My rear end is driving me nutz!! It sounds like I have mud tires on the back. I just put new tires on and the sound is the same?? Has anyone had a sound like this before? It does not sound like bad bearings or a bad gear. I also just changed the u joints and had the drive shaft balanced, it did not cure the problem at all.

 

Probably axle bearings (which means, axles)

 

I get the same noise with my new gear change to 4.10 in a 9 bolt. Had the axles changed with new pressed on bearing to the axles and still the same. I think it is someti=hing to do with the gears making that noise and from what I've been told, it is normal.

 

I would also guess axle bearings, however you can probably just install some 'repair bearings', that will ride on an untouched part of the axle...saving your existing axle's.

 

It could be axle bearings. but it could also be pinion/carrier bearings as well. To check it, get it up in the air with the wheels of the ground and put it in gear while running. Take a long screwdriver or pry bar and put the metal end to each axle next to the wheels and the handle part to your ear to listen for wheel bearings. Next, do the same around the carrier right behind the pinion yolk and right on the carrier housing. wherever the sound is loudest is what bearing needs to be replaced. Only check this if the noise changes with engine speed/tire speed. If it is constant and only at a certain rpm or mph, it could be gear whine much like what mcbchild was talking about.