Gathering 5 speed swap parts, need some help

[Agreen]

1998, 4.0 vehicle. Originally 2wd auto, I swapped it to 4wd auto a few years back and I even rebuilt the AW4 while I was there. I also added a Transgo HD-2 kit. Works perfectly fine, and has for over 20k miles and 4 years. But I have been itching for a 5 speed and they're so incredibly hard to find. Especially in salvage yards, but from a private seller they're usually $5-600 or more.

I finally found an AX-15 in a salvage yard today so I snagged it. It came from a 90. Output shaft spline count is 23, like my transfer case input so we're good there. The driveshafts were both bent up from the forklift or something, so I'll have some driveshafts made if necessary.

So far I have:
90 transmission (with 23 spline output, yes I verified)
My 98 xfer case
The metal dust cover for between the engine and bell housing
A 98 bell housing (from a 2wd) with clutch fork
AW4 cross member (I'll be using an SYE, so I'm hoping the 1/2" height difference will be ok. If not, I'll drop it 1/2")
Brake/clutch pedal assembly from a 2wd 98 5 speed
Shifter assembly from the 98 2wd with the boot and sheet metal)

Things I think I still need:
Clutch hydraulics
Flywheel
Clutch kit
(I'm buying the aforementioned stuff new since they're wearable items)
Some wiring magic to make my ECU think the auto is still there since the 2wd 5sp ECU was already gone
Driveshafts

Anything else I'm maybe missing?

Now, as far as driveshafts go, I talked to a local that's using an AW4 front DS with an SYE (rear, obviously) and he's had no issues for several thousand miles and wheeling. His XJ is lifted 3" like mine, so I guess I'll just play that by ear when I get there.

So far I'm in about $3-400. If I end up with a CEL it's not the end of the world, I'll just keep looking for a 98 5sp ECU.

Thanks in advance

 

[Agreen]

Looks like Jeep made a change to the pilot bearing in 92. The 90 uses a .586x.827 inner/outer diameter bearing and my 98 (hopefully) has a crank pilot bore diameter of 1.000", and the inner diameter after 91 would be 0.750". So although I somehow have a 23 spline output (which I read should have been 21?) I have a smaller pilot shaft diameter.

I did find that on Novak's website they sell Part # PB-2001295, which is for Jeep 4.0L cranks (1992-2006) to Jeep AX15 (1988-1991).

So there's one issue I won't have to struggle with...

 

[Anak]

Nothing jumps out at me as being missing. Looks like you have a handle on what you are getting into.

One thing I will recommend is that when you get your clutch kit you take the throw-out bearing that comes in that kit and throw it as far as you possibly can into the middle of a large body of water. Replace that POS with a decent throw-out bearing from someone like Timken or SKF.

The bearings that come with those kits are cheap garbage and they will fail suddenly and without warning. Ask me how I know.

I think the makers of the kits are hoping that when you have to tear into the bellhousing to replace that POS you will decide that you might as well just do the clutch again since you are already in there.

Just a tip from the voice of experience.

 

[Agreen]

Matter of fact, my dad had that issue with his 04 TJ. He put in a kit and one of the tabs on the side of the TOB where it mounts to the clutch fork broke after about 5-6 months. Fortunately Perfection Clutch has a center right down the road and when he called them about it chattering, they wanted to see it in person. He drove his TJ there and they asked if they could take it apart to see for themselves. He said sure and they called the NEXT day and told him what they found and that they put a new clutch kit in for him, free of charge. Yes, there at the R&D facility. I was pretty impressed. They apologized and said they are always looking into failure points to make their products better, so maybe I'll give them a go?

Or maybe I won't take the risk and just buy a damn Timken TOB. I already know/trust that brand lol

Thanks for the look (and the words of experience) Anak.

 

[Anak]

You are quite welcome.

One other thought has come to mind: XJ clutch pedals have a failure mode wherein the factory weld gives up and allows the clutch master cylinder's point of connection to bend relative to the rest of the pedal. For many folks the quick and dirty solution is to find a socket (from a cheap set of sockets) and weld that in place to reinforce the assembly.

I hope that description makes some sense. I think if you have the pedal in hand and look at it you will see how the failure could occur. If not I will see if I can find the pictures of what I did to reinforce mine. Or you could search for the topic.

At any rate, the point would be to try to pre-empt that failure mode by reinforcing that pedal while you still have it readily accessible to work on.

 

[Agreen]

I think I found a picture on another forum. Looks like it breaks right where the pedal meets the pivot?

 

[Anak]

Yes. It just has one point of attachment, and after many years of repeated stresses the weld gives up the ghost.

The fix is to add a second point of attachment by connecting the short leg that drives the master cylinder to the long leg that is the pedal. Rather than searching for a socket that just fills that gap I cut a piece of steel bar stock to go in there.

 

[Agreen]

Ohhhhhh now I see what you're talking about! I don't have the clutch pedal assembly in front of me here. I'm on a business trip about 5 hours away from home. I had a day off today so I decided to look through the local pick-n-pull. That's when I found the (apparent) unicorn transmission that I've been trying to find (at a pick-n-pull... you know, for the pick-n-pull price). Anyway, that's why I don't have the pedal assembly here, but looking at a picture of it online I see what you mean now. Yeah, I think I can fix that pretty easily. I JUST got done making a JCR DIY bumper over the weekend before last, so this should be no problem at all.

For those who will see this in the future:

 

[Anak]

Yep. That is it. That little leg breaks or bends off from the pedal.

Just one more little point of attachment and the whole assembly is much stronger. Easiest if done before things break.

 

[lawsoncl]

I actually did the opposite a long time ago, installing a 98 AW4 in place of an 89 AX15. I recall several trips back to the junkyard for all the misc parts I missed.

I didn't realize there was a height difference between the AX15 and AW4 in the crossmember? I didn't change mine. I'm fairly sure the trans mount is different. For driveshaft lengths, the AW4 is almost exactly an inch longer than the AX15. The xfer case linkage and its mount are different between the two, although I recommend going aftermarket with either Azzys or Boostwerx setup either way.

When you mate up the AX15 to the xfer case, do some measuring. Your transfer case might have a medium length snout and the 1990 AX15 originally bolted up to a short snout. https://www.novak-adapt.com/knowledge/np-nvg-input-gears

X2 on decent throwout and pilot bearings. I made that mistake when I rebuilt the original AX15. The pilot bearing seized 30k miles later and destroyed the AX15 main input bearing. I would seriously consider a rebuild kit with new synchros and bearings. Most of the kits don't include the main input bearing, btw. If there is any yellow in the oil, or it's been run with regular gear oil the synchros are probably shot. Synchromesh, Redline MTL, or Mobil-1 10W-30 for lube.

If you can't find an manual engine computer, I would try leaving the trans computer in place and jumper the NSS connector to indicate you're in neutral. I think that'll let the engine computer see the trans computer is still alive, and the trans computer shouldn't complain about input/output speeds not agreeing with the gear it's trying to select or that the NSS input looks wrong. You might have to put some 15-ohm resistors across the solenoid outputs so it doesn't think you've got a bad solenoid (probably can go higher on the resistance).

You'll need to grab the reverse light wiring from the NSS connector.

 

[Agreen]

What I don't get is why they call the "medium" shaft rare? If it's rare, then why is it in every automatic XJ since 1990?

 

[Agreen]

Well, looks like even if my transfer case input is too long there's a solution. And I love these kinds of solutions:

https://www.stu-offroad.com//engine/aw-4/aw-4-14.htm

I realized today that while I was at the pick & pull yesterday that the clutch fork retaining spring fell out of my glove when I pulled it out of my tool bag. I looked at it and went "what the hell is that?" and kept on pulling the transmission. Later on I figured out what it was and thought that about going back, but then I'd have to waste my time driving out there AND pay the entry fee. Totally not worth it when I could buy one from quadratec for $2 plus shipping.

I just hope that I'm not missing anything stupid that will keep me from driving it once I start the swap. It is my daily after all, but such is life when you start fooling with your daily. Worst case, I'll have to ride my motorcycle in the cold.

 

[Anak]

Another detail to pay attention as you do this job: The routing of the hydraulic clutch line.

There is play in that line and room to get it too close to the exhaust. When this happens the exhaust warms up the line, softens it and then causes it to burst during a push of the clutch. Of course the line will be softest in the spot that is closest to the exhaust and this means the spray of hydraulic fluid will be aimed directly at the exhaust. And guess what? The hydrualic fluid is flammable. Yes, you get smoke and fire. Under the hood. In close proximitiy to your fuel line. Not exactly an optimal situation.

When I replaced my clutch line (after getting to experience the above first-hand, after replacing that POS throw-out bearing) I decided to wrap the section that gets closest to the exhuast in aluminum duct tape (not the fabric stuff--the stuff that is actual solid aluminum sheet and has the adhesive that instantly bonds to anything). My theory in doing this is that the aluminum will direct the leak either up or down the hydraulic line. And it should help to prevent the leak in the first place.

You only need a few inches of that tape. If you don't have access to some send me a PM.

 

[Agreen]

Yeah I'm pretty sensitive to things like hose routing. My 81 J10 caught fire a while back because of something similar. I now carry a fire extinguisher in case something like that happens again. It took the fire department over 15 minutes to respond. At that point it was too late.

 

[lawsoncl]

Well, looks like even if my transfer case input is too long there's a solution. And I love these kinds of solutions:

https://www.stu-offroad.com//engine/aw-4/aw-4-14.htm

Cool. Nice to know it's just a matter of trimming the snout and the depth of the internal splines isn't an issue.

Anyone else notice the exhaust first picture on that page? It appears to do a u-turn and then wrap around the front of the oil pan?

 

[Agreen]

Ok well everything is ordered. Clutch kit, adapter pilot bearing, flywheel, master/slave pre-filled combo, hack n' tap SYE kit, everything that I could think of remaining to finish the project.

You may ask why the hack n' tap. Well, I figure if I bust a transfer case I can swap the HNT yoke to the next t-case and go. Plus I'll already be hacking my input shaft, so I might as well do the output shaft too.

But everything else will be done right. I have some weather pack connectors to do the wiring, which will also get looked and tied back properly as well. I have all the right bolts for the bell housing, clutch pressure plate, and flywheel bolts. I didn't order anything for the transfer case shifter yet. I kind of want to see how it all lines up. I might just modify it myself if it's not gonna be too crazy.

I have 2 shifter housings, both have crumbled bushings. The seal is ripped too, so I'm looking for those hopefully as a kit.

 

[Agreen]

And I found it. Bushings and lower seal boot ordered!

 

[lawsoncl]

I didn't order anything for the transfer case shifter yet. I kind of want to see how it all lines up. I might just modify it myself if it's not gonna be too crazy.

From my vague memory of my swap ages ago - The automatic version of the xfer case bracket was 3" longer, and the pivot attached to the body 2" further forward? You could certainly lengthen the the exiting bracket and rod by an inch. There is a dorman part number to replace the bushing in the shift linkage for something like $6. I've heard the material is very stiff and hitting them with boiling water to soften them before pressing them in helps.

One nice thing about going aftermarket right away is not having to wrestle with the xfer case nuts behind the stock bracket.

 

[Agreen]

I need to figure out how to keep cruise control:

The speed control can be disengaged manually by:
• Stepping on the brake pedal
• Depressing the OFF switch
• Depressing the CANCEL switch.
The speed control can be disengaged also by any of
the following conditions:
• An indication of Park or Neutral
• The VSS signal increases at a rate of 10 mph
per second (indicates that the co-efficient of friction
between the road surface and tires is extremely low)
• Depressing the clutch pedal.
• Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
• The VSS signal decreases at a rate of 10 mph
per second (indicates that the vehicle may have
decelerated at an extremely high rate)
• If the actual speed is not within 20 mph of the
set speed

So if I trick the ECU into thinking the AW4 is there, I'll need to wire the NSS to the clutch switch. If I do that, it will think I'm in park or neutral while driving (clutch engaged) and the cruise control won't work.

 

[Anak]

Clutch switch?

Interesting. I guess in '97 they started incorporating a clutch safety switch.

My '96 does not have one.