No reverse and clunk while driving

[bcranger]

I just bought a 1994 4.0l 4x4 5spd truck with a 1354E t-case and auto hubs. The problem is it intermittintly will not have reverse in 2wd (it grinds) and 4hi it just does nothing but in 4low it backs up fine. All forward gears work all the time. When I drive it down the road in 2wd it occasionally clunks loudly like something is locking up or skipping. if I engage the clutch at road speeds I hear a whirring sound until I come to a stop. I begining to think its the t-case since all the tranny gears work in 4low. Could this be a bad t-case planetary or chain?