I am seeking some help with a violent front end vibration that my mechanic (and I) can't seem to solve.

The symptoms:
Vibration at speeds > 100 Km/hr, when turning left only (maybe 0.1 G). Disappears when brake is applied (even when speed is maintained with accelerator). No vibration what so ever unless above. This is violent as when going over large tar strips.

What has been done/checked:
front bearings replaced, all bushings, ball joints , shocks, springs etc. checked and appear correct. Axels also rebuilt. All to no avail. The wheels are not a factor as the symptom appears with other wheels.

I'm at a total loss. It must be some thing small, but what?? I can't afford to take apart the car on a fishing exposition.

Any thoughts would be greatly welcomed.

Thanks,

Steve
'88 Turbo S
244 K Km

 

When you tried it with other wheels, did you try it with other tires as well? If not, then it could very well be a belt seperation.

 

Is it consistant, does it always hit at the same speed? Is in only on one side? Or do both wheels suddenly go nuts..

Take it to another mechanic and have him check EVERYTHING again. I suspect a ball joint, tie rod end or other front end part. The ball joints are hard to check. Don't forget the inner tie rod ends. They are under the bellows on the steering rack. Shocks can do this as well.

Good luck on the search.

 

Since you didn't say so, thought I'd ask if you'd checked the rotors for "true", no runout, etc? I'm curious as to why it would go away when the brakes were applied----???? Just wondering if rotors could be warped.
Let us know the ultimate answer.

 

Tried balancing the wheels while on the car?
The wheel nut with lock has an different weight than the others. This is normally not taken into account while balancing.

If you run wheels with non standard offset, has the alignment been ajusted to compensate?
These cars have an negative "lenkrolradius".
When using bigger offsets the negative might become zero or positive, causing all kinds of funny things like vibrations.
TakeCare

 

Does this shaking only occur in left-hand turns? Does it also only happen with light steering input? That is, it doesn't occur if you're cranking in the steering and going fast around a corner?

If so, it sounds like a loose and worn-out right ball-joint...