W210 squirrely rear suspension.

[coneybiller]

Well I've just had all of the rear multi link arms replaced. It now creaks and feels very crashy and unstable when going over bumps. I've also noticed that the NSR is slightly lower than the OSR. The shocks seem to be returning with 2/3 bounces and the springs aren't broken.

I actually nearly lost it in a 50mph contraflow section of the M4 yesterday. After crossing the central reservation area following the lane, I went over a grate and the back end went all squirrely and a lot of correction had to take place to keep it in a straight line! Unnerving is an understatement! It seems to do this also when going over a pothole at slower speeds.

Had the car up on a ramp since the arms were replaced, but cannot see anything obvious! All bolts are tight and all seems present and correct!

I'm wondering if the person who carried out the replacement, actually tightened the arm bolts without a load on the hub (IE suspension compressed) so to pre-load the bushes? Could this be a possible cause?
Do you think I should try and back off the nut and bolts and place a jack under the hub to simulate suspension load, then re-tighten the nuts/bolts?

Cheers

Ben

 

[GordonTarling]

I think you need to get the rear subframe mounts thoroughly checked - very common problem on the W210.

 

[Charles Morgan]

As above, Sub-frame mounts and sub-frame bushes- they do an immense amount of work and unless you look carefully it's very difficult to see any issue.

 

[coneybiller]

Hmm, OK. Sounds very plausible. I know the rear sub-frame bushes are worn, but I was told not to worry too much. Now I'm presuming that the rear arms are a lot stiffer and now transferring weight from the once squishy arm bushes, to the rear sub-frame mounts. It would explain the sideways movement I get when going over potholes.
Great, Que another £350+

 

[coneybiller]

Well, I found yesterday that after driving all the way to Reading via the M4, I had a very bad vibration from the rear, enough to vibrate the rear view mirror! When i pulled off the slip road at reading, the car was bumping up and down, so I assumed that I had a flat tyre. Nursed it 2 miles to work and found the NSR tyre had completely worn. It had worn through both layers of steel wire and the canvas was bulging out of the middle. I was absolutely shocked to say the least and am very thankful I didnt get pulled over or even worse, crashed!!!
The other tyre was completely bald but no wires showing. So today I've had both rear tyres fitted and found that both rear wheels were toeing in very heavily. Needless to say, I've had the alignment done as well and now its back to being silky smooth!

Whats even more gutting, is that I've only had those tyres since the 14th of April!! Silly boy. I shan't be forgetting the tracking in a hurry again!!!