Which years np231 will work in a 1992 xj?

Alright so im quite new to jeeps in general but I've acquired a 1992 Xj automatic in need of a new transfer case (np231). Also I am new to this forum and although I've been on other forums ( used to have a few vws) the search function on this forum is a bit difficult so please forgive me. I'm wondering from which years I can get a transfer case from with little to no modification bolt in would obviously be the best option here for me . Any advice is greatly appreciated. Thank you in advance.

I think you are just new enough to have both the electronic speedo control and a 23 spline input shaft. The input shaft lengths are different for auto and manual, so you just need to find a 92 or later, which you can see from the speedo control, from your transmission type.

Paul

So any year 1992 or after as long as I can see the speedo control. Thanks a lot paul

Novak is of great resources!
http://www.novak-adapt.com/knowledge/transfer-cases/np231/

Not any year. Some time around 96-97 (can't remember) the changed from the internal slip yoke to an external style. This would have to be swapped as well if you went that route.

1991-1993 should be bolt on. Other years (1993-95) will likely require minor modifications, which may or may not be as simple as swapping out the speedometer drive. 1996-2001 will be more effort than they are worth.

The tailshaft difference is plainly visible, so just be sure it looks like yours or take the driveshaft too (or now is a good time for an SYE!). It is the input shaft length differences that are not as immediately obvious when looking at a pic on CL.

Why would a sealed output version not work? I doubt the splines are any different or the shaft is any longer. So physically I see zero reason why it wouldn't work if you get any 231 from a 91+ that came from behind an automatic. May require some basic wiring for the 4wd light in the dash though