W124 intermittent front end vibration
 

On occasion (at speeds of 40mph and up) the front end of my 1987 300D will vibrate. I can feel the vibration in the steering wheel. Sometimes if I brake or change lines, the vibration goes away. Other times it goes away by itself. It's only for 10-15 seconds at a time, but is getting quite annoying. A couple weeks ago there was NONE of this, last week it was rare, and now I'm getting it almost every time I drive the car.

The steering damper is new, the ball joints and tie rods look good, (no rubber is torn). :confused:

Check tire condition, looking especially for cupping (bad shock). Jack the front wheels up and check for loose ball joints, tie rod ends, etc. Just a visual check of the boots won't necessarily tell you if they are loose.

Control arm bushings can be bad too, but the usualy cause of such vibration is either a bad tire or a bad shock -- bent rim will also cause vibration, but it won't be intermittant...

Warped rotor and/or sticking caliper will do this too.

Peter

Thanks Peter. The rotors look fine, no abnormal wear and no grooving. The ball joints and tie rod ends didn't seem loose, but a sticking caliper is a possibility. Are there other symptoms of a sticking caliper?

Lousy gas milage and a hot rotor.

Peter

Did you check the idler arm bushings?

Play in the bearings?

Are those balljoints original? Look again with the weight of the car resting on the control arms, which unloads the balljoints.

OK. I replaced the idler arm and the car still vibrates rather violently at 40mph and up. :mad: When I turn the steering wheel, the vibration stops. This is what the old idler arm looks like, versus the new. I don't think it was the problem. The steering damper is relatively new. Ball joints seem good. Could it be the drag link? It DOES have some up and down play, but I'm not sure if it's supposed to be that way.

http://members.cox.net/w124/idlerarms.jpg

Well, I can see the wear, but obviously you have other troubles.

Is there still play in the steering? Have someone manipulate the steering wheel while you look for play.

Did you try swapping tires front to rear?

Play in bearings?

Jack one wheel, leaving the other on the ground. Grasp at 9 & 3 and check for ANY play. A "thunk-thunk" means something is loose, and loose will mean vibration. Since it's intermitant, I'd guess the drag link or tie rod ends. Not enough to just look, you must push on them to check. ANY movement sideways at a ball joint in the steering means replacement time.

Peter