NP/NV231 rear case halves, differences?

[DirtyComanche]

A friend's father/brother broke the NV231 rear case half in their 02 TJ doing something stupid, I think dropped it on the floor actually, was a maintenance issue rather than a driving related issue.

 

Anyways, I've got a couple 89/90~ NP231s sitting around and I'll tear the case half off one of them if it's the same, but the Crown replacement is listed for 87-96.  I know the slip yoke is different, and the tail housing, but I don't personally believe the actual case half is functionally different.  Anyone know for sure?  I believe it should work and they just bolt their tail housing and other junk onto it.

 

I don't want to tear the tcase apart and find out it's not the same.

[MeanLemons]

Why don’t ya just give him the whole case instead of half? 

 

If his his is a 4 cylinder TJ, then the 21 spline count will match. 

 

If if it’s a 4.0L then he won’t be able to swap over the guts to your half, because of the difference in teeth cut style. 

[DirtyComanche]

Just now, MeanLemons said:

Why don’t ya just give him the whole case instead of half? 

 

If his his is a 4 cylinder TJ, then the 21 spline count will match. 

 

If if it’s a 4.0L then he won’t be able to swap over the guts to your half, because of the difference in teeth cut style. 

 

I have a 21 and a 23 spline input here, he needs a 23.  I don't know, I'm assuming he wants to keep the sealed slip yoke.  And his has a mass damper on it too.   If the stuff will just swap onto my case, I could give him the 23 spline one, but I'm not sure that it will 100% bolt on as I know the shift fork was different.  The other reason I'm hesitant to give him the whole tcase is it's the spare for my daily, the 21 is a spare only for if I need an input.

 

It's annoying, I threw out a bunch of pieces of NP231s a while back.  Absolutely certain there was a case half in there that was good.

[MeanLemons]

All the cases are physically the same. I rebuilt  75 cases so far. It’s the guts that differ.

 

 

[DirtyComanche]

Okay, I'll tear the 21 spline one apart and give him that.  The only thing I want out of the 21 spline one is the input.

 

Actually I might just see if he wants me to do the swap on his.  Not sure how savvy he is.  No idea why they removed the tcase to start with.

[mjeff87]

So they could drop it from a high enough level to break it.......LOL.

 

If you/they just swap rear case halves, there's no messing around with the speed sensor on the TJ case.

[MeanLemons]

Yeah but he still ll have to remove the planetary ring gear somehow and press in his.

 

or unless he find an older style 23 spline input gear and use that 

[DirtyComanche]

39 minutes ago, MeanLemons said:

Yeah but he still ll have to remove the planetary ring gear somehow and press in his.

 

or unless he find an older style 23 spline input gear and use that 

 

No, I'm just going to give him the rear case half.  I'll junk the rest of the NP231 except the input.

[MeanLemons]

What is the year of the t case u are giving him?

 

if it’s pre 94 then he’s gonna have to find an input gear. 

[DirtyComanche]

No.  I'm giving him a rear case half.

[MeanLemons]

Oh.  The cover?  Ok ok. I got the halves reversed lol. 

[DirtyComanche]

If anyone reads this later on down the road, this works fine, as we suspected.