You might look into why its not engaging. It could be a linkage problem or it might not even be your transfer case. Have you checked to make sure your front axle locked in? Jack it up and put it in 4 wheel drive, See if you can turn the front drive line without moving that back. If not your problem is in your front axle. If the drive line does spin freely, It could be the chain in the transfer case which is an easy fix.
1992 Jeep YJ 4.0/AW4/ATLAS
60's on 40s