When I'm in the mud and the TT4 starts to do its thing, there is alot of resistance in the drivetrain and it sounds like grinding. The sound is very similar to that of a wheel bearing going. When its not muddy and I'm on the highway there is no noise. If I were to be ultra sensitive to the situation there might be a little more noise than usual when driving on the highway.

I did notice today that one of my upper control arm mounts was loose and also the half shaft bolt in the hub was loose. i've tightened them and the noise is still there.

I'm thinking differential or T-case now.

Crap.