I am a bit of a loss guys. The symptoms included hopping, a grinding noise which matched the tire revolutions and a steady screeching sound at speed. All the issues went away in 2wd with the hubs unlocked and I was able to drive it home at 65mph without any vibrations or unusual sounds.
Pulled the transfer case out and pulled it apart expecting to find it fragged inside like the other couple I wrecked and found next to nothing out of the ordinary. The chain gear on the front output was a bit sloppy on the splines and the crack in the case around the shift detent ball housing was a bit worse than it used to be but that was it. Nothing that would bump, grind or otherwise be in trouble.
Since I have a new case coming tomorrow afternoon and I had it all ripped apart anyways I decided to swap my SYE into the new housing to replace the cracked case half so I left the t-case out and in pieces for the night.
I then figured it had to be something in the front diff. I pulled the outers completely apart right down to the knuckles on both sides and found absolutely nothing wrong. Wheel bearings were properly preloaded and spun smoothly, filled with grease as they should be. Locking hubs move smoothly and show no signs of wear. Axle and driveshaft u-joints as well as the CV center balls are all smooth and tight. Spindle bearings for the axle shafts are good. Kingpins are tight, so is the steering, all the link mounts and all the suspension.
I found the front pinion is a bit loose, but nothing crazy. The gear set still turns smoothly and doesn't make any noise. I started ripping the front cover off and found the oil was a little bit dark and there is definitely some material on the magnets but nothing out of the ordinary. I need to go buy a 1/2" allan key to remove my steering ram to remove the cover all the way and inspect everything inside the front diff.
The rear diff turns freely on both sides, no unusual movement in the wheel bearings. Both lockers engage and disengage properly. My transmission fluid is a little dark, but it shifts fine and I have no problems in 2wd.
I almost hope I find the front gear set is fragged tomorrow, because I don't know what else it could possibly be? It was bad enough that I was certain I'd broken something quite serious.
