also, common one in my experience...bad cross shaft front bearing. that would give you no issues in 4th gear, and only a few in 3rd.

...I've blown up enough ax5's that I used to combine them to make good ones. they last me about 1,000 miles behind the buick 3800 series II that I put in my 86 comanche.

 

So, we've been really considering the AX-15 to swap in (if we can find one). I found a page at Advance Adapters for a kit to swap the AX-5 for the 15....but it's all for Wrangler's. Would a Wrangler kit work on a Cherokee?

Advance Adapters AX-15 Retrofit Kit