rear axle noise

[afpj]

Hi, another newbie question. My search of the forum didn't quite return what I was looking for so here it goes:
02 Yukon 5.3 flex, 4wd, 115k, all stock. Started getting low pitched whine when making right turn, but only after having driven it on freeway for a little. ONLY right turn causes the noise and it sounds like it's from the rear to my surprise, not front wheel. Since it's ONLY with a right hard turn, wondering if it's the rear diff, wheel bearing, brake assembly? I don't know enough about these ltd slip diffs, but I thought it would be a left AND right turn noise if it was the rear diff?? No noise going straight at any speed...too much wind noise above 75 so wouldn't hear it anyway.
ANy insights much appreciated. Thanks for a great forum and forum members

 

[axekick]

First jack up the rear and try to wriggle the wheels. If one of them has any play then it is a wheel bearing. I'm not suggesting that that's a common problem on these cause I don't know what the common problems are but that's the first thing I would check in trying to figure out the problem.

I really don't think there are too many mechanics on this forum. I find useful reviews on mods and stuff but not much mechanical knowledge. I used to hang out at a Toyota truck forum and there was always an answer to a mechanical question that you could count on but I think its because those old pickups were abused, broken and repaired on a regular basis. I don't read about too many problems with our Tahoes.

 

[afpj]

Update for anyone who might have similar issues: Finally took it in to a local mechanic. Wheel bearings OK. THe noise is from the rear diff. It was resolved by a fluid change. Last fluid change about 25k miles ago, but I don't recall adding a limited slip lubricant. The mechanic I used this time says this 2002 yukon 4wd with ltd slip rear needs to add the lubricant in addition to the synthetic oil. Never heard of this lubricant before, but it fixed the whirring noise. Anyone heard of this added lubricant before? In any case, problem solved.