Alright, so changing gear oil didn't really do much. The truck feels livelier but still has the whine and shuddering in turns.

After doing some probing I noticed two things I didn't quite take into account before... not sure if that helps:
1. The whine comes through the gear shifter and can almost be felt if I have my hand resting on the shifter. Transfer Case maybe?


2. The shuddering is not constant... it's more timed, occuring as the turn is made almost as if something is turning and everytime it passes a particular spot it shudders - yeah, I know, sounds like pinion gear related.. crap

P.S.
Etl: I did pull the fuse - no change.
Tom: the tranny shop I thought was pretty unbiased but if you have another specialist I'd be willing to talk to them!