bk3104

OK, got my Yokohama AVS db's(255/40/17) mounted and balanced(I think) by Direct Tire in Natick(MA) a little over a month ago on my 4.2. They are mounted on my 17x8 AVUS wheels. Prior to this I had Pirelli P7000 Supersports on. I replaced them because they were incredibly noisy. I specifically told them that I was probably a little picky about vibration at any speed and to make sure they were really balanced good. When I got the car back, the vibration I originally had, but that had been fixed with the Pirelli's was back. Pretty much it's from about 45mph on up, although it smooths out a bit on the highway. I've got an appointment to bring it back to Direct Tire and see if they can locate the cause. Anyone know if they are a good place for balancing? Anyone think I may have an issue with the new tires(bought from the Tire Rack) being "out of round" or anything else? I've heard of the Hunter wheel balancing machine and was wondering if anyone knew of a better place to go in the Boston area.

snagitseven

I have come to the conclusion that some A6's (mine is a 2.7T) are extremely sensitive to wheel/tire combinations. I had no probs with my OEM 215/55-16 Contis. Bought Ronal R7 wheels w/Dunlop 235/45-17 and have gone through 3 balancing sessions and two new tires with dynamic balancing and then the Hunter balancer. I finally have it down to a very slight vibration at the same speeds as you. I am beginning to think that this could be the best I'll get until I change tires once again. These cars are WAY too sensitive.
The Hunter is ABSOLUTELY necessary to find out of round wheels or tires. It checks for run-out, wheel/tire matching and assemblies that cannot be properly matched and balanced.
Go to this url
http://www.gsp9700.com
to find the nearest GSP9700 near you.

JP4

ditto....force variance is another factor in the equation.The Hunter site can explain this in detail

STEVE2.7T

My original Contis were good and my S4 wheels with factory balanced Bridgestones were good. Today I am getting new RE730's mounted on the S4 wheels at my dealer. Hopefully they will be perfect as well!!??

JRS4

...2001 S4 and 1994 100S and they were perfect. The guy that runs the place treats his customers well, too. I pay a little more there for tires than I would through Tire Rack but it's worth it for the customer service.

Craig 2.7t

for me. If you do fix this issue with your car please pass on how you've done it. I'm trying to work this through with Audi Service currently. Thanks.

srosie

Par for the "old" course was 37 or 38psi upfront and 33 or 34 back. My happy medium seems to be 34 or 35 upfront and 32 or 33 back. A puzzling issue for sure.

JP4

If there is a slight vibration problem involving the wheels and or tires lowering the pressure will allow the sidewall to be more flexible thus absorbing more of the vibration making a smoother ride on your fanny! ;-)

JP4

There are lots of Hunter balancing machines on the market. The model that can be the most effective in troubleshooting wheel/tire related vibration problems is the GSP9700. That's the one that snagitseven is refering too.

Just thought I'd throw that in because of the way several have been using the term "Hunter" on this thread.

bk3104

Thanks to all that have replied so far, and if you have any more opinions, please don't hesitate to add your $.02 to the pile here. I'll be bringing it back to Direct Tire Tuesday morning and will post an update if anyone is interested. The dealer, believe it or not, fixed the original problem I had with this when I first mounted my Pirelli's. Other than being very loud(due to scalloping), that tire worked very well. These Yoko's are extremely quiet and ride very nice, other than the vibration(it's almost a "hopping" feeling) that is happening again.