I know it might sound crazy, but I'm with Major Mike. I once had a noise that I had narrowed down to the tcase. I removed the tcase (not disconnecting the rear ujoint) and had a transmission shop go through it. They declared it quite healthy for it's miles and told me to look elsewhere. Upon re instllation of the tcase, I moved the shaft just right and noticed something. The rear ujoint was SHOT! Somehow the driveshaft transmitted the sound that ujoint was making. Myself and another observer were sure the noice was coming from the tcase......
Check those ujoints again!
Dave
Dave, N9LOV
Member #242
Dave's Diesels:
Sold June, 07 '82 1/2 ton 4X4;340k miles
'97 2 Dr Tahoe, Intercooled,
Kennedy ECM, 4" Exhaust
'02 GMC