ZJ AX-15 Swap

[AKMark]

Some have commented on my signature as I have listed that I'm in the middle of an AX-15 swap in my ZJ. I figured I'd start a Tech thread so that in case those with ZJ's would like to persue this, you can.

A similar post is on Jeepforum.com where I'm a regular.

I did this because I've had several Jeeps. My wife had a 99 WJ (Grand Cherokee) that was junk. I've had a 89 XJ, a 93 Dakota, 90 YJ, and 94 ZJ in the last five years. I've liked all my DD's, (89XJ through 94 ZJ) but the 94 ZJ was my first DD ever to have an automatic transmission. I missed the 5-speed in the other three previous DD's, (all had an AX-15) and wished I could've found a 5-speed ZJ for the right price. (They were made from 93-95, but in very lmited numbers. People who have them, think they're made of gold and will not even budge at good offers.) So after owning my ZJ for 18 months, I decided it was time to swap to an AX-15 in that.

Luckily when I picked out my ZJ I went with the 4.0L over the 5.2L. I did this primarily because I knew there were more options out there for the 4.0L as it was the flagship for Jeep for many years. I knew more would bolt to it. So I went out and found a 94 XJ at a junkyard that wanted to give me it's tranny. Got it, and the whole process began.

Pulling my 42RE (what was used behind the 4.0L in the 93.5-2004 GC's) was easy, but I ruined the transmission cooling lines while dropping it out. At this point I figured I was past the point of no return and there was no looking back.

Next, the AX-15's output has splines to the very end, the 42RE has a tapered end so Chrysler inserted a bushing in the New Process T-case to help get rid of any issues that could result. Well this had to come out.

Input shaft with bushing inside.
http://img252.imageshack.us/img252/6303/set99013js.jpg
Input shaft cover off.
http://img252.imageshack.us/img252/9944/set100013ln.jpg
A good set of Snap ring pliers are essential.
http://img252.imageshack.us/img252/174/set101016ra.jpg
Tailshaft off, snap rings off, and case about to split.
http://img252.imageshack.us/img252/6885/set103025ho.jpg
Planetary removed, hands to messy to take any inbetween pics.
http://img252.imageshack.us/img252/7091/set103038zl.jpg
That darn bushing.
http://img252.imageshack.us/img252/5698/set103041sb.jpg
The bearing that HAS to go back in.
http://img493.imageshack.us/img493/4440/set103053bv.jpg
Finally another step closer to finishing this swap!
http://img252.imageshack.us/img252/6227/set104032cg.jpg

Without the bushing out there's a 5/8" gap between the tranny and T-case when you attempt to put them together.

Next issue, pedals. Finding a stock AX-15 equipped ZJ in a junkyard isn't easy. The folks that have them want almost $150 for a set of pedals and brackets. I found that using clutch and brake pedals on the stock ZJ brake bracket works pretty good. The bolt is just right and works without any mods, although there is a hole for the clutch master that could be utilized if you had the stock ZJ pedals. I have to drill my own hole, but I'll manage.

XJ pedals in ZJ bracket
http://img497.imageshack.us/img497/4410/set96014aw.jpg
You can see the clutch master sticking through the stock location. I will move it, but haven't done so yet.
http://img497.imageshack.us/img497/7150/set96020da.jpg

I admit at this point, I'm at a standstill. I forgot to grab the flywheel shield when I was at the junkyard. I'm going back tomorrow to get it so I can get the tranny up.

I will have to get new driveshafts as my rear one will need nearly 3 more inches to work properly and the front needs 3 less inches.

In case you are wondering, this swap will end up costing me a little over $1000. I'll post a breakdown when I'm done. Cheaper than paying the $1800 to rebuild my 42RE.

Considering I'm driving up there this summer with a trailer, I thought it would be smarter to do this now, rather than wait until I got there. Not to mention, I've had decent luck getting the parts I've needed. 185K was also lurking on that tranny, and something about luck only going so far.

Good luck in your ventures turning your rig into something unique! ;D

[sevenslats]

Awesome. ChevyKev did a simialr swap in his K5 Blazer last summer. I'm kinda liking the auto I have now. I dont' have much trail time with it, but the highway ride is nice.

[AK20]

Looking good so far, wise to do it there vs here just for the simple fact that all your trips to the junkyard would be in vain here...they most likely wounldn't have what you need and if they did it would be an arm and a leg.

Geoff I think your thinking of my manual swap this summer/fall, Kevin has had his 4-speed for as long as I've known him which is well over a year and a half. Mine was easier in comparison to this jeep swap, and Kevin's matter of fact. My truck started life with a manual, but for some reason the knuckle head who had it before me swaped it out for a 700R4. Anyway all brackets were still intact, holes for the cross-member etc. all I needed was the tranny and the linkage then basically bolt her up.

[sevenslats]

Well, Kevin actully took pictures of his swap, and they're in the gallery. :P So maybe it was over a year ago.

[AK20]

I had pictures as well, but they were on a thread in 4x4 tech. Last time I checked the thread hadn't been recovered after the hack, either way good stuff.

[sevenslats]

Sorry. I have a bad memory.
BOT, looking forward to hearing woody's review of a 5-speed ZJ.

[AKJeeper]

You're definitely right about 5spd ZJ's being difficult to obtain. There used to be two on the island here, neither person would sell, and both people ordered their ZJ's new from the factory like that. There's just something about the 5spd 4.0L ZJs that makes them seem more peppy than even the V8 ZJ's. Thanks for posting up your swap pics! Here I thought I was the only one crazy enough in the US to actually ponder on swapping a 5spd into a ZJ.

My dad owns the '93 V8 ZJ that I used to have in Fairbanks. I've often thought about trying to swap an NV4500 behind it *when* the 46RH transmission in it goes bad. Wonder how fun a 5spd V8 would be to drive?

Keep the good work going man!

[AKMark]

The 4500 behind the V8 would be awesome, but the 4500 probably would not fit. You might have to use the 3550 they use in some of the newer Wranglers. I could be wrong, but there isn't a whole lot of room in there.


The tranny is in. Just got in from doing it. It's not ready to drive yet, but the tranny is definatley installed. It actually went in easier than most of the manual tranny's I've put clutches on. I'm very happy and just wanted to share my joy.

Here's the pics.

http://img269.imageshack.us/img269/4761/set105025yv.jpg
http://img269.imageshack.us/img269/6624/set105036lb.jpg
http://img269.imageshack.us/img269/838/set105047ir.jpg

I'm still waiting on my rear driveshaft. The front has an appointment with a shop on Monday to get shortened.

I'm also having to get a new floorpan with both the boots, and the T-case linkage. There's a Novak conversion for the shifter I was thinking about, but got a package deal on getting the standard linkage instead.

I'm not done with everything, but from here on, it's a one person job!

[sevenslats]

Sweet. I wish I could see the pics, but I'll check them out as soon as I get home.

[AKJeeper]

You might have to use the 3550 they use in some of the newer Wranglers.

I'd love to put a NV3550 in my '94 XJ someday. Not that the AW-4 currently in it is that bad (actually quite good for an automatic)...but there's just something about having a 5spd in a rig that makes it so much more fun.

Can't wait until you get it up and running. I'd love to hear about your driving impressions w/ the 5spd!

[nate379]

Have the wiring figured out yet??

The ECM won't like it when it see there's no auto tranny plugged into it. That's what makes the swap the hard part. Yours being OBDI though, it should be easier.
Almost not possible with the OBDII... ECM just will go in "limp home" mode.

[AKMark]

Yeah the seperate ECM/TCM makes this swap easier. The PCM used from 96-98 might have issues. But, I've looked at the PCM from a 97 and it has the same connections as mine. One might be able to swap in a computer from an OBDI and have it work well enough to do the job. Dunno.

[AKMark]

Tranny in an functional. I still have to put the boots on and get everything sealed up. Drives a lot better, although I do need a new rear U-joint. First three gears are very stout and the acceleration is impressive. I've also noticed a 3-4 mpg increase with in town driving. 13-17 is a big difference! I used to get bad vibes above 72, so I just didn't drive more than 68 and it wasn't a problem. I took it all the way to 80 with no vibes and wow was it nice.

I'll post up pics and cost in a couple of days when I get the cosmetics and math figured out.

[sevenslats]

Congrats. Glad it is working, and benneficial. I'm looking forward to seeing pics of the mounts and crossmember.

[ChevyKev]

Good work! 5 speeds on hwy tend to get me in trouble! :police:

[AKMark]

Well folks the day has come. My swap is now complete and there's nothing left to do. It took three weeks, many scrapes, and my savings account, but it's done.

Here's the damage not including the parts I bought that I did not need.

AX-15 tranny $275 From a 94 XJ 4.0L 82,xxx miles. Rear end collision. Junkyard purchase, traded 42RE for the core. Came with bellhousing and shifter.

AX-15 tranny mount (Rockauto) $54 (shipped) Looked up M/T mount and there it was. Fit perfectly on the stock crossmember.

Clutch kit $142 Napa Gold for a 94 JGC with a M/T (Gotta deal because father-in-law works at a Napa)

Flywheel $50 Also Napa Gold for a 94 JGC with an M/T

Clutch and brake pedals $85 out of a 88 XJ.

Clutch master cylinder and external slave (Make sure to use an external, they are sooo much easier) $75 From a 97 TJ.

Crankshaft position sensor for a M/T $62 Pep boys

Rear driveshaft $85 Needed to be 3" longer than A/T's

Front driveshaft shortened and balanced $85, it cleaned mine up good and got rid of vibes.

Shifter boots, and ZJ AX-15 T-case linkage, and ZJ AX-15 5-speed shifter/lever/knob, $100.

Bellhousing dust cover $25 (you can get these from any AX-15 equipped Jeep.)

Various hardware $35 (bolts and stuff)

Rocker switch w/cover $5

Total Damage = $1078 per my reciepts. Those prices include shipping.

Still half the price of rebuilding my auto. I would've had it built right with a shift kit and beefier stuff so it would've cost me about $2200.

It drives great, has tons of pull in 1st through 3rd, fourth and fifth are pretty much the same as third and fourth on the auto, except you don't have a torque converter doing it's own thing and I can accelerate from 40 mph in 5th gear without shifting. I filled up this morning after putting 200 miles on since my road trip after getting it running and my in town average was 17.9 miles per gallon. I normally get between 13-15, usually closer to the 13, so big savings at the pump. (I filled up just to see the miles per gallon on paper. The computer showed 17.5) My short clutch break in/road trip gave me a reading of around 19 even though I was flooring it and climbing steep grades and having way too much fun.

Some things I should note. Not all AX-15's are the same. The ones used prior to 1994 have a different input shaft, with the exception of the ones used in ZJ's. The 93 ZJ got the upgraded for 1994 version (when they were first built) and from 1994 till 2000, everything is pretty much the same.

The tranny mount in the GC is somewhat different so please order a new one when attempting this.

I never suggest using a used flywheel and clutch, (I've worked on this stuff before) but if you are going to go that route, a 94+ XJ or a TJ have the same stuff, so you can use one of those.

Clutch and brake pedals. You can go two routes with this one. TJ and YJ pedals and their brackets do not fit. (ASK ME HOW I KNOW) The XJ bracket will also not fit. (ANOTHER WASTE OF GOOD MONEY) You can do two things without building your own. First, find an AX-15 equipped ZJ in a junkyard (they are on Car-part.com, but you won't find those listed, you have to search for other parts that are AX-15 specific, like driveshafts and call the yard to see if they have what you need), they will run you between $150 and $125 not to include shipping. A set of XJ pedals works great if you put them in your stock brake bracket. I didn't think it would work, but it did. I did RTV a nut onto my brake switch, otherwise the pedal would not have made contact with it. Works great though and cost me less than ZJ specifics.

The clutch master cylinder from an XJ or ZJ is the best. They use a remote reservoir which helps with space in this area. 93-95's have the hole already there, you just have to remove an inspection plate to open it up. The clutch master should be connected with a line to the clutch slave. Don't let anyone convince you they come seperate. Once the line has been disconnected, the slave is no good. You can get a new line on the master, but not the slave. I used a TJ's Clutch master and it worked, but will be hard to add fluid to in the future.

The CPS from the auto will not work. Go out and buy the one you need.

It would've cost about $180 to lengthen my rear driveshaft, so I found one used on car-part.com for $85 shipped and it worked perfect. Again, ZJ AX-15 equipped is the requirement.

Having the front driveshaft shortened, balanced, and pretty much overhauled was at least $50 cheaper than buying another one that had been in a junkyard for years.

The AX-15 T-case linkage attaches to the tranny in a vertical fashion. The 42RE's linkage attaches horizontally, so they are incompatable. Novak conversions makes a nice setup I thought about going with, but I got a good deal on shift boots plus all the stock ZJ AX-15 linkage, so I went with it. A XJ or TJ linkage might work, I never compared them to see if it would.

Bellhousing dust cover, you wouldn't believe how many places just scrap these when they pull the tranny. It was hard to find, you can get it from a dealer for $45 plus tax, but I found an XJ that didn't need it anymore.

I needed bolts, as the tranny didn't come with the bellhousing bolts and I needed longer ones than the auto used. So yeah, the folks at Ace hardware got to know me pretty good.

When you do this you have to ground the neutral safety switch, otherwise, the Jeep will not start. When you ground the switch, you have no cruise because the vehicle believes itself to be in either park or neutral. To alliviate this problem, I used a rocker swith with a cover. (See above pics) I put it in one position to start, and another to use the cruise. Works great. I could've hooked up the harness on the Clutch master Cylinder, but I like being able to start out in gear if I want to.


If you have any questions, feel free to ask.


Sorry for the crappy pics, the Kodak is not working. My Palm pilot leaves things to be desired definately.

http://img317.imageshack.us/img317/6708/set88016in.jpg
http://img317.imageshack.us/img317/4386/set89010pu.jpg
The AX-5 or wrong tranny. Note my new clutch in the backround.
http://img317.imageshack.us/img317/7877/set88037ln.jpg
The AX-15, or correct tranny.
http://img317.imageshack.us/img317/7253/set88028ut.jpg
Flywheels. The one of the right is for the auto and weighs about five pounds. The one on the left weighs about thirty, gotta have room to grind it down later on I guess.
http://img317.imageshack.us/img317/3340/set88040uw.jpg
Old shifter mount, I decided to just cut a hole and ended up using the stock ZJ boots to cover it.
http://img341.imageshack.us/img341/5858/set90016xn.jpg
Yes, after destroying some dremel disks, I used my drill and made more holes than I could count.
http://img341.imageshack.us/img341/8091/set92010xe.jpg
http://img341.imageshack.us/img341/5506/set93020xi.jpg
It's out!
http://img341.imageshack.us/img341/9489/set94011ug.jpg
Note the red wire coming through the hole. It's the NSS wire.
http://img370.imageshack.us/img370/8295/set106014eq.jpg
http://img453.imageshack.us/img453/6727/set108011ce.jpg
http://img453.imageshack.us/img453/5658/set108029jt.jpg
http://img453.imageshack.us/img453/4710/set106022na.jpg

[4x4_MMMH_4x4]

++++ man, really impressive, it looks amazingly stock*thumbs up* you did a really nice job, sucks you went through dremel bits though >:( cant wait to see more of this thing soong!!!

[AKMark]

I guess I'll just have to take you for a ride first. ;D

See you in June!