Schnave

My wife reports that her Cayenne suddenly pulls left after years of normal, no pulling. No curb bumps, potholes or other obvious reason for sudden pulling. I drove it and found the left pull was obvious and increased in severity with higher speeds. I scheduled it at local independent German shop. Total miles driven since pulling began is about 100 or so. Tires appear normal with about half tread depth remaining. Tire pressures normal in all tires. I figured it needed an alignment. Cayenne equipped with rear axle steering.

Mechanic swapped front tires and reported that the pull followed the tire — it now pulls right. They recommend two new front tires (22” P-Zero’s for $1063 installed). I had never heard of this but now, after research, understand this is possible. I asked them to perform the alignment and then test drive again. Still awaiting the results.

Has anyone experienced this? Did new tires solve the problem? Could malfunctioning RAS cause this?

Any thoughts appreciated.

Kendo67

Hows the ride height ?

Had a broken front spring on a previous MB and it pulled in the direction of the broken spring as that corner was slightly lower than the other three.

If both tyres are worn by the same amount and worn uniformly across the width then swapping them over shouldn't make any difference ??

Four figures for P Zeros is a bit steep . IMHO.

K

Schnave

Good point. I didn’t notice any ride height issues but wasn’t specifically looking for it. It has air suspension and would expect to get a suspension warning if air spring couldn’t maintain specified height; correct? Of course, that wouldn’t rule out other suspension component failures.

I hope any suspension damage would be discovered during the alignment process (ongoing).

drcollie

I would replace all four tires if they are at half life, myself. Take the two at 5/32's and put them on Facebook Marketplace for sale or keep as spares.

Tires can go funky, but its rare. You could have a bend on that wheel that might be on the inside lip as well. If the fault follows the tire placement, its got to be wheel.tire in some manner.

rdboxster

I have had a tire pull years ago and I think it was due to a belt separation. Haven’t heard of this in newer tires but if it followed the tire probably time for new ones.

retom

I had a similar case a few years ago in a Volvo S90. I don't remember the tire brand, but only replacing them solved the problem with pulling. I think I would also suggest replacing all 4 tires.

Schnave

Very well; thanks to all for the input!

The rear tires have less than 1,000 miles on them due to an unfortunate series of unrepairable flat tires within a few weeks of each other. Therefore, I’ve instructed the mechanic to hold off with the alignment and order just the front tires. I’ll have them installed next week and then reevaluate the steering. Hopefully, no alignment shall be needed.

Once removed, I’ll have a close look inside and out for faults on each of the old tires and report back on this thread.

LDT

Is it possibly a balance issue? Could a balancing weight have fallen off? Might explain the problem shift to right side after swapping front wheels?

ThomasWShea

i have a close friend who is really sensitive to tires or wheels being out of round. he went thru quite few sets of quality tires and quality wheels. and had the dealer look at the car multiple times to try to find something - they said all was fine and it was just the nature of that particular S6 generation. then about 3 weeks before he decided he was selling the car he went back to factory audi wheels and all of a sudden no issues. he believes the issue was that the after market wheels, tho supposedly quality units, were just not as round as the factory wheels. so, food for thought.

also, i know from experience, sometimes u get a bad tire and you will chase your tail. you want a competent shop that can balance everything well. i have always assumed going with a tire w a higher speed rating generally nets you rounder tires. I have also always assumed the very top tire makers have better QA and fewer bad tires that make it into consumer’s hands.

i have also assumed there is some kind of tire distribution hierarchy and that the newest freshest best of the best tires that are the closest to the ideal spec. go to the dealers like porsche. there is a reason costco and discount tire cost less. slightly older tires and ones that are not cream of the crop.

this may not be true, for tires, but my double x worked on the beverage side of the food and beverage industry as a product development scientist, and she told me how when they produce product the freshest best batches that are the closest to product spec went to the top end distributors that distribute to the high end grocery stores, it made sense. it also kind of scared me. also, good brands have less product variability, however, they still manage their product logically and runs of product that aren’t quite as good, though still perfectly fine and within spec, they don’t make it into the tire 1 grocery stores. the runs closest to ideal go out to the top shelf channels.

Felix

If you run your hands back and forth over the tread on the offending side is there anything noticeable? Feathering or scalloping of any kind? Anything on one side and not the other?

PorscheACC

If the tires worked fine before, then put back the tires in the positions before rotation, and then just wait for the tires to wear to change them.

You normally rotate tires to save thread, but in your case, your vehicle wore them unevenly, which means that if you rotate the tires, they will need to be constantly balanced for some time and will wear faster.

When you get new tires, make sure you get a 4-wheel alignment to make sure the new tires will wear correctly.

Similar to when you have staggered tires, you don't rotate side to side if the tires are directional. You just wait for them to wear out and change them.

Many people, and in many countries, they prefer not to rotate the tires because each wheel has peculiarities in their alignment, suspension, steering components, etc. which means that if you rotate them, they will continuously lose balance, will wear faster, and the steering will be uneven until the tires get used to the new positions.

Felix

not sure the OP has actually said that?

What does this even mean?

Woofman

A road force balance by a competent (and patient!) technician likely would have told you what's going on since there's obviously a problem with a tire or wheel. I once had a nagging vibration on a Lexus LS sedan that repeated spin balancing couldn't solve. I finally took the car to the Lexus dealer and asked if they could figure it out. Their Hunter road force balancing machine generated a report that showed exactly where one tire was defective. It was a memorable experience due to the technician being especially enthusiastic about his work and wanting to explain the problem in detail while my eyes glazed over.

PorscheACC

(Correction, you are right.. OP stated stated it happened before swapoing the tires around.. disregard..)


He can check that case, since he stated the problem started after he rotated the tires.. obvious potential issue to start with..

I have 50+ years driving vehicles from motorcycles to high-end vehicles.. All of them suffer similar issues one way or another..

Anybody who has rotated tires where the vehicle alignment was off, or the steering components were worn/bent/off, etc..etc.. knows that when you move that tire to another position, even if you balance that tire, the tire will now wear on the high tread/pressure areas since the tire tread is not even and the tire balance will be lost (needing balancing) until the tread wears to an even tread contact preassure were the balance will remain constant since the overall tread wear is constant..

If you have a tire where the tread has worn unevenly and you have less than half tread left, you are better off performing an alignment, buying new tires, and balancing them.

As anybody who drives high end vehicles at high speed, they will never rotate the tires and ride at high speed because the tires, contact patch, and pressure over area are not the same and can lead to uneven braking and potentially diminished steering stability on wet, snow, etc..

Sure you can do it, but you are just saving a couple of bucks for driving security/safety.

If the tires are getting worn, just replace them instead of playing the cheapo rotation game.. safety wise you are much better off that way since your tire contact patch remains the same.

PorscheACC

Sorry for the last post.. please disregard..

Now, is there any way to check your RAS, too, if tires are not an issue?

Can RASParameters be live monitored/actuated/tested by a Piwis scanner device?