03 Disco2 85,000 miles

My friend and I totally rebuilt the top end of my motor. When I pulled it out of the shop there was a whining noise that was not there when we started. It seems to be coming from the rear diff and only happens when you let off the gas. It goes away below 5mph or if you apply power. The noise does not go away if you put the truck in neutral while it is rolling and whining. It would also make a significant "clunk" noise when shifting to reverse. I chose to drive the truck like this and the rear diff pinion snapped and destroyed the ring and all the gears.

I installed a used but good rear diff and the whining noise is still there but no "clunk" going to reverse.

The truck had 245/75/16 on the rear and 225/75/16 on the rear. It now has proper tires on it and the noise is still there.

The transfer case was about a liter low. The rear bearings look and feel fine. The transmission sounds and feels fine.

Any ideas?

Thanks,
Chris

 

Did you replace the pinion bearings?
Letting the t/case get that low has hurt it, but to what extent, only time will tell.
What weight gear oil are you using?

 

Using the fluids specified in the Rave manual. Took the truck to see Chris Ray at Ohio Valley Rover Repair. He has been very helpful and where I have been getting parts from. I'm going to swap the diff just in case the one I installed was bad but I think we are both thinking the transfer case is the issue.
Anyone have an 04 transfer case and shift lever assy for sale cheep?