pewter82

Just got the car back from my bumper mod/respray a few weeks ago. the car sat in the shop for several months, being moved ever so often to make room for other work. I brought the car home several weeks ago and its sat in the garage.
I take it out today to run it, and I get a pretty good shake in the steering wheel at around 60mph. I back off the speed and it goes away. I took the car back around my neighborhood and ran it pretty hard up through 60 mph several times, and the shake was intermit.
I was told the PPI showed a leaking front diff. Is this a sign of a failing diff or could it be just flat spots in the tires or a simple balance problem???


TIS

Jason

96 C4S

MarkD

It didn't do this before the body shop?
Since it sat for a bit, my first thought would be flat spotted tires but that would be felt at lower speeds also.
Could be wheel out of balance... it is worth trying that first.

If it is not a wheel and it starts around 50-60mph and goes away above that speed, then likely control arm bushings. I'd get the car in the air and check them.

Chris Walrod makes polyurethane replacement bushings at a very reasonable cost.

pewter82

I'll have them checked, thanks.

jason

Barney1

Hea Mark, Do the Turbo control arm bushings also have that same affect? I have the same problem. I have had the tires re-balanced 2 times and that is not the problem. My car only has 40k on it..No flat spots as I drive the car as much as I can. Only at 55-60 mph. ITS KILLING ME..

pewter82

It seem that under hard acceleration the shake is more noticable, cruising up thru 60mph, the shake is more subdue'd...


jason

Uber 911

If its kicking in at 60mph its balance, no question. I had a the same problem on a 964, had the wheels balanced 'professionally' never came back.

993Porsche

I had this same problem. I solved it by drilling out the rust and dirt from the rotor holes. Then hosing it down. Since it sat for a while, that could be the problem.


Ken

MarkD

Mike, yeah, same bushings, same possible issue.

Barney1

I had the wheels Road Force balanced twice and all is ok. Brand new wheels and tires and brake rotors..

SKM

Drive it for a few hundred miles. If it is flat-spotting, it will likely disappear. I've seen that before. As I recall, the shake from flat-spotting did mostly occur over 60 mph or so.

cabrio993

+993 on the flat spotting. More so if you have 18" wheels.

If you had bad bushings or bad wheel balance, you'd have noticed before you took it to the shop.

Mine does the same thing after sits for a week or so. It goes away after a few miles and the tires warm up.

murfysflaw

I have that, a bit lower speeds, when my car sits for a week or more. Mine goes away quickly once it warms up, but I also suspect minor flat spotting from sitting.

chris walrod

I get this too after the car sits for a few weeks. Goes away after ten or so miles.

zone5

I have the same problem -- car's steering wheel shakes like a washer during the spin cycle from 57-62 mph. It doesn't improve after driving 10 miles. I just got back from Costco where I bought the S-03's on the carand had the tires rebalanced, and if anything the wheel shake is worse. Car is very smooth above 70 mph. I guess I'll have to go to a store that has one of these? http://www.gsp9700.com/

Back in the mid-90s I had a 300ZX Twin Turbo and had the same problem -- no one could balance the freaking front tires well enough and the wheel shook at 60 mph just like the current car. Finally, I brought the car to a shop which balanced the tires by hand, while ON THE CAR!! They spun them up with some kind of machine and when they were done, the ride was totally smooth, just awesome.

I was going to go back to that shop, however I have a C4 and I didn't want to risk having the front tires forcibly/passively spun because I thought it might damage the 4 wheel drive mechanism.

swftiii

All comments are great. I had a similar issur and after trying all the things you all mentioned it ended up being a wheel bearing.

Just keep that in mind too.

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