99 LT 4x4 Rear End Whine
 

Alright folks,

I have had a rear end whine on my blazer for quite some time now. It only happens when I let off the gas. It is very loud and sounds like a wheel baring noise I had in my front end not too long ago. Here's the kicker though, If I have it in 4WD, the noise does not happen, but as soon and it's back in 2WD it comes back the next time I let off the gas.

does anyone have any idea what I can can do to fix this myself, or an idea of what to check on?

PLZ HELP!!!

Usually a whining noise when letting off the throttle is a sign of either bad pinion bearings and/or bearing preload being too loose.
Why you don't get it in 4x4 I don't know.

I'm having the exact same sound, but I thought it was happening in the front. Can anyone think of a way of reproducing it with the wheels in the air?

2001 4x4
VIN 1GNCT18WX1K187988