Originally Posted by JVecellio7
New to the forum, joined just for this thread. I would also like to know if this project is moving along. I was just given a 93 wrangler 2.5L ax-5 that has a bad case of frame rot. I just found a reasonably priced 92 frame in good condition that had the 4.0L in it. I have seen across other forums as well that it may not be worth putting swapping from a 2.5 to the 4.0, but if I buy this frame, I would rather not cut/reweld the motor mounts just to put the 2.5L back in.
I have a 98 Grand Cherokee with the 4.0L auto trans and NP242 transfer case. The auto trans is about shot and I was planning on getting rid of the ZJ all together. What are the thoughts on putting the 4.0L from the ZJ into a YJ with the 4.0L frame? Still would need (correct me if I'm wrong about anything):
1. AX-15 transmission from a 4.0 YJ
2. Driveshafts from a 4.0L YJ ??
3. Computer from a 4.0L YJ ??
4. to modify the 2.5L wire harness
5. Anything else?
Sounds like it would work to me. Are you planning on using the 242 though? If so that will cause some issues with the ax15 output shaft and the zj auto input NP242(short vs long). You should be able to find a np231 that was mated to an ax15 for about $150 and pawn yours off for the same, or check ebay for the 23 spline long input shaft and take the 2.5l one apart.
Also, the wire harness will swap over with lengthening of a few wires, and you can use an xj or yj computer with manual tranny the same. from 91-95
I want to say your stock driveshafts from the 2.5l are the same length as the 4.0l since the ax15 and ax5 are the same length with the transfer case. (could be wrong so hopefully someone will confirm)