Transmission or T case knocking

[Snii]

It's either the transmission or transfer case that's making a knocking noise, whether in or out of gear, the truck hasn't been...very well maintained in the last 20 years, as my grandfather bought it in 1992? Add to that it's been sitting for a good 5-10 years. I'm just looking for ideas on what to check and what it could be.
3rd gear is out, 2nd gear kicks out if I try to put it in, reverse and 1st go in but the truck doesn't go anywhere. I'm not thinking clutch, since it would go in gear and just not do anything at all. The truck did move when my grandfather got it started the first time, but only about a foot.
It's a 61 Scout 80, 4x4, 152, everything (should be) stock, so t-90 transmission, Dana 18? T case, etc.

 

[Michael Mayben]

The transmission must be rebuilt. Everything described fits right in the pattern.

As for the d18, I'd rebuild it also even though they are extremely strong units. At least for now refresh the oil supply.

The clutch throwout mechanism is most likely shot also, all the Scout 80 clutch systems were a very poor design. We have many threads here in the sub-forums regarding this issue and the fact that the clutch fork will be badly damaged.

Reconditioned parts for the clutch throwout are available right here in the online store.

I'd also replace all four u-joints with new ones, they are all four the same part number. Be certain to keep the sliding yokes in their proper positions when reworking the drivelines.