SORRY everyone....my bad !!! It is NOT a 87 ...it is a 91 cherokee....

Need help here....asap !! thanx in advamce....have a 95 cherokee auto....and a 91 cherokee 5 spd...both have 231 J tcases....the 91 has a 2 wire plug (vac I assume) and the 95 has a 3 wire....Do I just have to swap the plugs....both are open cooling sys....so they should both be 23 spline right ???? Need all the advice/expertise I can get.....new to the jeep world....will the tcase out of the 87 fit in the 95 without major work ????? I am in a bind here and pressed for time !!

 

If you have a 1987 XJ, that would have an NP207, I believe. The NP231 was introduced in 1988. However, let's assume that you somehow have an NP231 in your 87 XJ. The 231 out of your auto mounts up slightly different than the one behind your 5 speed, as the shafts are longer on the ax15 than they are on the aw4. As far as the plug goes, in 1992 (IIRC), Jeep introduced a different electronic vehicle speed sensor. That's what that is. Prior to that, they used a mechanical cable driven speed sensor.

In a nutshell, here's how transfer case interchangeability breaks down:

Behind an ax4: short shaft input, 21 spline
Behind an ax5: short shaft input, 21 spline
Behind an aw4 (1990 and prior): short shaft input, 21 spline
Behind an aw4 (1991 and after): medium shaft imput, 23 spline
Behind an ax15 (1994 and prior): short shaft input, 23 spline
Behind an ax15 (1995 and after): long shaft input, 23 spline

That covers the vast majority of transmission and np231 combinations that were natively found in XJs.

Best of luck, man.

 

Cant bolt on a 80's tcase to a 95 transmission. Different spline count on the input. You want a tcase from 92-01 for your 95

And yes the AX15 is shorter than the AW4 so the driveshafts are different lengths, but can be overcome by finding an auto XJ with a d35 and using it in a AX15 XJ with a 8.25. Thats what i did with my 4x4 conversion

Edit: You can take the internals of the 88 case and put it in the 95 if thats the problem

 

Hmmmm....the 87 xj does have a 231 J in it....still has the tag on it. on the 95 auto, high range is gone , only have low range, I think the chain broke on the high range....and its clunking etc in low range now. might end up swapping guts