xj transfer case swap question - 231's

[shawn]

so the t-case in wifeys 99 xj seems to b fried. she donated her 95 xj to my cause. i have her car at the shop and a plan was to take the t-case from the 95, but the parts guy has a computer program that says it won't work (but won't say why) and that it has to be a '98 or newer.

the 99 is an auto, the 95 is a 5 spd. and both the t-cases are 231's. so can anyone confirm this?

[comanche09]

The yoke setup is different between the two. IIRC 97+ use a sealed tailcone with external splines for the yoke. A boot cover fits over the yoke to prevent debris from contaminating the grease. 96 and below the yoke itself seals the t-case.

 

I am running a '98 NP242 with the sealed tcase output and I had to shorten my driveshaft 1" to run it. Hope that helps.

 

There may be differences in input shaft lengths 5spd vs Auto, but they both should be 23 spline.

[shawn]

yes it does help. thank you. i thought that they looked different, but didnt realize it would not still be a direct bolt-on. thats a shame but guess we will have to have the one in the 99 rebuilt.

[SW86]

so would a 231 from a 95 wrangler with a 2.5 5spd in it be a direct swap? ive got a 4.0 auto or does that matter

[comanche09]

yes it does help. thank you. i thought that they looked different, but didnt realize it would not still be a direct bolt-on. thats a shame but guess we will have to have the one in the 99 rebuilt.

 

Do both XJ's have the same rear axle? (both D35's or 8.25's)

 

If the '99 has an 8.25 and the '95 a D35, you should be able to put the DS and Tcase from the '95 into the '99 and be good to go. Just swap yokes on the driveshafts. Even if not, getting your DS cut down or re-tubed one inch will cost less than if you paid someone to rebuild the '99 tcase.

 

FWIW, my '98 NP242 that was running behind an AW4 bolted right up to my '90 AX-15 that was running a NP231.

 

The other consideration would be that the wiring for the speedo and 4x4 dash light may be different. No too big of a deal and easily fixable.

[shawn]

thats definitely something i wanna look into, especially since i just found out its gonna be a grand -either way. the rebuild or getting a low-miles used one put in.

i do believe the 99 is an 8.25 and a 35 in the 95. the one thing that I'm concerned about now too is the auto / standard issue. - should this be a concern ???

[kastein]

Everything said so far is accurate, except the design changed from 95 to 96, not 96 to 97 - 96 and later transfer cases are the sealed design.

[JeepcoMJ]

I put a non-sealed '93 np231 in a '99 xj, and 25xxx miles later, it is not an issue.

 

 

 

You can put it in. all you need to do is make sure they are both np231's, and clean the slip yoke on your rear driveshaft up to a polish. if your yoke is too corroded to run smooth on a seal, swap in the '95 shaft (so long as they're both auto, or both 5 speed). if worse comes to worse, swap the yokes. even the sensors are direct swap.