Picked This Up Today...

[onlyinajeep726]

I just got back from picking this bad boy up...  It's an AX-15 from a '96 XJ that the seller claims was rebuilt within the last year or so.  No bellhousing unfortunately,  but I did get the crossmember and a few various other parts.  All for $175.  This is the start of my '86 2.5L/AX-4 to 4.0L/AX-15 swap.  I posted this in MJ tech because I need to clarify some things and I'm hoping y'all can help me out.

 

First, I know I need to find a bellhousing, shift fork, external slave and all that stuff.  The thing I'm not sure of is if a NP231 from an '88 or '90 XJ will bolt to this transmission since I'm not sure what each of the spline counts are for an '88, '90 and '96 transfer case.  So, does anyone here know for sure?

 

Also, the rear driveshaft is going to be concerning.  What do I need to know about that?  I should also note that I'm thinking about getting a C8.25 and welding on SUA leaf perches.  Also would like to know what gears would work best with an 4.0L/AX-15 combo.  I know that stock used 3.07s commonly.  I want to make this the most fuel efficient Jeep I can make it.  At this moment, I have no intention of lifting or running larger that 215 tires.  Also, any writeups on the subject are greatly appreciated.  I should also note that I am pulling the engine, computer and all from a '90 XJ with an automatic transmission.  Is that going to cause any issues? 

 

 

 

[onlyinajeep726]

Anyone?

[Pete M]

I'd just leave the 3.55 geared dana 35 in place.  :thumbsup:

[Geonovast]

The older 231s will not bolt up without a new input shaft.  AX-15 needs 23 spline.

 

Your best bet for driveshaft is to have yours cut down.  Keep in mind that going to an 8.25 down the road will result in another driveshaft change.  I think you and I discussed that in a classified thread awhile back.  If you're going to put in an 8.25, best to do it at the same time.

 

I believe the auto computer will be fine as long as the pins for the NSS are jumped.

 

Nice score, BTW.  Sucks you didn't get the external bell with it, but it's rare to see someone grab the crossmember with it.

 

On a side note.  If you end up sucking it up and putting in an internal slave :ack: , make sure you swap the bearing retainer.  And internal slave will not work with the external retainer, and vice versa.