Hoss - buddy of mine had a YJ a year or two before they switched to TJ. It had an AX-15. He had a lot of problems with that one. I dunno if they switched later on.
The guys over at www.pirate4x4.com (http://www.pirate4x4.com) with be familiar with your ride. They occasionally get on flame fests over there so you oughta feel at home.
BTW - TC = transfer case