter housing to do that one. I came back later and the other one was taken out of the plastic in front of me and put in.

Crap, they are supposed to look like this.

I guess I didn't luck out when my mechanic said he had a working used spare. I think I'll try to Diy it, except my last diy took me 8 hours... just to replace the front shocks. I kept forgetting "rightey tightey, leftly loosey" and I was using a tiny 10mm wrench. Perhaps I inhaled too much PB blaster. Holding up the control arm with my floor jack is scary. The job took my mechanic 1 hour exactly to do so it should take me 8.

To provide more support as to the ball joint being bad, the car is odd on the highway and there is about and inch more play in the steering than normal.

Any advice for doing this job? Diesel Giant's guide looks good and I do have all of the tools necessary this time. http://www.dieselgiant.com/mercedes_upper_control_arm_repla.htm

toomany MBZ · #6 02-10-2008, 05:40 PM

dieselgiant has much info. When tightening the nylock nut, were the ball joint to spin before you reached the proper torque, back it out far enough to fit a 6mm thick spacer, I used an open end wrench, then tighten down to "seat" the ball joint, loosen as bit to remove the spacer, proceed.
Also I could not get the torsion bar to line up, so I got a long bolt of the proper size, pitch etc. with the duo cone bushings in place, it held for me to back out, and install the old bolt with washers.
Next time on the front shocks, use a thin walled 12 point 10mm socket for the lower bolts. It came with the shocks I ordered.
Here's a pic of the one I took out... what inner bushing!?
Good luck.

TheDon · #7 02-10-2008, 06:12 PM

it should take no more than 45 minutes to swap out the upper control arm

NC Benz · #8 02-10-2008, 09:01 PM

Quote:

Originally Posted by TheDon

it should take no more than 45 minutes to swap out the upper control arm

Agreed! Did one on my 83 this weekend and I have never done front end work before. Stupid easy!

Now I drive straight and hopefully wont go through tires as fast.