I posted a question a few days ago asking about instructions for rear wheel bearing replacementon my A4. Well now that I have had the wheels off and looked into the vibration I've been hearing, I'm even more confused than I was when I started. I am hearing a vibration that seems like it is coming from the rear passenger wheel when you are riding in the car. At first I thought it was a wheel bearing but there is absolutely no play in the hub (or on any of the other 3 hubs)when you try to move the rear wheel back and forth. So then I thought maybe the outer CV joint but there is nothing visibly wrong with either the inner or the outer boot. The noise becomes noticable between 30 and 40 MPH and gets worse the faster I go. Is it possible for the bearing to be bad without there being any noticable slop in the hub and what else should I look for in the CV joint to tell if it's bad?
Please HELP - otherwise this car may find the bottom of the lake soon!!!!!

 

Have you checked your tires to be sure that they arent out of round? Like a broken radial belt buldging out? That would throw off the ballance. Might be a good idea to take your car in and have the wheels ballanced anyway, its cheap. Can you only hear the vibration or can you feel it too? what year?

 

I can only hear it - You can't feel it.

 

Could be an out of ballance wheel. Usually a bad wheel bearing will "humm". Im betting you just need your wheels ballanced. Try that first.

 

Rotate your tires to be sure. I've had wheel bearings go in the 85-87 4000's, and there was only noise no play that I noticed. I have also had a CV joints go, but it only made noise when turning. My guess is it is a out of balance wheel, a wheel bearing, or a wheel with lugs loose. But I guess it could be anything. ie a bad tire. Hope this helped.

 

I can rotate to see what happens. The tires are not even quite a year old yet. I bought them brand new last April.

 

Sounds like a wheel bearing going. Obviously if the noise follows the tire it is tire noise. If the noise stays in the wheel well itis likely the bearing

In addition, wheel bearing noise is sensitive to direction. If you turn the car to the left while moving at speed the noise will increase. If you turn toward the noise it will decrease in volume

 

i just got done doing a cv replacement on my 01 like 5 minutes ago. i only noticed vibrations in the car when is was going 70-80 miles, but my cv weren't that bad. but unless your boot is broke or you hear clicking i wouldn't bet it's the axle.

 

Wheel bearing play can be tested by trying to wiggle the tire from top to bottom not side to side. It is not a cv problem. Look for a feathering pattern in the tires or else it is a bad wheel bearing. Usually bad wheel bearings make a humming or droning noise that changes pitch as the weight of the car is shifted on to that wheel, where as a tire noise will bee a constant noise at a conatant pitch or will only happen when turning but both the wheel bearing and bad itres can cause the same sound. Grab the tire at the 12 oclock and6 oclock postitions to feel for play in the wheel bearing.

 

Thanks for all your help guys - sounds like a wheel bearing. The noise definitely increased as I turned to the left while going down the road. It just through me off because there wasn't any play in the wheel when I grabbed it (top to bottom) and tried to move it. I had a a friend of mine who is a mechanic come for a ride with me today and he heard the hum and immediately said it was the bearing. Looks like I'll be busy next weekend!! Thanks again - I'll let you know how I make out.