1987 XJ tranny/x-case swap question

[nyfallen]

I have a 1987 XJ with automatic transmission...the trasfer case is shot....wondering if an automatic tranny & transfer case NP242 out of a 1994 XJ sport would swap and what other things might have to be done to make it work...or is it simply drop the old tranny n tranfer case and bolt up the new one and go?

[nyfallen]

sorry forgot...my 87 XJ is a 4.0 4x4

[Menzenski]

The output shaft on your 87 AW4 tranny is 21 spline, and the output of the 94 AW4 is 23 spline, which means that you'll need to swap transfer cases too. Since you said that you're doing that, you should be good to go. Did your 87 have an NP242 as well, or a 231?

[non-stick]

You may run into computer issues. I believe that the '91 and up trans uses a different TCU that the '87 did. If it's just the tcase that's shot have you looked at a replacement or rebuilding? Repalcing/rebuilding the tcase may be simpler in the long run if you have to adapt a bunch of wiring and electronics to make the trans work right.

HTH

[nyfallen]

thanks for the replies guys...it's a NP231 t-case so just going to get another one instead of going thru dropping the tranny....putting the other in and doing mods to the shifter and possibly needing a different drive shaft...so off to the bank I go

[lawsoncl]

You may run into computer issues. I believe that the '91 and up trans uses a different TCU that the '87 did. If it's just the tcase that's shot have you looked at a replacement or rebuilding? Repalcing/rebuilding the tcase may be simpler in the long run if you have to adapt a bunch of wiring and electronics to make the trans work right.

HTH

94 and 87 tranny are the same. The 87 TCU will work just fine with it. 96/97 is when the tranny had some changes that will cause problems trying to swap.

[BrettM]

94 and 87 tranny are the same. The 87 TCU will work just fine with it. 96/97 is when the tranny had some changes that will cause problems trying to swap.
differences:
-spline output (21 on the old, 23 on the new)
-OD ratio (.705 on the old, .75 on the new)

everything else is the same including wiring harness and TCU compatability.

[lawsoncl]

Thanks. Guess I should have clarified that I meant electrically.