Ditching Peugot for AW4 Auto, Need Help!

Ok I am in the process of replacing my my 5spd Peugot with an AW4 in my '89 XJ Larado.

I have a complete '89 Wagoneer/XJ(no rear D44 ) that I am using as a donor. It had a rebuilt engine in it as well so I am going to swap the whole drivetrain from motor to t-case. So far I have the driveline out of the Wagoneer.

How hard is it to swap over the electronics for the AW4? I know there is TCU behind the glove box that I need as well as the TPS. Anything else electric wise? Can I swap just the wiring for the tranny or will I need to change out all my wiring?

Anyone have a diagram then could send to me? [email protected]

Also my rad has the ports for the tranny cooler but do I need an AUX cooler as well? I don't tow with it just trail riding(31" tires and 4.10 axles)
Thanks a lot!

the TCU should be under the passenger dash, below the glovebox. no need to pull the glove box out

yes the TPS is different. i'm thinking there is something else too, but i'm not at my normal computer that i have all my wiring diagrams and jeep info on. but it's still a fairly straight forward swap.

an auxillary cooler is always a good idea, heat kills autos. for 31s with 4.10s, and basic trail rides you'll probably be good enough with just the rad. cooler. however the older closed radiator system may not be up to the cooling task, especially when you add in tranny cooling. this would be the perfect time to upgrade to the newer (91+?) open cooling system with a 3 core radiator. it can all be done for $2-300.

Actually I have already converted to the open system. Last time I replaced my rad it came with a filler neck but still had the ports for the temp swtich for the aux cooler so I did not need to replace the t-stat housing or mess with the wiring. All I had to do was replumb some of the heater coolant lines to eliminate the pressure bottle. Unfortunatly a three core was not available so I just got a two core but it seems to be working ok. I will definatly be adding an aux tranny cooler down the road though. Just am already over budget right now. Decided to replace the steering box since its nice and easy to get to with the engine out.

The wiring doesn't look too bad either but I will have to replace the main engine/tranny harness under the hood with the one from the donor. Doesn't look too bad though, everything seems to unplug and all the plugs are different so I can not confuse them. Except for the ones for the fuel injectors, those I labeled.

Thanks for the info. Time for me to get back out there and pull some wires!

I did this exact swap in my 89 XJ a couple of winters ago........great mod!!
I snagged a donor 96 AW4 with 40k miles for my swap, and a spare engine compartment harness from an 88 rig. If you have the donor rig, you may just want to swap the complete harness from one to the other, but compare the wiring of the two and make your call.
I have schematics and some tips so hit me backchannel with your email addy.

[email protected]

Yep I pulled the engine compartment harness out today, was fairly easy. What took longer than I thoguht it would was removing the shift tower and cable. That darn cable was snaked up way under the dash and I had to remove the brake pedal bracket to get it out! But its all out now and lying on the garage floor. Tommorrow I will start pulling the drivleine from my XJ.

XJEEPER you mentioned swapping the whole harness. Do you mean just the engine compartment harness or the whole vehicle? I can be e-mailed at [email protected]
if you could send me those schematics and tips I would appreciate it. Thanx again.

keep us updated on how it goes....i am going to do this as soon as i get a job and another car to drive. soooo tired of this Peugeot...

-J

I'll do that, its part of the reason I started this thread. I did a search and found that others had done the swap but I did not find much actual technical info.

Me and my dad are doing a similar swap, only cherokee to a sporttruck. What we have done so far is pull the drivetrain out of both rigs and are going to start the swap, the motor compartment harrness went in with no trouble. Ever thing pluged in just fine. Does your drivetrain have the 242 or the 231 we've got the 242 and the rear shaft is about 6 inches shorter then the old one, out of the sporttruck. Heres one for you guys we pulled the valve cover off the donor and there was a black mountain of goo between the valve spring, but when you smashed it between your fingers it would just rub away and have a clay feeling to it but it smelled like used oil. Now where did that come from?? Any way good luck with the swap let me know if you have any problems that I can avoid and I'll do so to you to.

I'm was getting ready to pull out the drivetrain today but got distracted so hopefully it will come out tommorow.

I have noticed that there is a difference in the wiring regarding the plug for the CPS. On my XJ(originally 5spd) the wires for the CPS split off the main loom on the engine side of the firewall and and the donor(originally automatic) the wires split off under the dash and then go thru the firewall in its own gromet completly seperate from the engine compartment wiring harness. Anyone know why this is? Looks like I may have to do some minor splicing. Not to thrilled about it as any extra resistance in the line could affect the reading from the CPS.

Not too sure about the sludge in your engine, it probably just wasn't maintained very well. Infrequent oil changes. Sounds like oil that got old and hot then broke down.

My XJ oringinally had a NP231 in it but I swapped in a 242 about a year ago. I noticed that the automatics use a shorter driveshaft than a 5spd as an AW/4 is slightly longer than a Peugot. But I know for a fact that an MJ has a longer wheelbase than an XJ which is probably where your discrepency is coming from. Not so much the tranny/t-case but the actual wheelbase. You will probably either have to get a custom driveshaft made up or find a driveshaft from an MJ at the junkyard with an automatic tranny. Shouldn't matter if its got a 231 or 242 as the two cases are identical in length. Did you notice that the crossmember on the automatics mounts about 6" farther back than the 5spds crossmember? There should be an extra set of holes drilled in the unibody for this but they will probably need to be tapped/cleaned.

cLAYH said:

I'm was getting ready to pull out the drivetrain today but got distracted so hopefully it will come out tommorow.

I have noticed that there is a difference in the wiring regarding the plug for the CPS. On my XJ(originally 5spd) the wires for the CPS split off the main loom on the engine side of the firewall and and the donor(originally automatic) the wires split off under the dash and then go thru the firewall in its own gromet completly seperate from the engine compartment wiring harness. Anyone know why this is? Looks like I may have to do some minor splicing. Not to thrilled about it as any extra resistance in the line could affect the reading from the CPS.

Did you notice that the crossmember on the automatics mounts about 6" farther back than the 5spds crossmember? There should be an extra set of holes drilled in the unibody for this but they will probably need to be tapped/cleaned.

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Jeep issued a CPS wiring kit that replaces the original wiring from the CPS to the ECU. This came with it's own little grommet and instructions on how to retrofit it into the original ECU plug. Sounds like this upgrade was installed on your rig sometime in the past. It shouldn't be a huge issue to rework this.

As for the tranny mount, yes the AW4 mounts further to the rear of the unibody, just tap the rear holes and bolt the crossmember back up. BTW, I tapped all 4 holes to an SAE thread to accomodate larger bolts (just happened to have the tap handy in my toolbox, don't recall the size).

XJEEPER said:

Jeep issued a CPS wiring kit that replaces the original wiring from the CPS to the ECU. This came with it's own little grommet and instructions on how to retrofit it into the original ECU plug. Sounds like this upgrade was installed on your rig sometime in the past. It shouldn't be a huge issue to rework this.

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Ok I was wondering about that. It was actually done to the donor rig and I wasn't quite sure what was going on as I could see the original plug there as well. What was the purpose of the mod? Since the original plug is there I may just use that and save myself some time drilling the firewall and splicing.

What about the power comfort switch? I'll probably just wire it so that its permanently in the power setting but was wondering where the wiring for the swt came from, the engine compartment harness or the under dash harness? Hmmm, I guess it must be the under dash harness since I don't remember unplugging it when I removed the engine compartment harness. I'll have to look and see if the 5spd under dash harness has the plug for swt. No big deal if it doesn't I'll just find the wire for it at the TCU and splice in there.

I actually had my crossmember bolts strip out on me so I welded some 7/16" nuts to some 3/8" plate and then welded the plate to the bottom of my frame rails. Worked great, I used all grade 8 stuff and it gave my crossmember a 3/4" drop which iliminated the minor rear driveline vibes I had. I tried to tap the original holes out to SAE but there wasn't enough meat there to hold. Also I was worried about the nut breaking loose inside the frame rail. The really annoying thing is that I had just finshed replacing the floor pan and with the floor pan out I could have easily welded new nuts inside the frame rail.

How are things goning?? The bomb proof motor mounts are done, so were goning to drop the motor and all in tomarrow, hope that all works. I do have a qusetion, do I realy need the cable that goes from the shifter to the streeing columb? The donor XJ has curse control, the cable that goes to the columb, has an electrial pulg that runs to the fuse box and in to the motor compartment. Do I in this? Were NOT going to have cruse on the truck, will the trany still work without the cruse? I'm not affarid to not use it if the trans will work fine. Please help! Thanks Triple 4

Hmm not too sure what cable you are reffering to. On my rig I have two cables coming from the shifter. One snakes its way up behind the dash thru the firewall up on the extreme left and then down to the tranny for shifting the gears. The other goes up to the steering column and is for the shift interlock to prevent shifting the tranny out of park when the ignition is in the lock postion. I'm not bothering with this cable. The only interface I know of that the tranny has with the cruise control is thru a switch on the brake pedal to turn off cruise if you hit the brake. The switch is different on the autos and standerds as is the brake pedal. Hope this helps.

Today I put in the new steering box and swapped out the engine compartment wiring harness. The harness went fine everthing seemed to line up ok and plug in, no extra plugs.

The steering box was not so good, two of the bolts busted off when I tried to remove them and then the spacer between the box and the frame was frozen to the broken off bolts. After I got the box out I heated the bolts and was able to get everything apart. I have NEVER understood why manufactures feel the need to put aluminium and steel next so each other so they can react and fuse together! Needless to say everything went back together with lots of copper coat and new bolts!

Tommorow I'm hoping to get the shifter and brake pedal swapped out and then I can put the driveline back in maybe on Sunday? We'll see how it goes. Looks like there maybe some wiring to figure out with the brake pedal. Oh ya I also have to pull out the clutch master cylinder and plug the hole in the firewall. It will be good to yank that leaky ba#$%^d and not have it dripping all over my fuse box anymore!

cLAYH said:

Ok I was wondering about that. It was actually done to the donor rig and I wasn't quite sure what was going on as I could see the original plug there as well. What was the purpose of the mod? Since the original plug is there I may just use that and save myself some time drilling the firewall and splicing.

What about the power comfort switch? I'll probably just wire it so that its permanently in the power setting but was wondering where the wiring for the swt came from, the engine compartment harness or the under dash harness? Hmmm, I guess it must be the under dash harness since I don't remember unplugging it when I removed the engine compartment harness. I'll have to look and see if the 5spd under dash harness has the plug for swt. No big deal if it doesn't I'll just find the wire for it at the TCU and splice in there.

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As I recall, there was a suspected wiring flaw by Chrysler, thus the replacement wire to the ECU plug.
With the Power/Comfort switch, Power makes me comfortable so I just built a short jumper wire with 2 male blade terminals and plugged them into the switch socket that I left tucked up under the lower dash area. It allows me to choose between modes, but I've just left it bridged for Power. It was part of the TCU harness, IIRC.

Leaky clutch cyl? Yah, I'm really missing those!! Cleaned my fuse box out twice in 18 months, and I used Jeep/Crown units too!

Well not to much progess today just alot of little stuff. We where going to try to put the motor in but some other things came up and we ran out of time. Tomorrow is the big day. Just thought that you all might want to see what we're working with. Here is a link to my pictures: http://photos.yahoo.com/triple4x4 the gray xj is the donor, the truck is the getter and thats the motor combo thats going in the truck. The red xj is mine thats the one that I put the 2.5 from a 2.8. Those black things are our bomb proof motor mounts. That other MJ is for sale if anyone is interested let me know. Hope that you all like. Triple 4

Sorry I have not updateed this recently, I got a bit side tracked. We have a baby coming in June and wht wife said if we didn't get some things done around the houseshe was going to explode!

Anyway everything is bolted into place and hooked up. Just have to pour the fluids in and stuff some of the wiring back under the dash. Also have to find the wiring/plug for the Power/Comfort SWT. Someone said it was in the TCU harness but I didn't see it. I'll have to back trackl the wiring on the donor.

I'm REALLY glad I had a donor to use for this swap. There were SOOO many things that I didn't even think of. The latest was the exhaust downpipe. Also handy seeing where everything went.

Well I should have it running tonight. Then I can T/S all Saturday because Sunday is Wheelin day!

Good For You! Hope that verything wasn't that stressful! We got your motor and drive train in, hooked up and fired up, running like a dream! We tuff truck her tomarrow, hope everthing goes right. WE could not figure out what to do about the fork in the front end, you know how it works on vacum and all. So we were thinking on ways to fix that, one was to get some threaded rod and fix the fork into place, the other one and the one we went with was weld it. I took it to a buddy and he welded it, he also has a plasma cutter if you dont know what that is, it heats up compressed air to I think, 3000 degrees +, thats the way to cut ot the fenders! She looks good, right now it over at this grils house getting painted, nothing to special, just a few things, I'll haaave pictures to marrow for you all to see. Any was good job on compleating the swap! Triple 4

Awhile ago I had plumbed a vacumm switch in the cab and manually controlled the front axle that way so it wasn't a issue for me. I have also taken the shift motor apart a piled washers between the fork and the housing to keep it locked up. Weld works as well.

We have a plasma cutter at work. We use it to cut 1" thick plow blades with. Works way nicer than gas. Does a great job of gouging as well without nearly as much smoke and fumes.

Everything is in and working and seems allright. Turns out the wiring for the Power/Comfort Switch was there all along so it was easy to swap in. Was just going to just jumper it but adding the switch only took another 5 mins so I did it. Wow she sure revs high with your foot into it! I also noticed driving around town that the rear lockright was much better behaved. Not nearly as much bucking, lurching and squaking as with the manual tranny.

I ended up having to do a T-case drop as the shorter rear drive shaft was causing excessive vibes. I'm running a 4.5" lift with no SYE. I have extended shackles in the rear that point the rear diff up slightly. With the manual tranny and longer shaft I had minimal vibes but the longer tranny and shorter shaft made for some nasty vibes so I drilled some holes in some 1" square box tube and used some longer bolts. This seems to have fixed the problem for now but I'll have to address that before I go any higher on my lift.

Well I should go pack the Jeep for the run tommorow. Hopefully everyting holds together.


Oh, one question, how do you remove the handle from the end of the shifter? The shift indicator to tell you what gear you are in is all busted so you have to guess. Not a big deal but something I'll probably pick up next time I'm at the wrecker. Just need to know how to get the hand grip off so I can get the indicator plate off. Thanx.

I 'think' you put the lever in the 1-2 position and simply pull up.

Wel its all done and I have had it out for a test run. First thing I noticed was that I had a lot of rearend vibes. Thought it was the driveshaft but as it turns out the rear pinion bearings were shot. One was so bad that when I went to pick it up off of the bench the cage lifted right off! And of course when I pulled the axles the brakes and axle seals/bearings were bad as well! Very frustrating but all good now!. Next weekend is a long weekend here in Canada so I'll be out trying it out.

On a sided note the T-case I installed was an NP242. I installed all of the wiring that came with it(plugged right, its part of the tranny harness) and I installed a bulb into the dash and now the little green indicator light in the dash for 4wd full time even works!