Everything you ever wanted to know about the AW4

Another question: Why is 30-43LE Green Stamp on 4wd XJ's (At least on my '97 4wd w/ NP231)? I've read that is the 2wd model and 40-30LE is the 4wd? Mopar's part# S-4810179 (1994-96 4wd) crosses with 30-43LE.

Page 185 (page 10 scrolling pdf) of Mopar Tranny Reman Program site: http://starparts.chrysler.com/starlibrary/marketing/reman/Trans.pdf

I'm honestly not sure, anyone else got the answer?

I don't really concern myself with what Aisin Warner stamped on the outside, just what's inside and how to make it work and how to tell them apart without trusting the part numbers or tags at all.

o-gauge-steamer said:

Here is how I have my aux transmission cooler plumbed in.

Transmission to fan forced cooler to the radiator to the transmission.

Click to expand...

What is the purpose of the extra cooler in this sequence? Seems it would never cool better than without the aftermarket cooler. If the cooler was after the radiator then the line temps could get lower than the engine coolant temp.

The purpose is to dump the heat prior to getting to the radiator. As I live in the snow... The transmission needs help getting up to it's minimum temperature in the Winter. Hence the routing of the lines. Also, the radiator connection provides a "stabilization" point in the system.

The Stacked Plate Cooler is sheltered from direct air flow (it sits on top of the front skid) and puller fan (650cfm) forced. The fan is on a T-Stat to prevent any chance of over cooling.

Also, keep in mind that the heat exchanger in the radiator is on the "cold" side of things and is not at engine operating temperature.

Any idea what those actual line temps are before and after each of the two exchangers? I guess my only thought is I know how efficient liquids are at transferring heat...so I can't help but wonder if the transmission fluid leaving the radiator is at the same temp it would be with or without the "pre-cooler". It also seems to me that regardless of the temp of the fluid coming out of the pre-cooler, the exchanger in the radiator would either heat it up or cool it down, depending. What am I missing? Given the current setup I'm not sure how it is even possible to over cool anything, since the trans fluid returning to the transmission should always be really close to the coolant temp on the cold side of the radiator.

You do What to downshift?

OK, this is going to sound weird, but...

As I climb steep grades here Constantly, I spend some effort trying to be in the right gear, especially if I get a slow poke in front of me.

I noted that often the AW4 will upshift and lug a bit too much in a higher gear if I lift, and getting it back down it might jump lower than I want only to upshift again.

Lately while climbing a grade if I want to drop one gear without stepping down on the gas I tap the brake - yea weird but it works great. Depending on where your foot is (telling the AW4 when to downshift) it sometimes helps me to climb the long grades with a lot less trying to find the sweet spot.

So forgive me I am new to the world of xj. I currently acquired a 1994 with a bad tranny. I swapped in a 1998. Everything looked the same except the little piece at the tailhousing. So i cut the wiring and spliced it in figured done. But then when I drove the vehicle it wont shift. Asking around I got turned onto this site and this thread. Now I see the 1998 aw4 has a differnt tailhousing. So unfortuantely i tossed the piece out of the original 1994 tranny along with the pigtail. I saw on this thread that there was a digram on how to make it work but it doesn't seem to exist anymore. I may have missed it in all the pages but I was starting to get the deer in the head light look. On the 1998 tranny there is a connector towards the bellhousing that wasn't on the 1994. On the 1994 there is a pigtail that doesn't plug into anything on the 1998 (goes towards the rear of the tranny). I spliced the long piece in the tailhousing connector into the short piece connector on the 1998. I just swapped the little thing on the passenger side with the one from the 1994 (gear shift indicator?). At this point I'm lost. My rockcrawler is a 1994 yj with a chevy350, th400 and altlas 3.8. Next to no wiring...yippy! I have knowledge on how to fab and bend tube and weld but all this electric solenoid stuff has what little bit of hair I have left wanting to just jump ship like the rest.

Another not. I used the 1994 harness and just cut and spliced the two wires that go to the speed output sensor. I plugged in the shift solenoids from the 1994 harness to the 1998. I assume (we all know the problems with assumptions) that I need to do something with the speed output? Like I said before I tossed the 1998 harness and the speed sensor from the 1994. There was a picture a few pages back and that was wxactly what my 1994 looked like. AN extra pigtail just hanging there. the 1998 has a blue connector up by the bellhousing. on the 1994 it had a blot hole in the same place but nothing there.

You will unfortunately need to get a 1994 output speed sensor, tailhousing, and output speed sensor rotor (it clips onto the output shaft inside the tailhousing) - or wire up the circuit I described, designed by clawson, in the first post. The latter is probably a better idea, it will cost less and not require dropping the transfer case and pulling the transmission adapter housing apart. Got any local buddies who are good with soldering irons and wiring?

If you decide to replace parts instead of wiring up the circuit, any 4wd aw4 from a 91 through a 97 will have the parts you need. Probably can find a smoked donor that needs a rebuild for free or almost free.

The reason it isn't shifting is that the computer is expecting a switch closure on the output sensor wires every shaft rotation, and instead it is getting 4 voltage pulses per rotation.

The neutral safety switch is the bit you changed out on the passenger side - I think you have that one correct. Make sure it is adjusted correctly, I forget the procedure but as long as your reverse lights work and it will start in both park and neutral you should be close.

kastein said:

You will unfortunately need to get a 1994 output speed sensor, tailhousing, and output speed sensor rotor (it clips onto the output shaft inside the tailhousing) - or wire up the circuit I described, designed by clawson, in the first post. The latter is probably a better idea, it will cost less and not require dropping the transfer case and pulling the transmission adapter housing apart. Got any local buddies who are good with soldering irons and wiring?

If you decide to replace parts instead of wiring up the circuit, any 4wd aw4 from a 91 through a 97 will have the parts you need. Probably can find a smoked donor that needs a rebuild for free or almost free.

The reason it isn't shifting is that the computer is expecting a switch closure on the output sensor wires every shaft rotation, and instead it is getting 4 voltage pulses per rotation.

The neutral safety switch is the bit you changed out on the passenger side - I think you have that one correct. Make sure it is adjusted correctly, I forget the procedure but as long as your reverse lights work and it will start in both park and neutral you should be close.

Click to expand...

+1. I have little to add, other than if the solenoids are getting power but the TCU isn't getting the proper speed signal, then the trans will be stuck in first gear. If the solenoids are not hooked up properly then you will be stuck in 4th.

Note: Never throw any parts away until everything else works.

lol. I know I broke the cardinal rule and tossed the little elec piece, it just happened to be trash day when I wrapped up. DUMB DUMB DUMB. I still have the old tranny. I tried the link for the diagram on the first page but get a 404 error. If anyone has it please let me know. I can handle soldering and wiring but its real low on my stuff I call good times.

kastein said:

The reason it isn't shifting is that the computer is expecting a switch closure on the output sensor wires every shaft rotation, and instead it is getting 4 voltage pulses per rotation.

Click to expand...

I found this out the hard way too when I stuck a 99 AW4 into an 89 to replace the manual. I'm curious that you say it's not shifting at all though In my case, I found 99 tranny would trigger the 89 TCU just 4x too fast. It would shift about 1000 rpm and I was in 4th gear by the time I hit 20mph.

The circuit I stuck together way back in 2005 is still working great in the 89 MJ. Not bad since almost all the parts came out of my scrap parts bin and winging it. Holler if you want the pdf of the diagram. I think I still have it somewhere.

I'm not sure how I screwed up your username and got clawson instead of lawsoncl, but glad you saw this!

lawsoncl said:

I found this out the hard way too when I stuck a 99 AW4 into an 89 to replace the manual. I'm curious that you say it's not shifting at all though In my case, I found 99 tranny would trigger the 89 TCU just 4x too fast. It would shift about 1000 rpm and I was in 4th gear by the time I hit 20mph.

The circuit I stuck together way back in 2005 is still working great in the 89 MJ. Not bad since almost all the parts came out of my scrap parts bin and winging it. Holler if you want the pdf of the diagram. I think I still have it somewhere.

Click to expand...

I sure would. I sent you a pm. It just acts like its stuck in low gear. I know the kickdown cable is frayed but I disconnected it as I read that it may be causing the problem and it had no effect. I do know that when I was trying to pull of the plug of the speed sensor the wires pulled out. Maybe I have them in the wrong side?

kastein said:

I'm not sure how I screwed up your username and got clawson instead of lawsoncl, but glad you saw this!

Click to expand...

I'm actually still subbed to this thread, so saw the email.

BigBluetrg said:

I sure would. I sent you a pm. It just acts like its stuck in low gear. I know the kickdown cable is frayed but I disconnected it as I read that it may be causing the problem and it had no effect. I do know that when I was trying to pull of the plug of the speed sensor the wires pulled out. Maybe I have them in the wrong side?

Click to expand...

Polarity doesn't matter on the speed sensor wires, so that's probably not it. If you stick a voltmeter across the sensor with the drivershaft spinning (or xfer case i nneutral and tranny in gear) you should see an erratic looking voltage.

Having the throttle cable disconnected entirely might prevent it from shifting. It's really not a kickdown cable as the computer controls when to shift, but rather it controls the hydraulic pressure and the shift firmness. Way out of whack or totally disconnected results in sluggish or no shifting at all.

oh well this one is frayed so ill order a new one and change it out and see if that helps. But i'll still need that diagram if you still have it. Thanks for your help.

Wish I had one to give you, I already gave my extra one away to someone else in your position!

I'd hit a junkyard, though it is a pain to get out, gotta drop the pan to get the transmission end disconnected. The part number for a 94 is 5207 7578 from the dealer, there are a lot of online places that can probably save you a bunch of cash, just do not use factorychryslerparts for any reason. I've had great luck with factorydiscountparts.com under their previous ownership and will probably give them a try now that they've reopened again. Seems they want $25 for the part.

kastein said:

Wish I had one to give you, I already gave my extra one away to someone else in your position!

I'd hit a junkyard, though it is a pain to get out, gotta drop the pan to get the transmission end disconnected. The part number for a 94 is 5207 7578 from the dealer, there are a lot of online places that can probably save you a bunch of cash, just do not use factorychryslerparts for any reason. I've had great luck with factorydiscountparts.com under their previous ownership and will probably give them a try now that they've reopened again. Seems they want $25 for the part.

Click to expand...

What exactly is the cable called? I have tried a search for kickdown cable and transmission line pressure cable. Looking at the cable it loos like a bicycle brake cable. I could just cut the old one out and run a new cable. I can get the crimps from a local hardware store.

it's got a goofy seal/bracket setup on the transmission end. It's called a throttle valve cable apparently, or something like that, just search for 5207 7578 in the "search by part number" section on the right side of the screen on factorydiscountparts with the brand set to jeep and it'll pop right up.