Only way is to take the cover off the transfer case and have a look. If your ok with the tools it can be done in a day. The time consuming bit is taking the Torsion bars out, rear suspension member, disconnecting the fuel line
Tools yeah I've had hold on pliers .
Point is there could be ordinary bearings which you go and buy, or it could be specific which you have to order and wait two weeks or so.
I'd like to to the job with parts ready.