Control Arm Bushings - PeachParts Mercedes-Benz Forum

krodkey · #1 07-18-2007, 09:47 AM

I have a 91 190e. It has developed a vibration from approx 40-70mph. The vibration gets much worse while light to moderate braking. During heavy braking the vibration will stop(most of the time). I have rotated and changed the tires without much luck. Most suspension components have been checked replaced. The vehicle has been aligned, but the vibration is still there and the inside of the front left tire wears dramatically faster than the any of the other 3. The only thing I can think of that has not been replaced are the front control arm bushings. Could these cause this type of vibration and wear?

david s poole · #2 07-18-2007, 09:51 AM

yes,if you will jack up front of car and use a big screwdriver in beside the rear one of the two lower control arm bushings you will see a lot of movement.this actually allows the wheel to move back in the wheel well with a loss of alignment.

krodkey · #3 07-18-2007, 09:55 AM

I tried to pry them around a little, but maybe I was too gentle. The bushings do appear to be dried out, which is why I am suspecting them as the culprit. Any suggestions on the type to use: urethane vs. oem replacement.

G-Benz · #4 07-18-2007, 10:11 AM

I suffered though the vibration for years and did the usual, alignment, tire rotation, balancing, etc. Even went as far as faulting the wheels and replacing the set!

My indie didn't find any free play in my front suspension, but discovered that the idler arm was bad. That was a $50 part, and the vibration vanished completely!

Not to discourage you from replacing the control arm bushings, as they are probably overdue for replacement.

krodkey · #5 07-18-2007, 11:50 AM

Can the Idler arm bushings cause tire wear on the driver's side as well as the vibration?

david s poole · #6 07-18-2007, 12:02 PM

bad idler arm bushings will cause free play in the steering and if you lay under car while someone moves the steering wheel around centre you will be able to see the idler arm move up and down.

krodkey · #7 07-18-2007, 12:10 PM

I have not paid that close of attention to the setup of the steering components under the car. Will idler arm play allow for the tires to move independently of each other? The reason I ask is that after alignment I still have tire wear on the inside of the drivers side front tire.

sbourg · #8 07-18-2007, 12:25 PM

Due to road camber, the toe-out condition resulting from a worn idler would tend to cause a drift to the right (in the USA, anyway, no pun intended). This would require a compensating steer to the left, scrubbing the inside of the driver's side tire. Worn idler bushings could also cause vibration, and most noticeably - road wander and imprecise steering.

Steve

krodkey · #9 07-18-2007, 12:30 PM

The car was pulling to the left before the alignment. Now there is no noticeable pull but all other symptoms remain.

sbourg · #10 07-18-2007, 12:58 PM

You don't give a time frame on the alignment. If it was recent, then you may no longer have the tire wear issue. A PROPER alignment specifies applying a calibrating force pushing apart the front of the front tires. This simulates road friction's affect on toe angle at some arbitrary road speed. If this was not done, a worn idler will still cause tire wear - any pull and compensation may not be noticeable at the steering wheel, but it will at the left front tire.

If the idler bushings have never been replaced, they are worn out in that model. It was not a difficult job to do in ours, and the parts are cheap. You will at least need toe adjusted after.

Steve

krodkey · #11 07-18-2007, 01:06 PM

Thanks, idler bushings are on the way. I am also going to investigate the control arm bushings tonight. I will post results this weekend after I complete the work.

Thanks again!!

krodkey · #12 07-20-2007, 03:05 PM

Idler arm bushings are in (didn't expect to have to take off my exhaust manifold to get the mounting bolt out). The vibration seems to have been dampened a little but is still there. That tells me there were two sources for the issue. Control arm bushings will be here tomorrow. I will post back with the results.

sbourg · #13 07-20-2007, 03:55 PM

With careful bolt and bushing maneuvering, I didn't have to remove the exhaust manifold on our 2.3. If yours is the 2.6, that may not be the case. However, it's also possible your motor mounts are worn out, reducing clearance. That caused motor vibration and noise for us, but not shimmy. Still, a loose drivetrain might have unexpected consequences... Just a thought, if the control arm bushings don't solve the problem.

Steve