Did you get your suspension looked at? I dont know much about your problem, but I know they have complicated suspension setups and anything in there that is worn out can make it vibrate even with the littlest amount of free movement... thrust arms, steering box, draglinks, ball joints, etc... with it being a quattro, the rear driveline should be balanced but I have a hard time beleiving that could be it unless you hit something and dented it. Does it make any noises, squeeking? I had a CV axle go bad in an old car and that thing vibrated bad at speeds above 45... just my thoughts.

 

no i haven't had my suspension checked, that is my next step. Also another thing i can add to this whole thing. When I make a u turn my car vibrates like a shutter through the whole car. Its different then the one going down the road. I called Audi about it and they said it was normal for a quattro especially w/ new tires because only two wheels are turning but all four are spinning.
Thanks cdemp for writing honestly i'll take anything at this point. I very well could be the CV axle. Whats so crazy is that I can really only feel the vibration in my butt and back which means its in the back but my mechanic said that all four were "thrashing" in the air when on the lift. Could the quattro be causing the vibration? HELP

 

hmmm, kind of a mystery. I would guess its something to do with the Quattro in the back. The rear transaxle mount broke on my Quattro and it was vibrating. I would get it in the air and check the all the mounts. You could even get under it and start shaking things and stuff to see if anything moves when it shouldnt, its kind of a rediculous way to diagnose- but it has worked for me! When it turns it gets worse, so I would maybe think about front CV axles if it was in the front or possibly a gear in the gearbox.... it means that it gets worse as the power is transfered to different tires....

 

so for all of you that are dieing to know what happens next. Today I took all four wheels off my car and then put them under the car to support it while still in the air. I ran the car w/ no wheels on it and I went around and felt each CV drive shaft while it was spinning ( I had a friend sit in the car and give it some gas). I started the inspection on the passenger side. And was disappointed when i didn't see anything. Then i went to the drivers side and in the rear I could see that the driveshaft itself wasn't spinning in perfect circle. I put my hand around it and it gave me the same vibration I feel when i'm driving. So then i went to the front of the driver side and did the same thing and it too gave me a vibration. PRAISE JESUS at least now I know what the problem is. I immediately picked up the phone and called my local mechanic that I know. He told me that remanufactured would run me about 150 a piece. So it "looks" like we've found the solution to mine but I def. won't know until its done. I don't even want to imagine was a new CV joint would cost from Audi. I'm guessing 300 a piece plus labor. Thats why I'm going local.

 

Its hard to imagine that you have two bad axles that are causing the problems. I hope at least this fixes your problem anyway. Keep us informed on the progress and I hope this will be the end of the vibrations for good. The shuddering you feel on a U turn is normal. Mine does the same thing. I have heard that maybe a fluid change in the rear differential with a stabilizer added might lessen that problem. I haven't tried that yet.

Good Luck...

 

Yea I kinda raised an eyebrow at my car for having two bad axles but time will tell. I certainly hope so anyway. The crazy part is that the back axle became noticeable only AFTER i had new tires put on. Yes, it could be possible that the new tires are much gripper since the old ones i took off were bald. Also I bought the car w/ some vibration in the steering wheel which i'm guessing is the driver front axle. thanks again for all yalls help and i will def. keep you posted.

 

the update....i picked up my car today from the local mechanic. He replaced the cv axle that seemed the worst to him. He was not able to find the part....and he told me that the part from Audi would cost me 600 bucks per bad axle. So i said i would order it. I got it for about a hundred bucks. The rear one is VERY hard to find so I just ordered the front one and said we would try that first. Well....it didn't fix it. I also found this link that in some ways depicts my vibration perfectly. http://www.blauparts.com/audi/audi_c...oint_kit.shtml
So the next step it seems is to replace the back one that I also noticed vibrated. If any of you have any ideas please chime in.

 

I'm also wondering if it could also be the rear differential? Could a bad bearing be causing this?

 

I've never seen a bad bearing cause a vibration unless it was ready to fall apart. So I would doubt very much if that would apply to your situation. Mostly a bad bearing on anything starts as a growling noise. I'm still thinking it has something to do with the tires.
When you go slow, maybe 5 Mph or so do you feel any bumps or shifting like a belt in the tire has broke or shifted? Belts in the tires have been known to shift especially after hitting a pothole or something of the like. Any back and forth motion when at a very slow speed?
And try it first before you answer. 3 to 5 Mph in forward direction first then try it in each direction.

Good Luck...

 

Ok so it looks like its time for an update. I finally after spending well over 600 dollars decided to take it to Audi. I was tired of messing with the thing. Audi in 5 mins. told me what was wrong. They told me I had an out of round tire. This goes to show that the two other tire shops weren't going their job or using really old balancing technology. So the place that sold me the tires gave me a free set. I haven't had them installed yet due to other issues with my car (my car has decided it would like to live at audi). I will give another update shortly.