Dealer says "Tire Cupping"

i have a 2009 passat, bought new in june 2009. i brought it in for routine maintenance (oil change & tire rotation). when i left the dealer, the car was noisy from the front end. i brought it back and they told me it was the bearings, they replaced them, and also told me i had tire cupping. the car was still loud in the front on the left side (it’s a newer tire, i already had to replace 2 tires due to our awful roads). i brought it in again, and again they told me it was just cupping. the car has 34k and has been into the dealer for all maintenance (free for the first 36k). i have an appt for march 15th, and was hoping to go in with more knowledge as to why this is happening, or what it actually is. thanks for the help!!

Cupping is usually caused by bad shocks. 36k miles is awfully short for the shocks/struts to be bad.

Tire cupping results from a tire that vibrates at a resonant frequency as it goes down the road. The vibration can be caused by any of several problems, or a combination of problems.

By the time you notice the tire wear pattern, you have already damaged the shock absorber at that wheel. Shocks are designed to cool themselves and put up with a lot of abuse, but they won’t put up with several thousand tiny movements per minute at the same spot in the shock bore for hours on end. The damage to the shock may not be obvious, but it is tough to get the tire to stop vibrating once that shock has been damaged. Hence, subsequent new tires tend cup as well, no matter how carefully you balance them and replace other worn components.

I have an appt 3/15 and want to go in with knowledge (it helps when you’re a woman in a dealership). I know, after 2 times in the shop, something is causing this which they “don’t know”. I appreciate the comments! Thanks!

In just about every place in the US I have lived the locals (espically the ones that don’t get around much) seem to feel it is only their area that suffers for “awful roads” and blame so many car related issues on the road. I find it rather humerous that each local thinks their roads are the worst. In reality there are bad roads “from sea to shining sea”.

How many times were the tires rotated in those 34K miles?

There’s a vast difference between cupping and severe featheredging and sometimes those 2 symptoms are mingled. Make sure which one it is.
Cupping is generally caused by a faulty shock or out of balance tires.
Featheredging is caused by lack of tire rotation or alignment problem; generally toe in or out.

The tires have been rotated every 10k (with the oil change). 2 of the tires had to be replaced already (pot hole and nail). They already replaced the bearings and I think they’re trying not to have to do anything else.

So far, from all the answers, I’m have good comments for the dealer!

I was thinking the same thing. Also, over-inflating your tires can make them bounce around and make the shocks/struts wear out faster.

Probably the alignment is out, specifically the camber for the back wheels. The camber is the wheel being vertical to the ground, if the tire leans one way or the other it will have positive or negative camber. The camber is not adjustable in some cars unless possibly shims or camber bolts are added to make the adjustment. Unfortunately this requires a little time and effort that the dealer may not be willing to do. Have the dealer perform the alignment, and demand to see the print out. You want the camber to be in the middle of the specified range. So hypothetically if the specs are -.5 to +.5 degree, I would not be happy unless its adjusted to within -.2 to +.2 degree. I think a lot of car manufacture alignment specified range for camber is to big, possibly to allow sloppy manufacturing tolerance .

The term “cupping” isfrequently mis-used. “Cupping Wear” is the result of bad shocks or bad balance.

Most likely you have irregular wear - which is caused by misalignment and aggravated by insufficient inflation pressure and insufficient rotation practices.

My experience says that the published alignment tolerances are too wide. Not the target value, but the allowable deviation from that value. I think it ought to be half of what is published.

Put another way, the alignment should be within the inner half of the spec.

You should be aware that even vehicles that do not have a pull can be out of alignment. There are settings where one out of spec condition is offset by another out of spec condition ? typically camber vs toe.

Most of the roads in Florida, especially south of Daytona, are darn smooth.

Tire imbalance in conjunction with failed front shocks/struts are the most common causes…get your NEW tires balanced and new shocks or struts and say bye bye to tire cupping…and allignment wouldnt hert either at new tire time…in fact new tires always dictate an allignment for me…

i have a stupid question… today i went over a speed bump in a parking lot (at slow speed) and the front end squeaked and creaked. it’s still cold out, so is that just normal for this time of year, or could that be shocks, thus resulting in the cupping?

What you heard when you went over the speed bump was probably just dry bushings in the suspension. While annoying, this is not really a problem. This is not likely to be related to tire cupping.

thanks! i didn’t think so, but i thought i’d ask anyway.

So, I recently went to the dealership to have a oil change, mulit-point check, fluids topped off, tires rotated. They called me and said that my tires were cupping. Ironically they mentioned they were having a tire sale and that I should think about getting new tires cause it was going to sound like I was driving over railroad tracks. I said no thanks cause I usually get a second opinion from another auto mechanic. Come to find out that they underinflated my tires significantly. One tire was only at 25 psi. I inflated my tires to proper psi. Should I be concerned that there is something else fishy going on? I don’t usually go to the dealership but I had a coupon so I went this time cause my usual mechanic would have costed the same just for an oil change.

@car_clueless, are the tires making excessive noise?
If not I would drive on, keep them inflated and rotate as the manual recommends.
The coupon gives the dealer a chance to talk you into more work that they can actually make a profit on.

I don’t like the term “cupping”. It is frequently mis-used. “Cupping” is caused by bad shocks or an out of balance condition. But the term is regularly used for wear that is induced by alignment. It is EXTREMELY difficult for the average tech to tell the difference. I prefer the term “irregular wear” as it covers both conditions.

But it is pretty common for folks to also apply the term “cupping” to heel and toe wear - which can be a normal condition.

I think you need to get an alignment. You’ve replaced 2 tire due to bad roads - I take that to mean you had road induced blowouts. Likely that has some bad affects on the alignment.

Assuming causal relationships among variables is one of the most common sources of error in research (and in auto mechanics).

Failed shocks don’t cause cupping any more than a chill causes you to catch a cold. As your body starts to mount defenses against the virus that is attacking it, you feel chilled. You remember feeling chilled just before you felt the cold symptoms, so you conclude that the chill caused the cold. A sweater makes you feel a little better, but it does not prevent the cold.

Similarly, shocks are prematurely destroyed by the same problem that caused the cupping. Replacing the worn shocks will slow down the cupping until your new shocks are destroyed (which they will be soon), but the worn shocks were not the root cause of the problem. They were simply another symptom of the problem.