Re: Vibration in front of 4KCSQ

[Robert Houk - SMCC Bos Desktop Hardware <rdh@UrQ.East.Sun.COM>]

   I have developed a bit of vibration in the front end of my quattro.  Just
   put some new TSW evo wheels with D40/M2 dunlop 205/55/15 tires on.  I
   noticed a little bit of vibration, but not TOO noticeable, until I finished
   the suspension upgrade.  Boge turbo gas and Eibach Pro kit shocks all
   around.  Now, at about 58-70 miles per hour( on the speedo, probably out of
   adjustment due to the tire upgrade) there appears a rather pronounced
   vibration that shakes the wheel a bit, and brings a vibration to the front
   end.  After about 75 miles per hour, the vibration is gone.  I know what
   some of you are saying, "Just don't drive less than 75 mph, but sometimes
   current road conditions... 

   Anyway, I have had the wheels checked, and they seem perfect. (I should
   hope so, they are brand new) The tires could be just a little bit "unique"
   shall we say, but I don't think it should be that much to create this
   vibration. I have had the tires checked and rebalanced already once.  Could
   this be a wheel bearing?  They SEEM fine, no play.  What about CV joints? 
   I did noticed some CV grease on the inside of the wheel surface and pulled
   the wheel and checked the boot.  It had been put on a little loose, and
   needed refitting, but could th CV have been damaged?  How does one check
   this?

I have the same problem with my UrQ. I have watched the guy (several times)
balance the new wheels and tires, and they are perfect. On the machine, 
while spinning, there is no side-to-side, up-down, back-and-forth, or any
other non-perfectly-circular movements. And still . . .  The *ONLY* way I
can get the car to not shake/vibrate over about 55-60 is to spring for an
on-car dynamic balance. 

I just mark it off to some little AudiSprite who's taken up residence in
one of the wheel wells . . .

It's not warped rotors [classic gotcha!], bad bearings, or any other
classic component failure. It could be a slightly bent driveshaft or
housing, I guess, and the "balance weight" is just enough to counter-
act the bending moments, but I find that hard to really swallow. Like-
wise, I find it hard to believe that a rotor could be *that* out of
balance . . . but then again, it *is* an Audi . . .

					-RDH