Well it looks like i am getting a new transmission...i have a 1990 5 speed cherokee sport and was wondering, since i am on the market for a new tranny should i be looking for something better than oem? I am slowly trying to make this thing my full time rock rig. Is stock oem strong enough to last or is there something better that would work?

 

if it's a 1990 with the 4.0 engine, you have the AX-15 tranny. It is a very good transmission, you're not going to find one better.

Why do you need a new transmission? Never heard of the ax-15 having issues.

Anyways, you can grab one out of any XJ 1990-1999 and it'll bolt right up.

 

If you buy your transmission from eBay or online remanufactured sometimes the company has a towing or plow option which they will use more heavy duty parts. If I ever blow my transfer-case its an extra 100$ for the plow edition off ebay.

 

yea...uh...that's a load of BS don't fall for it

 

I would suggest an ax-15 with an external slave.

 

Really I guess I save myself a 100$

 

That would be the only upgrade worth it. The '94 and newer Cherokees had the external slave or you can get a bellhousing off a newer one and put that on yours. The AX-15 is a fairly bulletproof trans, I'm not sure of any kits that are for extreme duty for them as I haven't seen a need for them. If you have some mechanical knowledge and want to, you can dive in and rebuild the AX-15 if you really wanted to as they are a simple trans to rebuild (I'm assuming you need a syncro or something since you say you need a new trans, they can be had for fairly cheap).

Right now on my Project Comanche, I have a mildly build Chevy 350 (350-400hp) with an AX-15 bolted up to it (Novak adapter plate for a Chevy bellhousing) and I really have no worries. The guy I got the Novak adapter plate and bellhousing from had an AX-15 bolted up to a ZZ350 Chevy 350 (~350hp) and didn't have a single issue with it. He said he managed to crack the housings of NV3550's with the stock 4.0L but has never been able to destroy an AX-15.

 

Kinda off topic here but...

The NP231 is a really easy transfer case to rebuild. For the price of a new one, you can rebuild yours with all new bearings and seals, put in a SYE and a heavy duty chain kit. I've rebuilt quite a few NP231's already and can do a full rebuild now in about an hour. The NP242's are just as easy.

I've abused the hell out of the NP231 in my old Cherokee and only issue I had was that a seal went bad and I got dirt inside the transfer case (reason for the rebuild). As long as the outside seals are good and you don't put off a bad yoke seal (and go wheeling about 10 more times like I did...) then these transfer cases are really stout. I have one of them bolted behind the AX-15 in the Comanche (same one above) and have no worries about it.