Np-242 t-case question

I've been curious to know if the 242 tranfer case is the same exact unit from 87 on to 01? Have they made any changes in them since they started putting them in the XJ's?The reason I ask is I just got an 88 Limited XJ and it has the 242 in it and my 01 XJ has the 231. I would really like to put a 242 in my 01 and I was thinking about swapping them out. Would it be a direct swap? I would probably need to have it rebuilt, i don't know, but i kindof worry about an old unit like that. any help would be appreciated, thanks

In 91 the input gear changed from 21 to 23 spline, other than that they are interchangeable.http://www.hobbyguild.com/jeep/index.html
http://www.weatherlover1.com/jeep/242.htm

Thanks that helps alot. Another thing though, I wanted to put a nv3550 manual in my 01 also with the 242. Would there be any problem with that?? On the Weatherlover1.com link the guy said there would be more gear slop with it behind a manual. I didn't really understand that. Could anyone explain that to me?? Thanks in advance.

I briefly (read one week) ran a 242 behind my AX-15 and 4.6L stroker... It is difficult to describe, but it "feels funny", unpredictable torque transfer to the rear wheels, jerky driving... I wouldn't recommend it. The full time option in the 242 seems designed to work with the softer torque applications of an automatic. Also, IIRC, the 242 has a lesser torque rating than the 231, and with a manual all the torque goes directly to the tranny, without the buffer of a torque converter...

Thanks xj-grin. So did you switch back to a 231 after that week?? If so, was there a big difference between the 231 and the 242?? I really want to put a manual in my 01. I would chose a manual over an auto anyday. especially when bad sensors causes mine to not shift right.

I have always been a manual fan, and yes, I am currently running the AX-15/231 combo. It is still a little jerkyer/torqueier (?) than alot of people would like, but that is primarily the result of 300 lb./ft. from the stroker

I would stay away from the manual 242 combo, you'll just have to choose which you want more...

Thanks. I think I'll take the manual route with the 231. Thats less work anyways. lol