Everything you ever wanted to know about the AW4

when you say, "but you may need to swap the connector housing or shave down some polarizing tabs or something on the connector according to some. I haven't tried this myself"

this isn't internal transmission work is it? excuse my ignorance on that situation, Automatic transmission service and components, aside from the basics are fairly foreign to me. As I have said, im a fairly mechanically inclined guy.. but Automatic transmission mods will be a new learning experience

Nah, it's just a wiring harness plug under the dashboard. Auto transmissions are magical to me, I don't open them.

That price is insane imo... yards get $180 for a longblock up here and $130 for transmissions. Of course, they don't have 28k miles on them. Can you hear the jeep run before buying the engine?

The other thing is that you are probably going to need to splice some wiring to make the 97 trans plug into the 98 harness. It is fairly simple, should be 5 wires as I recall, 2 for the output speed sensor and 3 for the solenoid drives. The NSS will just plug right in. Since the old transmission is pretty much smoked there's no reason to not cut the harness off it to splice onto the new transmission so you can avoid hacking up and splicing your main engine bay harness.

Can't hear it run, but I have trust worthy people to vouch. If I can get it for an even grand, I think I will pick it up. All accessories, manifolds, motor, transmission, transfer case, etc.... with only 28,000 on it. Although your prices sound much better! I've never seen stuff going that cheap!

my '89 aw4 is on its last leg, I got an aw4 & tcase from a '97. it looks like ill have to put the NSS of the '89 on to the '97, what else will I need? thanks

I am trying to put a 94 aw4 into my 97 XJ. I already swapped out the NSS.

I know the harness coming out of the drivers side needs to be spliced, but I cannot find which of the 7 wires from the transmission to splice into the 5 on the TCU side?

pictures: http://www.cherokeeforum.com/f67/97-2wd-4wd-91-96-aw4-wiring-149847/ (not my post, but my exact question)

Thanks

Dylan

AW4 spline count

Does anyone know how to tell how many splines are on my aw4 without dropping the transfer case? its 1994 Cherokee country, the 242J that is installed has a tag that reads
242J
5209 8046
5 19 94 2
272

I also have a 231J from a 98 wrangler with a tag that reads
231J
5209 9212
1 14 98 3
272

are they interchangeable?

thanks
Dave

A 1994 is going to have 23 splines. That is several years after the introduction of 23 spline cases/transmissions.

The only possible reason it would have 21 splines is if it's a 2.5L vehicle.

Thanks, i think i may have got lucky as well because it looks like it already has a SYE, not a H"n"t unless it came with 2 fixed yokes?

I was wondering if you also had info on removing the trans fittings and replacing with AN high pressure fittings. I want to route my lines away from the exhaust but still use steel lines!

GrimmJeeper did a thread on that at one point. As I recall the fittings are an M14 thread, unsure what pitch, and are O-ring sealed to the cast housing. Earls has adapters from them to a 37 degree AN flare, probably -6 or so.

Yeah I saw it but wanted to confirm the size also that both trans lines are the same size. Ok after further investigation I have located a source locally in the inland Empire area that carries on hand 14mx1.5 to AN6 (37*?) for just over $8.00! I will be picking up 2 tomorrow!
Are the other fittings available in 45*flare better than the 37* AN, as far as additional fittings availability is concerned? In other words which is more supply and user friendly?

Anyone have a new link for the circuit that you need to make if swapping in a late model AW4 into a renix. The link doesn't work anymore.. the by lawsoncl one.

Also wasn't able to read the whole thread yet due to being at work but do you have to swap the NSS, or any other computers/sensors? My swap will be a 01 AW4/231 into an 88 with a current AW4/242 combo. I want to build the circuit vs trying to find a new tailhousing, speed sensor, and rotor. (depending whats cheaper in the end really)

Another thing I just realized is that the year of tailhousing and speed sensor stuff needed for a successful swap aren't mentioned.

OK, finally read all 27 pages and these are my understandings, please correct me if I'm wrong.

-It looks like a '97 tailhousing, speed sensor, and rotor are needed for the part swap direction.
-NSS sounds like I need to keep the entire 88 system; unbolting it from current setup and bolting it onto the new trans

-The following has been mentioned multiple times throughout the thread but is continually ignored. Sorry. Correction, the links inside your link are broken.. Someone please post the information into this thread (not a hyperlink)
Thank you for your time and knowledge but the interior links are broken and we cant use the info.

-I am now confused on the TCU portion that was mentioned a few times.. I dont know if I need to get this from the donor or not.
-I am also confused on the flex plate which was mentioned once in here...Is a new flex plate and CPS only needed on a manual to auto swap? Or will I need the donor flex plate too?

Again, my swap will be 2001 AW4/231 into a 1988 jeep (currently running AW4/242) I also plan on swapping in a '90 ECU based on cruiser54's thread for gaining a little more power from the '87/'88
http://www.naxja.org/forum/showthread.php?t=1111241
both of my T-cases (current and donor) are equip with an SYE so no driveshaft issues there.

Does anyone have the info I'm asking for in the above post? ^^^^^ And the big bold portion above is referring to the electrical circuit option info that is missing.

The circuit and a couple pictures of the are still up at

http://myplace.frontier.com/~chris83803/AW4_Sensor_Converter.pdf
(writing on left says input ranges from 0.1 volt to 30-volts)
http://myplace.frontier.com/~chris83803/board.jpg
http://myplace.frontier.com/~chris83803/box_mounted.jpg

The links changed when Verizon sold out to Frontier in my area.

I used a 90 flexplate and crank sensor. Unless yours is cracking (check it thoroughly), you can use the original.

Thanks - I will update the OP.

ae_racer, sorry I didn't answer, I had no way to get the data you needed other than following the same links you couldn't get to work.

Use whatever CPS and flexplate match the year of the ECU in the vehicle. So in your case, the one CPS and flexplate for an 87-90.

Hello all,

I did a 98 engine and tranny swap into a 97. So in the end I have a 97 jeep with a 98 engine and tranny and a 97 transfer case. I just found this thread and learned the hard way about the transmissions. I've read through a lot of this thread so far and I have an idea of what I'd like to do but wanted to run it by you guys. I think I'd like to do the circuit board that lawsoncl posted. It doens't look too hard. But I'm wondering if there's more info somewhere about it? The 4 wires that come from the board are ground, 12 volts, signal from transmission, and signal to TCU correct? On the Input Filtering Stage is the 5 volts pseudo ground get fed from the 5 volt stage or the other way? The last thing I need to do it splice the 6 bit plug on the jeeps wiring harness to the 8 pin harness on the tranny. Is this described anywhere? I've had a hard time finding it for some reason. I'm sure it's right in front of me.....

Oh one last thing just to make sure I'm on the right track. In kastein's post he states "1998-2001 AW4s require more work. All the transfer case input gear info from 1990.5-1997 applies" The two transfer cases from the 97 and 98 had the same model number and gear ratio tag on them and bolted right in. Did I miss something and it's not going to work? I just don't want to wreck something due to me missing something stupid.

Thanks for any help you can give.

kikilink333 said:

The 4 wires that come from the board are ground, 12 volts, signal from transmission, and signal to TCU correct?

Click to expand...

Yes. Snip the signal wire from the sensor, feed it to the board. The output from the board goes to the trans computer.

On the Input Filtering Stage is the 5 volts pseudo ground get fed from the 5 volt stage or the other way?

Click to expand...

Yes. :} The 5-volts gets used as a reference in the filtering stage. The filtering stage is basically taking the variable voltage a/c signal and cleaning it up into a nice digital signal. The next stage takes that and every 4th pulse triggers the transistor to pull the output signal down to zero (simulating the reed switch in the older trannies)

The last thing I need to do it splice the 6 bit plug on the jeeps wiring harness to the 8 pin harness on the tranny. Is this described anywhere? I've had a hard time finding it for some reason. I'm sure it's right in front of me

Click to expand...

If you have a 1997 and 1998 shop manual you can compare the pinouts. As I recall doing the 98 with a 90 wiring harness, the wire colors were virtually the same except reversed. For example the green wire with white strip matched up to the white wire with green stripe. You should have a few left over that go to the front speed sensor on the 98 that it's connected.

Or you could just swap in a 1998 trans computer and it's wiring harness. Might get a check engine light, but there have been a few reports that it doesn't. If you do you could maybe leave the 1997 trans computer wired into power and the odb lines so the engine computer doesn't see anything amiss.

Can't quite do either of the things in the last paragraph - putting the 98 computer in would require wiring up the ISS sensor as well, which will require swapping the main chassis harness from the 98 into the 97 or building custom wiring to make it fit. Putting the 98 computer in and giving it the tranny and leaving the 97 there to talk to the ECU will result in a ton of NSS/ISS/OSS/solenoid electrical/solenoid function codes being set.

That kind of trickery only works on renix and obd1 rigs, sadly.

Reportedly you can put the 97 TCU into a 98 and later along with a 97 and earlier trans and everything works great, but this is because the 97 TCU has less speed sensors than the 98 and laters do, so the extra wiring just hangs there causing no problems.

I wasn't sure what the 97 or 98 wiring looked like. On the older stuff I'm familiar with, most of the wiring was separate and just a handful of wires for power tied into the main harness.

Here's what my tired brain was thinking last night about leaving the 97 TCU in place to avoid a check engine light. If the TCU didn't see any pulses from speed sensors and nothing from the NSS, it would think you're just sitting there in park not moving, and report it's happy when polled by the ECU. Not sure if the 98 would notice the solenoids being missing, but that could be cured with a couple of resistors. I've seen a few posts where people converting to a manual did this with success.