I pickup a 99 Audi 2.8 Quattro from a auction. So far I have fixed the headlights, the breather hose was replaced, replaced both tie-rod ends, changed the oil and the filter. I finally drove it, engine wise it sounds and run really good. But I'm hearing a grinding noise coming from the rear. So I assumed that it is the rear wheel bearing on the drivers side. My concern is could the grinding be coming from the rear differential? If so how hard is it to replace? Keep in mind I'm a Chevy gear head and know my way around a vehicle mechanically (American that is). How often does the rear diff go bad?

Rob

 

I dont know about the diff, but it's probably a wheel bearing. While driving steer the car from side to side to shift the weight on and off each wheel. If the sound changes intensity while you're doing that you can figure out if it's coming from only one side. If it does it's the bearing.

 

Most likely wheel bearing, which is a common failure on our cars (And a bitch to change).

Rear diff is very strong and I never hear of any issues.

 

Thanks Guys, I've already started taking it apart. A few more bolts and I'll have it out. Then it 's off to the shop to have the new bearing press fitted.

Rob

 

Have it aligned when you're done

 

That is the plan

Rob