88GTBlack

from what i understand there are internal slave ax15 and external also there is a np231 like i have, but i see np231J np231HD what one do I need I need to do a complete junkyard swap brackets and all will other ax15s fit from dodge dakotas toyotas and what not?

88GTBlack

ahh mann bump!

PingPong

I did this swap a yr ago.
1. you wil need clutch master cylinder, and slave cylinder, and the hose
2. you wil need an AX15 crossmember
3. you will need the body side of the t-case shifter linkage as well as the rod from the bel crank to the t-case
4. you will need a 23 spline input on your t-case
5 a complete ax15 including bell housing

88GTBlack

i know this is going to sound crazy buy i found an 84 jeep with an ax15 which ones can i use and which ones cant i from which model years?? if i do the swap it will be junkyard

5-90

OK...

Feels like I go over this about once a month or so - so bear with me if I get a bit short (but I do get tired of answering the same questions time and again...)

1) Read this thread - http://www.naxja.org/forum/showthread.php?t=70388. All of it. Then read it again. (I know I've posted this link several times before. Yes, I've contributed to the thread as well, detailing what I've found in my own swap.) The thread is directed toward the XJ community, but the YJ conversion also finds it useful (the difference between the XJ and YJ, as far as this goes, is that the YJ has the transfer case clocked "flatter" than the XJ and MJ - and even the earliest ZJ.)

2) Read that thread one more time. It will help you, and it will answer most (if not all) of your questions.

Now, let me hit some of the oddball stuff that you're asking...

The AX-15 was used in several vehicles - it's a Toyota box, actually. Therefore, it can be found in some Toyota pickups, the 1988.5-up XJ w/6-242, 1988.5-up MJ w/6-242, 1993-1994.5 ZJ w/6-242, and the Dakota with 4-150 and V6-239 (the 4-150 is, in fact, the same AMC engine that shows up in the XJ, MJ, YJ, and TJ, before production halted at the end of the 2002 model year and it was replaced by the 4-148.)

HOWEVER, you'll need to find your bellhousing from behind the 6-242, for it to swap. The V6-239 uses the Chrysler LA-block bellhousing pattern, and the 4-150 has about even odds of being either the AMC I6/V8 or GM Metric bellhousing pattern. The 6-242 uses the AMC I6/V8 bellhousing, in all cases.

Also, if you source your AX-15 from a YJ or TJ (to go into the XJ/MJ/ZJ,) you'll need to clearance the transmission tunnel for the transfer case. If you get it from Dakota/ZJ/XJ/MJ to go into a YJ/TJ, you'll lose some ground clearance and breakover angle, until you re-clock (drill the adapter, or install a clocking plate, or get a proper adapter.)

It should be further noted that there are two versions of the AX-15 - I call them the "AX-15i" (internal slave) and "AX-15e" (external slave.) The two are mechanically compatible, but use different hydraulics. They break for the 1993/1994 model years (up through 1993, they're the AX-15i. 1994-up will be the AX-15e.) Both versions have different pilot diameters as well - the AX-15i uses the same size pilot as the BA-10/5, the AX-15e is larger (requiring an "off-list" bushing.)

The AX-15i may be converted to the AX-15e (and vice versa,) by swapping the following parts:
- Bellhousing, including associated clutch parts (fork and pivot)
- Slave cylinder
- Throwout bearing
- Front bearing retainer (this one is critical! If you don't put the proper retainer under the AX-15e T/O bearing, it ain't gonna work. Period. End of discussion.

The reverse is also true. I do not know (yet) if the input shafts will swap - it's on my list to find out as part of a refit on my 88 (going to an AX-15e, from an AX-15i installed in place of a BA-10/5.

The NP231 is, of course, the transfer case. There are different versions of the NP231 out there, and they differ primarily in chain width. The NP231J is actually one of the weaker versions, with the NP231C (Chevvy) and NP231D (Dodge) being superior. There is also the NP231HD (Heavy Duty, used in some full-size Dodge 1/2- and 3/4-ton pickup) and NP231DHD (Dodge Heavy Duty, used in 3/4-ton and some 1-ton pickups.) Make sure they've got 23-spline input gears, and they'll fit neatly behind the AX-15 (but make sure, with any swap, that you note the donor vehicle for parts information. Technical specifications may be the same, but I'll just about guaran-damn-tee you that internal parts will be different! Once you start swapping things about, you'd better keep a permanently bound notebook detailing parts, donors, changed specifications, and the like. Keep it next to your shop manual.) There is some small chance you'll have to adapt, or fabricate new, the transfer case linkage after a swap, and you're likely to have to do so to fit the AX-15 in place of the BA-10 and have functional 4WD anyhow. Leave it to creativity, or purchase a kit from Novak (which I intend to do - as I recall, their kit will also work when putting an NP242 in behind an AX-15. Unless I get really lucky, and can nail down a D300 and/or an NV3550...)

NB: The NV3550 showed up in XJ/TJ and Dakota around 1999 (2000 for XJ,) and some small Chevvy trucks as well. It accepts the same bellhousing as the AX-15e, which simplifies finding a working conversion (the inputs are all, as I recall, 1.125"-10 splined, and I think the pilot is the same size as the AX-15e.)

Now, did we miss anything? Do have some patience tho - if you haven't gotten an answer yet, it could be because the guy who has it hasn't checked yet (for instance, I only go through Jeep boards once or twice a day to check for new threads in between everything else...) and he'll be along soon enough. Clicking "New Threads" will give you everything that's changed since you last logged in ("you", in this case, used generically...) and "Bumping" a thread is bad netiquette - particularly if you do it inside of 72 hours! This goes all the way back to Usenet (instant gratification, while increasingly popular, isn't always workable. "What is Popular is not always Right, what is Right is not always Popular.")

88GTBlack

you are indeed the man. you belong in one of those budweiser commercials real man of genious. Today we salute you Mr. 5-90 parts information guy!

5-90

It's more a matter of focussed research than anything else - and I was just organising information on transmissions and transfer cases anyhow. You should see my notes...

awilson42

Thank you for the great information.

I recently ran into issues with my Clutch Hydraulics, and want to "upgrade" from the 1993 internal to the 1994 External.

Sounds like I just need to hit the junkyard for the Bellhousing, Fork, and pivot, and then purchase new Throwout bearing, front bearing retainer, slave Cylinder, and clutch hydraulic line for 1994 (The Master cylinder seems to be the same). It seems like a good way to go for long term - the parts for 1994 and up are cheaper and more common than the 1993/older. And I REALLY would prefer the slave Cylinder to be on the outside.

If you have any corrections to this, or additional info, please do share. This is a project slated for this summer (will also likely upgrade Transfer case from existing 231 to 242).

Robertb

OK so I’m doing a BA-10 swap to an ax15 the BA 10 was 1988, the X 15 I’m putting in is 1989. I am using a centerforce II Clutch. I am blowing out slave cylinders they are to short. it is an internal slave cylinder I can’t even get them bled is there a reason why or is there a fix for this that you can think of like a shim or something