Mechanic changed the oil today; it was down a third and very dirty. For such an important function, the unit sure doesn't take much oil - at most a quart. Noise still there, but maybe reduced slightly. Looks like I'm the victim of lube places not checking the differential even though they say they c...

Recently replaced both read wheel bearings on 05 AWD: $1500 +.

Now comes a whineing sound from the rear end, confirmed coming from differential. I'm getting tired (and poor) with these repairs on a 7-year-old car with less than 87,000 miles on it. Are these common issues?