So I have a 2001 XJ with an np231 case that just crapped out. The jeep still drives but the case grinds very badly under moderate throttle input. When the case is in neutral I can hear something rattling around in there. I'm looking at transfer case rebuild kits and I just don't know enough to pick them out. It looks like some of them come with just bearings, while others come with chains. I'm guessing that if I broke the chain I wouldn't be going much of anywhere at all and that this is probably a bearing issue, so I would be fine with a rebuild kit that just replaces all the bearings? I suppose I could just get out there and start tearing it apart but I wanted to get some input first since I'm a newbie to transfer cases.

 

I am curious as well.

 

I would pull the transfer case out first and check it out before you buy anything. Then you will know exactly what ur looking for. If your unfamiliar with transfer cases, they are pretty simple and you can figure it out easily with a little research

 

What 93 said.
Plus with a rebuild you will be replacing the chain.
Contact xjwonders. He rebuilds them.