I recently bought a 91 Cherokee and the trans went out in my drive way it was an AW4 trans I bought a used trans from an 87 xj that I later discovered uses a 21 spline tcase and mine was a 23 spline can I use any old xj 21 spline tcase or do I need a specific model number and can any one decide the tcase manufacturer tag.

 

The 21-spine NP231 transfer case was used from 1988->1990. A 1987 would have had either a NP242 or NP207
https://www.naxja.org/forum/showthread.php?t=1053970
https://www.motortrend.com/how-to/15...ransfer-cases/

Curious, what "went out" on the old transmission?

 

Well I went to the store and on my way home it started slipping the when I got into to my drive way I had no gear at all the next day I went out and got two blocks from home and it started doing the same thing so I limped it home u was told by a couple trans shops it was the pump in the trans but my boss suggested the torque converter went bad it was just easier for me to get a new trans for the moment while I rebuild the original

 

I am also curious it maters if the used transfer case came off of a manual transmission or not

 

Should not matter.
https://www.novak-adapt.com/knowledg...vg-input-gears

 

87 optioned with a 231j small spline, I've had several of them. I believe the 207 was 86 and older - I believe that because I have one in my 86xj currently.

91+ and the big spline -23 literally grab any 231j from any xj 91 and newer, preferably one from a 96 and newer xj because they have a sealed output. Meaning you remove the rear driveshaft and it doesn't leak out fluid vs the older style that seals on the slip shaft of the driveshaft

 

Have you ever adjusted your throttle valve cable? What's the fluid condition? Level?