AndyK

Sometimes, when making a sharp left, and hitting the gas, I get a grinding, vibration type noise--I think from the right rear. Doesn't happen all the time though.

Could it be CV joints? Or something else?

Z-man

Andy -
Yep - could be CV joints - when was the last time they were looked at?

Could also be a rear wheel bearing. Slight chance. I would check the CV joints first. Check the condition of the CV joint boots for cracks and tears.

-Z.

AndyK

Not sure if these are originals or not--bet they are though! How tough a repair is it to replace the rear half-axels--if that's what I need??

pcarfan944

Mine does the same thing, only when turning left while accelerating except the noise is coming from the front somewhere. I've been wondering about it for a while so i'm glad you asked.

____
Pat
86 944
95 Audi 90 CS

Jaay87S

I can attest to the same problem too... guess it's somewhat common. Anyone know how critical it is to address this problem?

Dal Heger

Actually I found it to be the tire rubbing on the inside of the fenderwell. The suspension is soft enough that it happens from time to time, especially if you fitted a bit wider than standard tires.

Check the simple things first.

Doubt that it would be the CV's - they click
Doubt that it would be the bearing - that sounds different too. You can tell if it's a bearing by doing a nice little slalom with the car, the sound will change as you load/unload the bearing in question.

Dal.

theiceman

Make sure the dust sheild is not too close to the rotors, I concur on checking the the simple things first.

Half axles are easy ... just messy. you can get a boot kit which includes boot grease and clips, but unless you are really cash strapped replace the cv joint and be done with it ( ps mine clicked )

AndyK

I would just buy new (or rebuilt) half-axles...no way I'm killing myself ripping the old ones apart!

Tires are stock width, and I doubt my new Koni yellow's are letting the tire hit the body...?

Dal Heger

I don't, happens to mine. Stock torsion bar == SOFT.

Seriously doubt that it's the halfshafts.

But take my advice and use your own judgement.

Dal.

pcarfan944

This might not make sense....but with my car, I notice it does it a lot more once i've been driving a bit and everything is warmed up, and it really only makes the grinding sound between 2800-3200 rpm.

_____
Pat
86 944
95 Audi 90 CS

gtroth

Yeah, CV's thump at a once around frequency of the rear wheel in my experience (i.e. the one time I had one quit). Left side would more likely be the one to go first, I think, due to exhaust heat.

If you replace the axles anyway, it's not too difficult. Use PB blaster, clean out the socket heads real good, wake up the bolts, and use a good cheesehead tool. And torque them right when reinstalling.

Oddjob

Grinding noises during turning are more commonly wheel bearings or exhaust rubbing. Tire rubbing can also give somewhat of a grinding feel or sound. Its more typical for CV joints to tick or give a rythmic thumping than a grinding noise/feel.

AndyK

Hmmm. It does sound like the exhaust vibrating, when it does happen. Could be a heat shield or something like that. It's not a ticking sound--more like a vibration.

Chris_924s

I had a grinding from the front at a 1/4-1/3 wheel turn sweeping right. 15-35 mph only.
It was the front wheel bearings.
Check for excessive front wheel movement while in the air.

Exhausts rattle, not grind. (mine was at 2900rpm.) That noise made me frikkin crazy til I got the damn rattle fixed.

HTH

Oddjob

Depends on where the exhaust is rubbing. It rattles if something is loose or if hitting something that is not solid (like a heat shield).

But I had my exhaust (down pipe section of a turbo exhaust) rub on the control arm caster mounting point only during hard right hand turns while under acceleration (combination of the body flex and the motor mount deflection while under load). The exhaust is very solidly bolted in place at that point, and it was pushing against the solid frame of the car - sounded very similar to a bad wheel bearing.