AW4 Interchange

What's up fellas?

I'm looking to swap in a 91-95 AW4 into my 90 Renix. I do know about the spline change so I'll need the donor trans' respective T-case. My questions are will I need to reuse my CPS and NSS?
Does the TCU harness plug & play?
Are there any known TCU changes throughout 87-95 (software changes) besides the pwr/cmft switch?
TIA, Adam.

everything is plug and play (aside from spline count) from 87 to 96. the one thing that might be an exception would be how the cooler lines attach.

I put a '95 AW4 into my '90. The '95 is a 23 spline so I had to change the inpuit gear on my T-case. Evrything else was a plug n play. Im not sure when they went to 23 spline.

The Kickdown Cable on a 91+ is different.
Cooler lines attach the same.
Isnt the Renix T-case vacuum actuated or something like that?
(I know it has vacuum lines running to it)

the vac lines are for when there's a vac disconnect d30 axle. they operate the axle, the t-case is mechanically actuate.

You'll need to use the renix flexplate and CPS to match the engine computer. Bellhousing, tc, etc should bolt right up. I think the NSS connector is the same. Your older NSS should bolt right on, though you might want to disassemble and clean it first.

I think the connector that has the solenoids and rear speed sensor wires is the same up until the AW4 changed in 96+. In 96+ when they went to the ODB-II engine computers, the rear tranny speed sensor changed type and pulses/rev, plus they added a front speed sensor. Worst case you either swap wiring harness (need to drop pan to unhook at the solenoids) or you cut and splice the old connector onto the new harness.

You should be fine keeping the 90 TCU. I'm not positive, but I think you can use the 91-95 TCU as the connector pinouts are the same. Again, the 96+ changed connector and sensors. In the later, non-Renix systems, the TPS signal comes from the ECU instead of a dual output TPS and the diagnostic outputs go to the ECU instead of the big yellow connector under the hood.

When I swapped in a 99 AW4 into my 1989 MJ with a nuked AX15, I found everything pretty much bolted right up. I'm pretty sure I used the 1999 tranny cable (not kickdown), but I don't recall what year donor I grabbed the throttle body bracket from. Cooler lines snapped right in as well. My only real issue was getting an 89 TCU to work with the 99 rear speed sensor which I solved with some fancy, homebrew electronics wizardry.

Thanks for all the helpful replies! I take it the only thing I will need to grab from the 91-95 is the kickdown cable?

Count the output splines one the trans. '95 is 23 and your '90 is 21 so it won't fit. On this site it says that the AW4 went to 23spline in '91. http://www.novak-adapt.com/knowledge/np231.htm Manual tranniy T-cases are different and might already have a 23spline.

If you upgrade your NP231 T-case to a 23spline here's how to do it. Then you can use the '91-'95 AW4's. Or get a matching 23spline T-case.
http://www.4x4trailhunters.com/article.php?id=20

You will need to use your renix CPS. The NSS is interchangeble to '95+

Just finished stuffing the COMPLETE drivetrain from a '98 into my '88 Limited. The biggest headache with the tranny was for the speed sensor thing on the tailshaft housing. The really late model AW-4 uses a 4 "lobe" trigger device, while the earlier models use a 2 "lobe". You simply remove the tailshaft housing, snap ring retainer, and "lobe" , then replace with the earlier model pieces. You will also have to drop the pan to switch the wiring harness on the solenoids. Disregard the sensor up at the side of the bellhousing, as the older TCU does not use it. The cable going to the throttle body is ALOT longer, so either switch it, or figure out some way to secure it. One last thing to watch out for: the bracket on the side of the tranny where the shifter cable hooks up is ANGLED differently, if you try to force it to work on the older cable, YOU WILL END UP BREAKING THE PLASTIC PIECE ON THE END OF THE CABLE. ( Ask me how long it takes to replace THAT stupid thing.)

ren said:

Just finished stuffing the COMPLETE drivetrain from a '98 into my '88 Limited. The biggest headache with the tranny was for the speed sensor thing on the tailshaft housing. The really late model AW-4 uses a 4 "lobe" trigger device, while the earlier models use a 2 "lobe". You simply remove the tailshaft housing, snap ring retainer, and "lobe" , then replace with the earlier model pieces. You will also have to drop the pan to switch the wiring harness on the solenoids. Disregard the sensor up at the side of the bellhousing, as the older TCU does not use it. The cable going to the throttle body is ALOT longer, so either switch it, or figure out some way to secure it. One last thing to watch out for: the bracket on the side of the tranny where the shifter cable hooks up is ANGLED differently, if you try to force it to work on the older cable, YOU WILL END UP BREAKING THE PLASTIC PIECE ON THE END OF THE CABLE. ( Ask me how long it takes to replace THAT stupid thing.)

Click to expand...

I ran into the same sensor issue, but found out after everything was together. I was a bit confused when it kept upshifting at 1200 rpm. I built an electronic box to convert the 4 pulses/rev from the inductive pickup (puts on ac voltage spikes) to the 1 pulse/rev that the old magnetic switch put out. Looking at the FSMs from the two different years it looked like I could swap the rotors if I had a donor. Nice to know it can be done. I swapped the solenoid harness for the older style while I had the pan off to replace the filter. I didn't run into the shifter cable problem since I swapped the lever with the shifter cable. I do remember it was very long and a bitch to route. Not like the real short one on my ZJ.

The AW4/242 swap works out great! The 23 spline 92 trans/T-case combo I used works out wonderful in my 90 Renix. The only things I had to swap over were the CPS as the Renix is 2 pin and the 91+ is 3 pin and the bracket where the shifter cable connects to is different (swapped over). Overall driveability is the same except for the higher 4th gear ratio which turns a tad higher on the tach at the same given speed.

AW4 swap

Strangest CPS (renix)I've ever seen.