grinding/whining sound in the rear end!
 

Need help!
I have a 2000 Audi A4 2.8 liter Quattro. Recently I have been hearing a sound
coming from the rear end. Everytime I turn, left or right, I hear a grinding sound and I feel vibrations coming from the rear. I thought it was a wheel bearing but I replaced it and it still makes the sound. Can anyone help me?
When I look at the rear Diff I can see fluid or grease on each side of the differential housing right where the cv axles come out of the rear end. Also, when driving, mostly at higher speeds, I can hear a faint whining sound behind me. Do I need another wheel bearing? Or is it something else? Comments appreciated! Thanks