Are you sure its the transfer case? The transfer case is hard to break but the front axle & CVs are more problematic.

You should be able to source a new transfer case from another TOD equiped Isuzu with the same auto tranny. You may get a different low range as many models came with a 2:1 low range rather than the 2.48:1 ratio we have in the VX... or you could upgrade to a 3:1 transfer case from Indy4x which would be a nice upgrade for trails (if you're into that). A new transfer case should be pretty easy to install with a tranny jack & some sockets. Sorry no links to new transfers cases... thats your job .