Pro Street

Went to Colorado Springs,CO. and drove 1188 miles and noticed I picked up a front end vibration at 75 to 90 mph.Had front and rear alignment done after I lowered car 6500 miles ago.Also noticed the front tires are cupping and feathering on the inside and outside.I think I have a balance problem and a wheel alignment problem.My question is, is it toed in or out or caster or camber?
Has anyone had there tires do this?What was the fix?Thanks for any help!

65GGvert

Sounds like too low on the air pressure.

Pro Street

Front tire pressure on the DIC showed 30 to 33 cold to hot.

65GGvert

I don't see how the caster or camber could wear both edges. One or the other. I guess tow could scrub both, but you said cupping too. The only thing I've seen cupping both edges is tire pressure. Check it with a gauge. Is it just the front and is it both front tires?

Pro Street

Rear tires are great and no wear.The car just hit 13000 miles.It has a wap,wap wap noise on smooth roads (changes with how fast you are going) and a vibration at 70 and above,but the noise is at lower speeds also.

65GGvert

Once they cup, you're doomed. There's no way to correct the cupping on a vette. You can't rotate. If it's inside and outside, swapping tires around on front won't help. To get them quiet again, you'll have to replace. I have to think low pressure caused the start. Maybe someone with more tire experience can help, but I've had it many times on other cars. My ex never checked pressure and the rear tires cupped badly on her front wheel drive cars. Double check the pressure with a gauge and see if the DIC is matching. It would be in your best interest to have the alignment checked again. If the tires were considerably too narrow for the wheel, it could pull in and put pressure on the edges. I'm out of ideas. I'm still betting low pressure at some time or other started the cupping.

Pro Street

Car has not moved since yesterday,garage is 78°and checked all tires with tire gauge and they are all at 30.

02gt350

have runflats? sounds liek those pieces of **** to me. I went through 2 new sets up front on mine. When I took it to the stealership, they told me "its normal, just dont drive so fast" I had 2 alignments doen and every suspension component checked. Since then I bought new non runflats and have had 0 trouble in 10k miles. Either make the dealer pay for your tires, or get rid of them

65GGvert

I've had runflats on two C5's and have never had cupping. There are thousands out there, you decide. You didn't mention runflats, but you did mention lowering, maybe some issue with that?

Pro Street

Yes they are runflats.They are the tires that came on the car new.
Car has 13000 miles now.

mrm1149

One of your issues sounds like a balance problem.......have them checked on a Hunter Roadforce machine . The Roadforce machine will reveal the problem hopefully.

TEXHAWK0

I always thought that cupping was the result of the tire bouncing due to out of round or out of balance..

Janster

Bad shocks???

65GGvert

Surely if your balance is off enough or shocks bad enough to cup your tires, you've noticed it in your steering wheel before now. Check all those things and report back what you find.

Pro Street

Well I guess they are closed for the 4th.Tried to call 3 times today and no answer.So when I can get it in I will post what we find.

Olfart

While at my dealer recently, a technician pointed out cupping on both of my run-flat front tires, on the inside and outside. I followed his recommendation to have the alignment checked, but found no issues there.

These are the original Goodyear Eagle F1 Supercar tires, and I want to make sure the problem is with the tire, NOT the car before I replace the tires.

I've checked the pressures with a gauge several times to insure the DIC is accurate, so I don't think this is an under inflation situation.

Any suggestions or words of encouragement are appreciated!

Pro Street

Car is fixed!
Took it to a place that has all Hunter stuff.(Mom and Pop and they have 2 vettes)
They pulled the front wheels and tires to balance them on a Hunter Road Force balancer.The right front was out bad and the left was out just a little.So that fixed the vibration!Then they did a 4 wheel alignment and the caster and camber was ok front and rear.But the toe was out bad on the front and the rear was out a little.They set toe and the car drives like new!!!
Now I am ready for a rod trip!
I think the next trip is Corvette Weekend at Eureka Springs AR.
SeeYa there!

R Mackow

I lowered my C5 all the way on the stock bolts, camber set at -1.5 front and -1.0 rear for autoxing, put in Bilstein Sports(FE4), have never had a cupping issue. got rid of the EMT about 18k ago.
I run BFG KDs on one set of wheels, GY GS-D3s on another, Kumho V710s on another and Hoosier A6s.. no cupping issues.

T VETTE

You may want to look into a shop who can skim the cups off the tires. This is sort of old school but if the tires are new and have lots of tread left it may help. I did it to a couple on the front of a Camry and it saved the tires. You will only loose the cup peaks and a little tread. Cost $35 per tire, done on the car. Just a thought.....................

mrm1149

That's great to hear Pro Street! Sounds like you found a great shop. I love these guys who blame every fart and wrinkle on the runflats or any tire for that matter. Alignment and balance and air pressure have everything to do with even wear and a good ride...........