Advice: Xj transfer case from Wrangler

The XJ forums are dead. I need some advice.

96 XJ 2.5 5 speed. Basic little box. Transfer case crapped. It is a 231j, that NV231 21 spline.

I scored a 97 -01 NV231 that looks IDENTICAL in all respects. BUT the input is 23. That we can change.

It's going to a shop on Monday for repairs. Will this 97+ fit into my 96XJ?

Like I said they are identical. Same gear ratio--same mounts, same everything.

thanks I miss my Xj and this is frustrating to find a transfer case to swap in.:confused1

The clocking is a little different, but can be made to work iirc

what do you mean by CLOCKING?

What angle the tcase front output is at, relative to the centerline of the tcase main shaft

Here is what we plan (or will try to install on Monday)...this is a 97-01 MV 231

http://i60.tinypic.com/dxfn9t.jpg

http://i61.tinypic.com/33kgieg.jpg

http://i60.tinypic.com/99g9ar.jpg

http://i58.tinypic.com/dy6uwy.jpg

Now, the Jeep is a 1996 XJ, 2.5 engine, with a 5 speed. The clutch was just done last week. We found the PO did not put the C CLip in on the output bearing shaft, thus it had a huge oil leak. Lord knows how many times this case was run dry,.

Yesterday, it began to jump--slip--the chain is slipping from the cogs. In 4wd, it makes a gawd awful sound--like grinding, (but still drives).

I snagged this transfer case mainly on the numbers that is on the case. They match UP to my XJ.

Other than changing the input from 23 to 21, think it will work????. The case and numbers all match up to my 96 trashed case.

Thanks
Mark in Fresnoatriot:

It will work, just be aware of the potential clocking issues, readjust your tcase linkage afterward, etc

Thanks, makes my weekend a bit less stressful
I love this XJ, but correcting all the mistakes from previous owner's boyfriend's hack job has been a nightmare
:repair:

The clocking difference is in the transmission, not the t case.

I thought 91-92 was the last year for the 231 to have a 21 spline input shaft? If so they should swap perfectly without changing anything

Mnkyboy said:

The clocking difference is in the transmission, not the t case.

Click to expand...

This.

Since both t-cases are 96+, the input SHOULD swap over. Earlier cases had a different cut input gear that won't mesh the same but that shouldn't be an issue.

There are a few funky splits in NP231s.

21 vs 23 spline:
All BA-10/5s iirc had a 21 spline. Not totally sure on this, I avoid those like the plague.
All AX15s had a 23 spline.
AW4s 91+ all had 23 spline.
AW4s 89- iirc had 21 spline, 90 is a maybe-split year I think?
And here's the fun one. All 4cyls that I'm aware of are 21 spline. I know for a fact all 4cyl YJs are 21 spline, I did a transmission on a 94 for a friend of a friend and that's what it had.

tailhousing/slip yoke design:
95 down are the style with the seal riding on the slip yoke, and will leak all your fluid out if you run without a rear driveshaft.
96 up (both your recipient and donor vehicles, so you're fine) are the style with the seal riding on the shaft and a grease boot for the yoke.

YJs use a single cardan/single cardan driveshaft, so YJ NP231s have a different front output yoke that is tapped for ujoint strap bolts just like a d30 pinion.

The split for the planetary gearset tooth profile is 94.0 vs 94.5. Early case parts will interchange with early cases, late case parts will interchange with late cases, trying to mix across that line will result in sadness and glittery oil.

And yes, the clocking is built into the 4WD adapter housing on the transmission, not the transfer case.

Dodge Durango NP231s (all 23 spline, iirc) are damn near the same as Jeep NP231s of the same year, btw. Different front output yoke/flange, rear output shaft, rear output housing, shift bellcrank, and back case half, as I recall, but that's pretty much it. There may be some other internal differences. If you swapped the slip yoke along with the case and slapped an XJ front output yoke and shifter bellcrank on one, you could probably run it in an XJ no problem. No guarantees, but worth a try if you need a case and can't find one in your area, because worst case you can pirate it for 90% of the internals you'd need to replace on an NP231J.

kastein said:

There are a few funky splits in NP231s.

21 vs 23 spline:
All BA-10/5s iirc had a 21 spline. Not totally sure on this, I avoid those like the plague.
All AX15s had a 23 spline.
AW4s 91+ all had 23 spline.
AW4s 89- iirc had 21 spline, 90 is a maybe-split year I think?
And here's the fun one. All 4cyls that I'm aware of are 21 spline. I know for a fact all 4cyl YJs are 21 spline, I did a transmission on a 94 for a friend of a friend and that's what it had.
.

Click to expand...

You missed the 21 spline AX15's in late 89 and 90. And all of the AX5's.

I thought all ax15s were 23 spline. I may be wrong...

And as far as I know all ax5s are 21 spline, which is why 4cyl YJs into the 90s still had 21 spline np231s.

Novak's page agrees, too.

I am honestly unsure what a 4cyl auto would have for a spline count, whether 90- or 91+, as I've never seen one, let alone had a chance to tear it apart.

every AX 15 I've ever seen was 23 spline.
and the one in the 87 was mated to an NP 231 that had a 1990 production tag.

BA 10/5's were 21.