What years did the transfer cases change splines and tranny swap question.

I have a running motor with less than 100k on it out of a year 2000 XJ (in fact i have the whole wrecked XJ) and want to swap the motor it into my 87.

The 2000 model is a 2wd so thanks to the info from this board i know its not really practical to use it due to the output/tail shaft. With that in mind i am going to need to get a new transmission and 231 transfer case.

As i plan on using the harness and computers from the 2000, so what years transmissions will be "bolt in and plug and play"? i have found one for sale that says its for 99-2000-2001, will that bolt in and plug into the harness from the 2wd without any really issues?

Also this 99-2001 transmission will have a 23 spline output shaft right? What year did they change over to the 23 spline output shaft (from 21) and i am guessing that any 231j after that year should fit correct?

I am having to buy this in bits and parts as i just dont have the funds to buy that tranny and the t-case at the same time.

Is there anything else i should be thinking of or planning on before i do this swap?

Thanks as always in advance for the help, you guys here on :: keep my XJ on the road and trails!

Thanks!
Dave

Ps Happy New Year!

I have the same question about TC spline count on the NP231. Anybody have the answer? Is a 1994 NP231 23-spline output shaft the same as a 1999?

Which output shaft? I believe the transmission output shaft is the only one that changed at all, 21 spline till partway through 90 and 23 spline after that. AFAIK the transfer case output shafts have remained the same the whole time - rear 27 spline, I think the front is 32 spline but can't find a page to verify this with.

EDIT: as for length of the rear output shaft - not sure. Sorry.

This applies to XJ's but some other models are similair.

91-01 4.0L use 23 spline inputs, 87-90 4.0L use 21 spline.

Input gears are swappable between 87-94 years or 96-01 years but not with each other.

There are I think two different lengths on auto vs. manual trans.

The mainshaft bearing in the input gear is pressed to a different depth on 231 vs. 242 which can be changed with a press or puller.

The mid 98-01 AW4 has two speed sensors vs the 87-mid 98 which have only an output sensor.

To work with what you have for sure yes a 99-01 trans is what you need.

If the '00 was an auto you 'll have to use an AW-4. If it was a standard, you either have to use a standard, or piggy-back an early TCU.
Transferring the wiring over to the '87 is going to be a heck of a project. Count on swapping the gas tank, fuel/vapor lines, and maybe the steering column.
You're basically building an OBD-2 system.
What might be easier would be converting the '00 to the 87 electronics, keeping the '00 intake & TB, converting to distributor ignition, then installing the transmission of your choice.
Was the '87 a 4.0 to begin with? Was it 4wd?

As far as what bolts to what, this might help:
http://www.naxja.org/forum/showthread.php?t=101238
http://www.naxja.org/forum/showthread.php?t=101120