With the axle welded and assembled, and the truck kind of lifted, we moved onto the transfer case. I did a little research as to why it wouldn't go into gear, and quickly surmised that it was all in the shifter mechanism. It turns out that the shifter sits on a little bushing known as a shifter sheet, and over time it wears out. A stock replacement is cheap, but we chose a polyurethane version from Petroworks that should outlast both the truck and us. This piece can be swapped in without removing the transfer case by working down through the hole in the floor of the truck, but I had other plans.