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Discussion Starter · #1 ·
I have an 87 yj 4.2 L with the BA10/5 tranny and np 231 T-case. One day I was accelerating from a stop when the rear driveshaft broke lose and started violently thrashing. I immediately pulled over, and looked underneath to find it was bleeding t-case fluid everywhere. After closer inspection I found that the rear U-joint somehow fell apart, and the torque of the flailing driveshaft cracked the t case.
Anyway now I'm working on getting a new T-case, and am having a difficult time. If I could find a good deal on a newer AX15 with 231, I might take that opportunity. The problem I see with that is that all the AX15 with 231s I'm finding at the junkyard have electronic speedos. Does anyone know how I could make a conversion between a mechanical speedo and the new ones? If I do end up just getting a tcase, does anyone know the years that would be directly compatible with the BA 10/5? There are plenty of cherokees at the junkyard but I'm just not sure of compatibility. Any answers or advice would be much appreciated.
 

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the speedometer adapter from your transfer case will swap over to the new electronic ones. Its a 1 bolt and clamp to remove it and then just needs to be clocked correctly in the new transfer
 

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Discussion Starter · #3 ·
So that would allow me to go newer with a transfer case, accept with the input shaft problem, I believe the BA10/5 has a 19 spline, whereas the AX15 has 21 spline. Any idea on that conversion? Also how would I clock the new transfer case?
Thanks a lot!
 

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find one from a 4 cyl, it will work.
 

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The BA10 has a 21 spline and the AX15 has 23 spline. If you are getting an AX15 with transfer case then you don't need to do anything for input shaft. But if you only get the NP231 then to mate it up with that BA10 you'll need to convert it from 23 to 21 spline.

If you upgrade to the AX15 make sure you get the external clutch slave cylinder. You'll also want the bell housing.

For the Speedo cable, just remove the housing and put this in your new NP231 case. You might have to swap speedo gears as the one you have is a long shaft and the newer NP231 may use a short shaft.
 

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Discussion Starter · #7 ·
It looks like swapping between speedos won't be that difficult, thanks guys! Ourlee I might have to take you up on that offer but first I would like to look into if I could swap an AX15/NP231 from a cherokee. I heard that the transfer case clocking was different, but other than that and the external clutch slave cylinder what else might I find that would set me back in doing this conversion? Again thanks a lot guys.
 

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All the time. Very common.

Max
 

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i also have a 5 sp trans. from the same truck, also in perfect shape. pm if you want phone pics.

good luck. rick
if this trans is from the 4cyl yj that you mentioned earlier, it's not an AX-15 (unless it was swapped in) like the OP is looking for, it's an AX-5, that's not any stronger than what he already has
 
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