Trampas Stern

I have just replaced every rubber part in my suspension, brand new tires and alignment. I also replaced rear subframe bushings. Now at high speeds, above 70mph, the car wants to wonder like you have strong crosswinds.

I figured I did something wrong in suspension and took to a suspension shop, $600 later they could not find a problem. I was wondering if anyone else had seen this before?

Thanks

bbirdwell

The first thing that comes to mind is toe-in of the tires and front inner and outer tie-rod ends. FWIW, when my W210 had zero to slightly positive toe, it would wander all over the highway and felt very unstable; required constant steering input corrections from me. Corrected the toe from positive to negative, and it now tracks straight and true.

Look up "toe plates alignment" for ideas. Also, look to Youtube on how you can verify the toe on the front and rear wheels yourself using strings and ruler or metal plates and ruler. Remember to verify and, if necessary, correct the rear wheels first to prevent "crabbing".

Trampas Stern

I have had it aligned at two different shops, as such I doubt it is a toe in issue. Also the problem only occurs at speeds about 70MPH. Also tried two different set of tires.

Thanks

MattCordell

Your rims are they bent or cracked?
A damaged wheel can cause you strange behavior on the road

Trampas Stern

I do not think I have a rim issue, I am sure tire store would have noted during balancing on new tires. Also this problem is not always consistent. That is when you get above 70MPH is appears to be dependent on the road. You will be going along straight and then with no movement in steering wheel car will jump to one side. Then a second later it jumps back, like it got stuck in a rut on the road briefly. You never feel anything in steering wheel. You let go of the steering wheel and the car will track straight, but just jumps around...

The rack is less than year old, all the tie rod ends, ball joints, shocks, control arms, and rear sub frame bushings are new. As such the only thing I can figure out is that two different shops did alignment wrong or one of the new suspension parts are bad. Again I did take to suspension shop and had them check everything, they reset the prebias on the suspension parts but found no problems other that tire store had installed SUV tires. Putting touring tires on did help, but did not solve all the problem. I do find lowering tire pressure to recommended pressure on fuel door helps, but does not solve all the issues.

I replaced suspension parts as the thrush bushing and such were all worn after 22 years, and one of the front lower control arms was rusted where they break, so rather than piece mill the replacements I just replaced everything in suspension to be done with it.

I am debating on putting a gopro camera under car looking at suspension to see if I can find something moving. Of course I have tested everything with pry bars (suspension shop did as well) and no problems were found.

I wanted to get alignment at Mercedes but local Mercedes dealer told me they will not work on Mercedes older than 2000. I assume the quality of Mercedes dropped where they have too many cars in the service department... From my W126 years I know that only Mercedes could align the W126 correctly, no one else knew about putting pin in the steering box, so I always got alignments at Mercedes.

I will take back to suspension shop with new tires and get the alignment check again, just to be sure.

nelbur

My '97 rear end would jump to the side when ever I hit a bump. I had it in the shop to try to figure it out and they found nothing wrong. The tech said that this rear suspension is sensitive to worn shocks. I replaced the shocks and the problem was gone.

raymond g-

Has the car ever been in an accident? (frame work out of spec?)

I wonder if you can clamp a gopro camera just under the door and drive to see if any visible oscillation can be seen. Or, if you have a kid brother who will do anything you ask...

Not related to your situation but once I had a high speed vibration/wander anomaly and after months, figured out that it was a weakness in the sidewall of ONE tire. As it warmed up, the sidewall hemorrhoid grew and unbalanced the tire. By the time I got off the freeway and pulled over, the blister shrunk and receded back into the sidewall and remained invisible for months. Damn-dist thing

I hate to see you chasing symptoms on a guess and dropping money down a hole....e.g. not knowing which end is causing it. Maybe try to isolate it to a corner if you can ?

Wonder if you can strap it to a dyno and see if the rear does anything unusual at high rotation?

Trampas Stern

The car has 423k miles on it (OM606) and I paid $2700 + $1200 (used transmission) 13 years ago. Since then it has been minor maintenance issues, glow plugs, fluid changes, radiator leaks, brakes, etc. So the car does not owe me anything and runs great as such I was willing to dump money into fixing.... I was looking at replacing it with a newer GL series diesel but it looks the OM642 are not very reliable (relative to OM606), especially the bluetec ones... As such I figured just fix everything on the W210 and drive for a few more years until I figure out what car I want next.

Thanks

bbirdwell

Did you also replace the rear multi-link suspension components?

Trampas Stern

Yes I replaced, all the multi-link parts, as well as rear swing arm bushing, shocks, sway bar links, and sway bar bushings. Idea was if rubber or could likely go bad in the next 100k miles it got replaced. I even replaced rear springs last year as the rear end was sagging...

MattCordell

Did you replace rubber-metal bushing on each rear hubs?
I think they were filled with a fluid or something, can't remember exactly?
This bushing collapses and car will perform bad

Trampas Stern

I think you mean the subframe bushings? If so then yes..
If you mean the lower bushing on the read hub which is a swivel bushing, then yes.

I replaced everything having to do with suspension movement.

Thanks