What year NP231 can I use?

I've got a 2001 XJ with an AW4 and need to swap in a new 231. What years can I use? I've got a good deal on a 231 from a 91 XJ, will it work?

it depends. did it come off a jeep with an ax-15 or an aw4?

you need to verify that it has 23 splines and a medium input length.

http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

The important variations to look for in the 231 transfer case are in the input gear. The 231 comes in 21 spline and 23 spline versions with long, medium (rare) and short variations. The long shafts protrude 2.1" from the front mounting face of the transfer case. The short version protrudes 1.2". The rare medium shaft protrudes 1.7". You should be careful when swapping any of these gears due to different bearing widths and gear teeth. The following chart shows how to determine which input gear you might have by transmission. It is always recommended to verify first hand if possible. Because of differences in the cut of the gear, as a general rule, one should not interchange 1987-1993 gears with 1994-present gears. These years are not always hard and fast delineations. If one is not absolutely certain, dis-assembly and inspection is required. Note that some transmissions change spline count. The Peugeot BA10/5 had both 21 or 23 splines. The AW4 had 21 splines through 1990. In 1991 (the same year the 4.0 HO was introduced) the AW4 splines increased to 23.

*from the internet*

rockclimber said:

it depends. did it come off a jeep with an ax-15 or an aw4?

you need to verify that it has 23 splines and a medium input length.

http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

Click to expand...

It's came off a 91 AW4

then it should be good.