Please help me figure out steering vibration!!!

[FirstGen]

So belt seperation seems to be the vote. I just don't see how that could be the problem if the last set of tires caused the same vibration...

What causes belt seperation?

[nhromyak]

age.

I missed it where both sets (all four?) were giving you the vibration.

It could also be shocks...(and a lot of other things).

Get the rims checked or check them for run-out and cracks...

[schleg79]

Check the front tires for "cupping". I've had this problem on two separate cars now (neither were P-cars), with the exact same symptoms you describe.

Normally, it will be found on the inside edge of the tread. It's often hard to see, better to feel for it. If cupping exists, you'll have a series of tiny raised and lowered areas, equally spaced - like little "cups". Cupping is caused by worn ball joints and/or alignment issues causing irregular tire wear, so I'm told.

Hope this helps.

[Jon Merck]

Originally posted by FirstGen
No I have not. Where is it located and I will check to see if it is in good shape. I have a Nardi wheel with a quick release. It feels solid under normal circumstances though...

It is on the steering shaft directly under your steering wheel. The upgraded ones are steel. I think from a 928.

[dentist90]

Originally posted by FirstGen
So belt seperation seems to be the vote. I just don't see how that could be the problem if the last set of tires caused the same vibration...

What causes belt seperation?

Tread belt seperation can be a factory flaw, but I believe comes more often from impacts (eg potholes and curbs). Underinflation with overheating can also damage sidewall and belts. Thing is the tire should eventually be measureably out of round after awhile. I didn't mention tread seperation but I did mention a quick check for tire trueness. I believe you mentioned this problem occurred with the old set of tires so I think we are barking up the wrong tree as far as tire balance is concerned. Some of these suspension bushings are hard to verify unless the car is up in the air and the weight is off them. A VERY slight wobble in a front wheel will be felt thru the steering wheel even though things look tight on the ground. Keep us posted!

[nhromyak]

Are you "checking" this vibration on the same stretch of road????

It may be the road... try another one...

I have this weird thumping that I can only feel/hear in my 911. I don't feel it in my Isuzu, Mitsubishu or Chevy.

Good luck.

[FirstGen]

My goal this week is to put the car back on a lift and to check all four hubs with a dial indicator for true ness and to check each tire for run-out.

I will post exactly what I find with these measurements.