Green & Yellow

Found this on craigslist today and immediately called on it. Owner claims it is an AX15 with only 36,000 miles on it (was out of an XJ from the cash for clunkers deal). Everything feels tight on it when I turn it over by hand, it is fairly clean as well. The output shaft has 23 splines if that matters. So was $220 a good price for it and is it really an AX15?

Now the next question:
I have an 88' MJ with a 2wd 5 speed in it (tranny unknown at this point), will I be able to replace that with the AX15 so I can convert it to 4wd? Or is it a bust and I will just have to get rid of it and find an AX5 that is 4wd? Thanks again guys, I used the search bar but didn't quite find the answer.

Parsnip

To be sure its an ax15 you'd probably have to look at the tag on the tranny. But you do have an ax15 in the Comanche. AFAIK the only transmissions used in the late 80s to 90s were aw4 auto or ax15 manuals. 220 bucks is a hell of a deal for a tranny...id be a little suspect tbh. Output doesn't really matter until you want to put a tease in it, then you'll have to make sure the TC accepts 23 splines

Green & Yellow

Thanks! Where would the tag be located? I have looked all over it and only found those two numbers (in pictures above). I also just picked up an NP242 transfer case with a 23 spline input shaft as well as a Dana 30 and a front driveshaft for $175. Looks like i have almost all of the parts for the big swap but not quite, still need the shift linkage for the TC as well as a rear drive shaft and some minor things...

99 Purple XJ

Yes that's an ax15 its an external slave cylinder 4 wd later model and yes it will fit your mj

5-90

The early 88MJ will have the BA-10, the late 88 MJ will have the AX-15.

To tell them apart, you can slide under and look at the transmission case - if you see it split longwise across the bottom, it's the BA-10/5. If it looks like the one in the pix, it's the AX-15.

The BA-10 has a 21-spline output, the AX-15 has 23. The earlier AX-15 (through ~1993, with the "internal" slave - AX-15i) may use the same clutch kit and hydraulics as the BA-10. The later AX-15 (1994-up, with the "external" slave - AX-15e) will also swap in, but you'll have to change the hydraulics. The clutch friction is the same (you may also have to swap the pilot bushing - depends on the size of the AX-15 pilot. The BA-10 uses a ~5/8" pilot, the later AX-15 uses a ~7/8". If you have the larger pilot, you may use a pilot bushing from an early 1970's CJ with the V8-304 and three-speed transmission.)

Both the AX-15i and AX-15e will swap into the place of the BA-10. You will need to either change the transfer case input gear or the entire transfer case - but the length on the AX-15/NP231 is essentially the same as the BA-10/NP231, so the same driveshafts may be used. The same crossmember may be used, there is an extra set of holes in the "framerails" to accommodate it (I believe the mount moves back, so the crossmember moves back. But, I didn't have to drill any holes.)

The shift tower on the AX-15 is a few inches behind the BA-10, so you'll have to cut the transmission tunnel opening a bit to accommodate that. I think I relieved it about 3".

If it's the XJ version (as you said,) it will have the proper clocking on the tcase adapter to also fit your MJ. The YJ/TJ version was "clocked flatter" (to improve undercar clearance,) and it would require either changing the tcase adapter housing for the XJ/MJ/ZJ version, or redrilling the mounting stud pattern in the housing, or doing some sheetmetal work to clear the transfer case body being higher. Doable - but irritating to most.

With the external slave, you'll need to buy hydraulics as well - same clutch friction will work, but the throwout bearing will be different (you can just get the later kit, so that's no trouble.) However, the external slave cylinder volume differs from the internal, and the fluid connections differ, so it's easier to just get the master cylinder, slave cylinder, and line. The same pedal & linkage are used.

Green & Yellow

Wow, thanks! So here is some of the info I have collected from my purchases:
I have an AX15i (seller claims it was from a 4.0 93' XJ which supposedly had only 36,000 miles on it). It has a 23 spline output shaft, the input shaft I am unsure of at the moment, I may use my caliper to see exactly what it is.

I also have an NP242J transfer case, mileage unknown at this point however it has the 23 spline input so I assume it will hook up to the AX15. (if not it is a great spare for my XJ which has the AW4 and NP242J).

As far as other components I have a Dana 30 (seller is gonna deliver it to me as it wouldn't fit in my XJ yesterday). Feeling kinda stupid for not really looking to see if it was a high pinion or not, I guess we'll see. I also have the front driveshaft off an XJ. So from the sounds of it I will need all of the shift linkage for the transfer case (sounds like a trip to pick n pull to me) and possibly a rear driveshaft (can I cut the 2wd drive shaft to length?). I also am eying a Ford 8.8 on craigslist but burnt up my funds yesterday, if it is still available in a week or two I may run out and check it out. I really appreciate the help guys! So far my parts total is $395 for the AX15, NP242J, Dana 30, and front driveshaft.

Green & Yellow

Just found this: https://www.cherokeeforum.com/f10/si...inkage-163872/

I may go with their simple linkage kit for my transfer case, it looks way better than the stock linkage. Opinions?

http://froehlichsuspension.3dcartsto...ment_p_24.html

5-90

The "input shaft" (the splined part applies here) is 1.125"-10 all the way up. The pilot (the smaller bit at the extreme end) is the bit that varies. It is also important that the pilot bushing fit properly - a shaft must be supported in two places to run true, and the pilot bushing is the second point of support for the input shaft. Failure to support it will wreck the input bearings in short order.)

I want to do a similar mod - my dream would be an NV3550 or NSG370 with a D300 behind it, but an AX-15 or NV3550 with NP242 would be acceptable (the FT4WD option would be handy in foul Wx - since there fewer competent drivers in CA than I have digits on my hands & feet, and I want every advantage I can get!)

Or just get a linkage kit from Novak, which is easier to adjust. I think it can come with the internal handle as an option - are you doing a 4WD retrofit?

A driveshaft can be shortened, but a certain amount of precision is required. The Cardan joints (shaft at rest) must be in parallel planes, and must be on the same axes - one should "fully eclipse" the other (failure to line the joints up properly - to "phase" them - will get you more vibes than you want. It's doable, and it's even doable at home, but you're best at least having the shaft balanced when your done. Or just having a driveshaft shop do the job for you - they've got jigs to ensure joint phasing.)

Green & Yellow

I crawled under the MJ today to see what tranny I have. Looks like an AX15 to me, and it is an AX15i. Looking at my current setup it has the mechanical speedo cable whereas the NP242 has an electric hook up. Can I just remove the electric speedo from the NP242 and replace it with my mechanical speedo cable?

I also measured the very end of the input shaft on my 4x4 AX15. It measured out to 5/8" with the caliper, I have a feeling it is almost exactly the same as my current AX15 set up and that I may be able to just swap most all of the parts over in the conversion (internal slave cylinder, clutch, etc).

On another note I still needed some more parts (shift handle for inside cab for transfer case, I have decided on getting the simple linkage in which I posted a link of earlier). So off to Pick-n-pull I went. This was my first time at pick-n-pull, so needless to say I spent several hours there looking through every XJ as well as the one MJ that was there (poor MJ only has 76K miles on it). I can admit I am not a fan of my current gauge cluster on my MJ, the massive fuel gauge is just too out of place, a Tachometer needs to be there. So I got one, then another (got a backup for my XJ ). I adjusted my new gauge cluster so it reads the same miles as what are currently on my MJ, I did check into Oregon laws to be sure it was okay for me to do so (I want it to read the same anyways). I also got multiple other miscellaneous parts while I was there. So now I am thinking about doing the gauge swap tomorrow, eventually I will do the 4wd conversion but I still need to order that linkage and get the backlight & wiring for my 4wd shift indicator. Thanks again!

5-90

Don't forget that the oil pressure sensor and the coolant temperature sensor at the driver's side rear of the head will also want replacing - but those are easy to access. However, be careful with the temperature sensor - it's easy to break that one!

When you put the new sensor in, you should use PTFE paste or Never-Seez on the threads - coat the threads, tighten with finger pressure only, and then tighten 1-2 flats past finger tight (1/6 to 1/3-turn) with a wrench (when using applied torque to measure preload or sealing, you must reduce torque with applied lubricants. When using a "torque angle" method, applied torque becomes irrelevant, since 60* is 60* - lubricated or no.)

But, the rest of the swap is easy - I've done it a few times.

Green & Yellow

Well I got the gauge cluster swapped. Hardest part was the speedo cable, had to crawl under the MJ and take it loose from the tranny (destroyed the O-ring while removing it) and also pulling the little support clip up by where the exhaust bends (kinda near the O2 sensor). First time I did it i decided I didn't like the battery voltage gauge (8-13-18) instead of the common (9-14-19) gauge. So out it came and I swapped it. The oil pressure gauge also didn't read right, so I swapped that as well. My MJ already had those gauges, the only gauge it didn't have was the tachometer so no switching sensors required . Got it all put back in and the fuel gauge didn't work (ended up where the plug in the back wasn't tight enough) so out it came again, off came the speedo cable again. Then in the process I locked my keys in the MJ so I had to get in the XJ and drive 20 miles for my spare keys. (at least I have a spare for my XJ on me at all times). Finally got the gauge cluster back in the MJ and buttoned it all up. Everything seems to work, want to get some gas to see if the gas gauge works and may pull it back out since the blue lights I put in the gauge cluster are too dim (shoulda got LED's. ) Oh well, atleast my Tach works, now I gotta look into my low idle issue (500 RPM's, let off the gas from about 2100-2200 and it drops to 500 but doesn't die). I may check my grounds first, from what I've read from one of the members on here about the renix era Jeeps I think that would be a good place to start. Or it also could be linked to my battery which is 8 years old (will be replacing soon), but then again it shouldn't since the alternator is cranking out plenty of juice (right about 15 when I run it). Not a huge problem right now as it is my project, not my daily driver. As of now it probably wont be my daily driver until it is at least 4wd.

Green & Yellow

Well, I started to think about the swap and now I gotta figure out how I am gonna wire in the TC. While at Pick-n-pull I forgot to grab the wiring harness for the NP242, where exactly will it hook to my MJ? What is the purpose of the wiring harness besides turning on a light in the dash when you engage it in partial or full time 4wd? On another note I also need the wiring that goes to the light below the TC shift indicator, I also forgot that at Pick-n-pull. The Dana 30 I bought off craigslist also has not been delivered by the seller, my plans were to go through it to make sure it is solid and in good mechanical condition before I install it on the MJ. What really makes it hard is something in the back of my head just keeps saying regear the axles while they are out, put bigger tires on it, and throw a lift kit under it. But then I come back to wanting to lift the XJ first. Either way I have to buy new tires as the ones on my MJ are junk (and way too small). So I guess I will have to make a decision sooner or later. Lift the XJ and throw those tires on the MJ or lift the MJ and throw new tires and rims on it.

salad

The threaded hole at the front of the NP231 and NP242 cases is made to accept either the vacuum switch or a plain electric switch. In the electric setup the switch will illuminate the part time for full time 4WD lights on the dash - no hidden magic. In the vacuum setups, it passes vacuum through to the front axle disconnect motor, which, when engaged, will pass vacuum up to a sensor that I THINK is located on the firewall. This final vacuum sensor is what illuminates the 4WD light on the dash.

Hopefully a Renix person will be able to provide you with some words on harnesses or diagrams. At any rate it really doesn't do anything except illuminate a bulb

Green & Yellow

Okay, thanks! I will have to do some research on that I guess.

Green & Yellow

My Dana 30 finally showed up! It was covered in mud (the XJ it came out of was wheeled before it was parted out). Last night i got out the pressure washer and degreaser and gave it a good cleaning, so far it looks like I will be rebuilding it before it is put to use. It seems to have a little slop in it so you'd say:
I also seem to be missing a plug for the pumpkin, I turned it over and some oil came out. Oil looks pretty decent, more clean than dirty. You can also see how it was removed from the XJ, if the bolt wouldn't come out than the part was cut off. Overall I am satisfied, now I just gotta decide if I want to regear it when I do the rebuild, if so it could end up in the XJ since I foresee a 4.5" lift in it's future.