Everything you ever wanted to know about the AW4

[lawsoncl]

Originally Posted by Agreen

If you do, I'm curious as to what the output shaft spline count is. I kind of wonder if it's as easy as cutting it down and bolting on the extension housing to make it 4wd. I never really could get a straight answer from all the internet searches as to what the spline count was. I have long since tossed the old transmission.

Spline count should be the same. 23 splines unless it's from an older Renix which would be 21 splines. As I recall the 4wd shaft is about 7" shorter and the gearcut for the speedo, and rear bearing are in different locations.

[Agreen]

This was taken when I built my 2wd unit with the 4wd output shaft. I didn't count splines, and I tossed the 2wd shaft in the trash immediately after this.

The point is, I'm REALLY sure you can just look off the 2wd shaft and bolt on the 4wd extension housing, then bolt up a transfer case. I swapped the output speed sensors since the one on top (the 4wd) is the older 1 pulse/rev sensor, but I was able to slip it off one and right on the other one, snap ring and everything. I'm pretty sure it would make a 4wd swap just so much easier, especially if your current 2wd transmission works.

[kastein]

Funny thing about that. I'm not sure of the 2wd output spline counts either, but you have chosen the perfect time to bring this subject up as I'm about to 4wd swap my 88 MJ which is 4.0/auto. I'll have to count the splines as soon as I drop the driveshaft, because if it's 23 or 21 I will be doing exactly that. I really hope it's actually 27 because I have a perfect use for the extra spline section in mind (long story... Part of an experimental aircraft I want to build with Subaru, Dodge, and Jeep parts) and it looks like it's long enough for what I've got planned.

It's interesting that the splines are partially regular involute and then go to the OD ground style that's used on slip yokes to match the driveshaft slip yoke.

Oh, did you compare the bore diameter in the extension housing for the output speed sensor by any chance? I seem to recall that the 98+ variable reluctance types use a different hole size from the 97- reed type, but I'm not 100% on that and all my 98+ stuff is gone at this point aside from a pile of TCUs and interior panels.

[Agreen]

So while I don't know the exact year of the transmission I got, I did swap the reluctor ring AND sensor from my 2wd shaft and tail housing to the 4wd shaft and extension housing. So it's the same bore diameter. I just wish I had counted before tossing it.

[Agreen]

I'm hopefully going to the JY tomorrow, so I'll slide a driveshaft out of a 2wd and count splines. That's if the weather holds out.

[lawsoncl]

Originally Posted by Agreen

I'm hopefully going to the JY tomorrow, so I'll slide a driveshaft out of a 2wd and count splines. That's if the weather holds out.

Googling the slip joint for the 2wd AW4 comes up with Crown 83503593, which says 28-spline. Comparing photos above the 2wd looks to have more splines too.

[kastein]

I talked to Cal about this today on Facebook and he says that 2wd are definitely 27 spline output. Kind of considering seeing if I can just cut it down and stuff a 27 spline Chevy np241 gear into my tcase, I'd rather not swap the trans if I don't have to. Just not sure if I've got a 231J from the same side of the 94 gear tooth profile change as the 27 spline input I've got.

My 2wd aw4 info is sadly lacking compared to 4wd ones, at least so far. Once we've verified things well enough in this discussion I'll update the OP with the conclusions.

[Agreen]

It's 27 spline

[Jethrodaredneck]

I've read it several times and only part I can come up with that pertains to me is on pg. 35 where the guy swapped a 98 setup in to a CJ I could be mistaken on what the recipient vehicle is. I'm in a kinda similar situation. I had a 99 XJ 4.0 with the AW4 4x4 well I rolled it 2 days before Christmas I have a 96 4.0 3vwheel drive that hadn't started in 11 years got it running and it was idk lacking nothing like my 99 so I swapped engine tranny t case rear end. The problem I'm having is it's taking off in 3rd it feels like. So I grabbed the tcm out the 99 I have the pin outs for both tcm's thingy is I have the NSS off the 96 on my 99 tranny long story. My question is when I go to wire it up there's more wires on my 99 tcm ie.iss and such so how would I go bout that in respect of still using my 99 and the 99 tcm would I need to do as that guy and grab the harness off a 99? Sorry it's just this has been a week now of me going through everything wiring something up it not work redoing it abd such any help would be great thank you

[Jethrodaredneck]

Sorry supposed to said 96 4.0 2 wheel drive stupid screen is cracked

[lawsoncl]

Originally Posted by Jethrodaredneck

I've read it several times and only part I can come up with that pertains to me is on pg. 35 where the guy swapped a 98 setup in to a CJ I could be mistaken on what the recipient vehicle is. I'm in a kinda similar situation. I had a 99 XJ 4.0 with the AW4 4x4 well I rolled it 2 days before Christmas I have a 96 4.0 3vwheel drive that hadn't started in 11 years got it running and it was idk lacking nothing like my 99 so I swapped engine tranny t case rear end. The problem I'm having is it's taking off in 3rd it feels like. So I grabbed the tcm out the 99 I have the pin outs for both tcm's thingy is I have the NSS off the 96 on my 99 tranny long story. My question is when I go to wire it up there's more wires on my 99 tcm ie.iss and such so how would I go bout that in respect of still using my 99 and the 99 tcm would I need to do as that guy and grab the harness off a 99? Sorry it's just this has been a week now of me going through everything wiring something up it not work redoing it abd such any help would be great thank you

Starting in 4th is usually indicative of no power to the TCM, a bad #1 solenoid, or wiring issue. I'd suspect a wiring issue since you swapped the tranny and would have had mismatched connectors?

Yes, the TCM needs to match the transmission because the output speed sensor is different (see somewhere above in the long thread about the problem and ways to remedy that if you have a donor). Yes the NSS is also different and needs to match the TCM, although I think it will just throw a code for bad NSS and still shift okay. You'll also find the 99 trans has an extra input speed sensor on the front drivers side that the 96 doesn't have.

[Jethrodaredneck]

Originally Posted by lawsoncl

Starting in 4th is usually indicative of no power to the TCM, a bad #1 solenoid, or wiring issue. I'd suspect a wiring issue since you swapped the tranny and would have had mismatched connectors?

Yes, the TCM needs to match the transmission because the output speed sensor is different (see somewhere above in the long thread about the problem and ways to remedy that if you have a donor). Yes the NSS is also different and needs to match the TCM, although I think it will just throw a code for bad NSS and still shift okay. You'll also find the 99 trans has an extra input speed sensor on the front drivers side that the 96 doesn't have.

Yeah I seen it had the extra sensor which I thought might of been my issues that's why I'd grabbed the tcm from the 99 but when I went to wire it up I looked at the pin outs from both years for tcm and not quite sure how I'd wire up the ISS signal and ground wires I'll look for the part you're talking bout with the using the donor preciate it

[halmca]

Originally Posted by Tim_MN

The simplest and cheapest approach is to sell what you have, and buy what need.

Where the heck were you when I began my '98 2WD to 4X4?

[halmca]

Note to all: if you are about to install an AW4 that lacks an input shaft speed sensor into a jeep that left the factory with an AW4 that DID have an input shaft speed sensor, forget it. It isn't worth the trouble. The presence or absence of an ISS is just the beginning. There are other differences as well and it's not just a matter of soldering a few wires to fix it.

Exception: if you plan to install a manual electronic control of the AW4, you might be OK. But I wouldn't do it.

The OP in his first post addresses the futility of installing a '97 transmission into and '98 jeep. Check that out before you proceed.

BTW, I have a fresh, professionally rebuilt '97 AW4 on my shop floor ready to go. $650 in North Florida. It's there because I didn't run across this thread until it was too late.

[R6TeXJ]

Originally Posted by halmca

Note to all: if you are about to install an AW4 that lacks an input shaft speed sensor into a jeep that left the factory with an AW4 that DID have an input shaft speed sensor, forget it. It isn't worth the trouble. The presence or absence of an ISS is just the beginning. There are other differences as well and it's not just a matter of soldering a few wires to fix it.

Exception: if you plan to install a manual electronic control of the AW4, you might be OK. But I wouldn't do it.

The OP in his first post addresses the futility of installing a '97 transmission into and '98 jeep. Check that out before you proceed.

BTW, I have a fresh, professionally rebuilt '97 AW4 on my shop floor ready to go. $650 in North Florida. It's there because I didn't run across this thread until it was too late.

Dang I just spent 1500 to have mine rebuilt....