I posted here a few weeks ago about a continuing problem I am having with new tires. Back in August I put a new set of Hankook V12's on my box. I had them balanced 3 times and still had vibration in the steering wheel. The last time I had them balanced it was a road force balance. I purchased the tires from Discount Tire on line. I got some advice by a local race mechanic that puts tires on all kinds of race cars including Porsche. He recommended that I get an all season tire because they would not get flat spots from sitting and would run out just fine on my car. With his recommendation I traded my Hancook V12's for Yokahama ADVAN S 4'S. Very nice Ultra High perfromance all season tire.
So, here is the issue. I had the new tires mounted and installed by a discount tire local install center. They were road force balance with me watching. All well within specs. Also checked the alignment and it too was within specs. Rims were very straight. The tires still vibrate, shaking the steering wheel. It happens every morning when I leave for work and is very pronounced at 35 to 40 mph. There is no noticible shake or vibration at 25 to 30 mph. It continues to get worse as I gain speed until the tires warm up and then they only vibrate over 70 mph. If I let the car set for a few minutes or an hour it runs out pretty well until I get to over 70 mph but the vibration is till there at 60 mph but almost gone. No shake at 35 to 40 once warmed up. It only happens when it sets overnight. It is in an unheated garage on a cement floor.
Questions are, does anyone have any idea if anything mechanical would cause this condition. My local mechanic want to look at the rear axle. He say's it could cause a vibration similar to a tire balance problem if it was going bad. I think it could be a motor mount. Temperature does not seem to be a factor because I had the same problem in August as I have now in December. Any other ideas what could cause this issue? If I run the car up to 80 mph it does seem to get worse and would not want to drive there for any length of time. Another thing I have noticed is that when I let off the gas at 80 mph and just let the car slow down, the vibration is much less noticable when it gets to 65 or 70 mph. When I give it gas and get back up to 70 or 75 it comes back again.
It is not fun driving my Box under these conditions. Any help would be appreciated.
By the way I have a 2000 base with 55,000 miles.
Threaded Mode
