t-case noise.

i have a 95 xj with the 231 transfer case. last time on the trails i put it in 4wd and the case started making a loud clunk like the chain is skipping. i wasn't stuck, i had just put in in 4wd to try to pull out my buddies truck and heard the noise before the strap even got tight. put it in the air and when you free wheel it there is no noise, but it you apply pressure to the front tires the case starts clunking. has anybody rebuilt one for this concern. i'm asking because i can't find a used one around here and was wondering if anybody had an idea of what i may get myself into if i tear it apart.

One thing about the NP231 is it is very simple mechanically. You probably either have a chain skipping or it is not fully engaging into 4 low anymore - they wear out eventually and need to be tweaked. Put it in 4 lo, then get under it and see if the linkage is getting all the way into position. This is even easier with a friend - one person putting it in and out of 4 lo, the other under to get more familiar with directionality. After you have determined it is getting all the way into 4 low, see if it is still doing it. Also, have someone from the outside determine if the front tires stop moving during the clunk.

Make sure it is not the linkage before tearing it apart!

the noise happens in both 4lo and 4hi so it is not a linkage issue. we put it on the lift at work and the front tires needed to have press put on them with pry bars to make it happen. and it was definatly coming from the t case. i have read that it is common for the chain to stretch. which i could see with it having 220,000 on it. i guess i am more wondering if i should expect it to be just the chain or if there is a good chance i find something else.

Same thing happened to me today on the trail. 4HI and 4LO. Did you figure out what the problem was? 96 XJ with 231

turned out i had NO fluid in the case, and the chain got hot and stretched. It was rubbing on the bottom of the case. I swapped chains from another xj I have and its all good!