01 V70XC AWD binding - unequal tire rotation speeds - front wheel excessive wear

[ElPasoJavaXC]

I have a 2001 Volvo V70XC with 151K miles on it and the front tires are wearing very badly and unevenly. Today the local Firestone mechanics said something is binding in the AWD, causing the tires to rotate at different speeds (we bought the last few sets of tires from Firestone). We had the transmission rebuild by AAMCO at 120K miles I think (I can't remember right now). Do I take it back to AAMCO for them to look at the transmission again or take it to the dealer? I've read several posts now about other owners who have had issues with their rear wheels not working properly with the AWD, but I have not seen any others with front wheel AWD issues. I can't be the only one.

While driving recently I took my hands off the steering wheel and braked. The steering wheel quickly wobbled back and forth from one side to the over as I applied the brakes. Today, while making a slow speed, very sharp U-turn in an empty parking lot it seemed like I could actually feel the difference in tire rotation speed (and hear it as one tire seemed to spin out while the other grabbed the pavement).

This is my wife's car that we got brand new when we lived in Indianpolis and she still loves the feel of the car, but the maintenance issues are starting to annoy me and the safety of the vehicle (especially with unevenly worn front tires) is alarming (not to mention some of the other numerous aging car maintenance issues we continue to encounter).

Chris

[sjonnie]

I have a 2001 Volvo V70XC with 151K miles on it and the front tires are wearing very badly and unevenly. Today the local Firestone mechanics said something is binding in the AWD, causing the tires to rotate at different speeds

This seems extremely implausible. The viscous coupling causes some force transfer between the front and back tires at low speed and feeling this on full lock is perfectly normal but it is not causing your tires to wear unevenly unless you are driving your car round and round in circles in the parking lot. How often have these tires been rotated?

Do I take it back to AAMCO for them to look at the transmission again or take it to the dealer?

Probably neither. I would take it to a different / independent tire and alignment shop and get them to diagnose the problem with your tires / steering. It's also possible that you have a bad tire and the Firestone shop is trying to find a reason not to give you a warranty replacement.

While driving recently I took my hands off the steering wheel and braked. The steering wheel quickly wobbled back and forth from one side to the over as I applied the brakes.

Does it do this if you don't brake? How old are your brake rotors and pads? Is there any pulsing in the brake pedal when you apply the brakes?

[Astro14]

The wobbling wheel under braking sounds like worn suspension parts; bushing, tie rods, ball joints, etc.

Get those checked - they cause tire wear too....

[ElPasoJavaXC]

This seems extremely implausible...I would take it to a different / independent tire and alignment shop and get them to diagnose the problem with your tires / steering. It's also possible that you have a bad tire and the Firestone shop is trying to find a reason not to give you a warranty replacement.

Thank you all for feedback. We did take my wife's car to another Firestone dealer and this second one had no idea why the first gave us the first diagnosis. My wife said he prefaced his comments by saying he did not want to offend her driving in any way, but "how often do you rub the curb when you park?" She had just recently done it (again). We got two new tires, alignment (lifetime paid for on this car a number of years ago so that's why we go back to Firestone), and she got a warning that it's better to park a foot away from the curb than to hit it time and again, thus knocking the wheels out of alignment. On my Honda Pilot I have taken to getting the alignment checked and wheels rotated every 2500 miles to help extend their life and I hope I can encourage my wife to do the same with her car.

Chris