The transfer case on my 1960 f100 4x4 is very loose. I tried just tightening the nuts down a little and ended up stripping out one of the nuts. Anyway, while I'm down there I would like to change the bushings out. The square mounts on the underside seem to be in perfect condition but the round ones on top are very cracked and worn. Where could I get these round bushings? Also do I need to take the t-case off the truck to change them or can I just do one at a time. There seems to be a washer of some sort keeping me from pulling the bushing of the top? Can anyone help me?