Hello,

I have about 11,500 miles on my 01 coupe. The front tires have a ton of tread left but are cupped. Has anyone been successful in getting either new tires put on under warranty or an alignment under warranty...or both? Just wondering if GM will do anything for us with this common problem.

Thanks for any advice
Kevin

 

Maybe front cupped tires isn't as common as I thought?

 

I'd like to help but I'm afraid I don't understand the term "cupped". I've never heard it used on this side of the pond. Does this mean they are worn on both outside edges but good in the centre, or worn in the middle but good elsewhere, or something else ?

 

I noticed that the front tires on my 99 Coupe were starting to get cupped at about 9,000 miles. I was told that it was a common problem, due to the factory alignment. I have since had it aligned.


[Modified by Tom/99, 8:44 AM 1/5/2003]

 

I know the cupping is due to the factory camber settings - But I am interested in knowing if anyone has had luck in getting GM to pay for an alignment or possibly new tires due to ther cupping. It sounds like most of you just had it realigned on your own though.

Thanks for the replies

 

GM replaced my front tires (cupped at about 9000miles) Gave me a new alignment all under warranty. New tires did same thing after another 10000 miles.

 

Front tire cupping is normal wear for GM alignment specs. When I got my C5 in 97, no one knew this and I got my front tires replaced twice, but now that it is more or less common knowledge, it may be harder to get any help. Alignments are easy to get up to 7500 miles, but after that it may be hard to get a warranty alignment.
A new alignment won't help any if you use the GM specs., so you might as well leave it where it is unless you take in your own specs. to put on the car.
Basically you want to get rid of the neg. camber, front & rear to even out the tire wear. If you do this you'll still be within GM allowable specs.

 

Alanh,

I agree.

 

Kevin, I've read in one of the Vette Mags (can't remember which one) that GM set those specs (i.e. neg camber in the front tires) to improve handling around corners, etc. They have found that if you drive more on the highway than in the city/country (i.e. less curves and less hard cornering) that you will have a tendancy to have the "cupping." I don't know if that's true or not...I only have about 5,800 miles on mine and I only do city/country driving with mine (pleasure only). But I will keep an eye on it and see what happens. Mark
BTW, I maintain my tire pressure at 32PSI (cold) --two lbs. above the recommended tire pressure.


[Modified by Mark S., 11:59 AM 1/6/2003]

 

All I can offer is good luck. Ours was in a minor "fender bender" some time ago; no frame damage - all cosmetic they said. The hit occurred on the right front. Before I would take the car back, I wanted the alignment checked. Body shop (local dealer) said no problem; they planned on having it aligned anyway.

Picked up the car and verified that the alignment was checked. Our insurance wasn't charged the cost for a full alignment; alignment was ok they said - didn't have to adjust anything.

Now, several thousand miles later, our car is in (different dealer) for a re-ring. When the front wheels were removed, the right front inside was worn almost to the cords. The left was cupped slightly on the inside edge only. Pretty obvious that the alignment was off. No go at the dealer; too many miles on it they said :mad :mad After all, I could have hit something and caused the alignment to shift; if I had noticed a problem after about 3-4k miles on it, then they would have "helped me out":bs

So, in our case, we just forked out $512 for some Michelin Pilot Sports. I've resigned myself to this, but Donna is still :mad :mad I can't even talk to her about the new tires


[Modified by John Nowak PE, 2:17 PM 1/6/2003]

 

There are two kinds of cupped: A) inside and outside edges worn with center remaining, and B) numerous scalloped and uneven wear on one or both edges. A is indicitive of either pressure or alignment and agressive driving; B is indicative of shocks and/or suspension problems like worn ball joints or worn bushings. Your car is too young to indicate B.

You may be able to get more wear on your next set of tires by inflating the fronts to a higher pressure.

 

."Cupped" usually refers to only one edge of the tire (inside or outside) being worn greater than the other. Cupping is mostly due to alignment where as air pressure will affect the middle of the tire or both outside edges equally as you stated.

 

have the front end guy "stand" the camber straight up and down, 0 degrees, not the .25 degree negative GM specs for better handling. this was printed in the fall 2002 corvette quarterly. running 35# of air cold also helps :chevy
[Modified by clem zahrobsky, 7:48 PM 1/6/2003]

 

Thanks for all the replies. I have been running 32psi to help avoid this problem. I guess I will boost it up to 35psi if I can't get the dealer to replace - Which it doesn't sound like I am going to be able to do.

 

Cupping is generally caused by a combination of alignment + tire balance + tire pressure - if you get all three correct, your cupping should stop -

On non vettes you should also rotate the tires ..

:cool: :cheers: :smash: :seeya

 

Please see other post on 98 Nassau Blue tire wear.. Set camber to zero,, toe in about 1/16 it should wear even on the front.. same for rear.. Might affect really hard turn performance., but they don't give tires away.. vettdvr :iagree:

 

[QUOTE].B) numerous scalloped and uneven wear on one or both edges. ; B is indicative of shocks and/or suspension problems like worn ball joints or worn bushings. Your car is too young to indicate B.[QUOTE]

OR you could be lowered too much..:yesnod: ..just noticed this cupping this weekend when I raised my car back up about 1/4" to get some suspension back