t-case + Drivetrain concerns and help needed

[clapage6]

Hi all, I have a good mechanical background however haven't owned anything bigger than my toyota pickup until a few months back when i got my 83 Crew cab drw for hauling desert toys etc around. Also never did much drivetrain work even though...always been a motor-head while someone else jimmied with suspension/gearing etc...

concerns/advice/pointers needed:

1. Good sized clunk when going into reverse. I've been seeing around could be U-joints/diff etc. Does anyone know of a decent way of diagnosing the exact cause a "SAFE" way?

2. I can hear the tcase gears spinning though the t-case shifter in the cab at all times... gets a little annoying; not crazy loud but i can def. hear it even with my window down .... is this how all np205's are or is there something else wrong? everything seems tight as far as linkage is concerned? Is there a decent thread anywhere with pics on drain/fill/sight plugs on the 205?

I think that's it for now Thanks guys