Chevrolet Repair: Differential on 89 2500 Chevy Suburban 4x4, chevy suburban, chevy pickup

Question
Hi,
I recently drove my 1989 3/4 ton 4x4 suburban from Los Angeles to Oklahoma.  During that time, the rearend started whining.  It's pretty loud, and sounds the worst after I accellerate to about 40mph then back off the pedal to maintain that speed.  I have found a 92 14 bolt rear from a 3/4 ton chevy pickup and wonder if I should replace mine with that and if it will fit without mods.  Both are 4.10 gearing.  Is there anything I should check, and while I'm pretty mechanically inclined, I've never done a diff swap...is it really hard / technical?  It isn't slipping at all, but does "clunk" when the truck is cold and I shift into reverse.

Answer
Hey,

 Sounds like you ahve a bad pinion bearing which may have been caused by a bad ujoint.  Check the lash of the diff at the rear input yoke and then decide what to do.  If you keep the one diff in the truck and fix it you will be better off then putting used one in that has a problem.

w