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Everything you ever wanted to know about the AW4

Not sure if you have discovered this already, but www.bbbind.com/free_tsb.html is a HUGE help when it comes to wiring diagrams. You can just load up the PDFs for any two years of XJ auto trans wiring, print, and compare side by side w/ highlighter in hand.
 
Hey man I have a 1999 jeep cherokee xj which I just recently bought a transmission pump off roc auto due to the old one being defective. The pump looked almost identical to the old one and when I put it in and got the transmission up and went to go turn crankshaft it would not budge. I was wondering if they made different pumps for these models in the 1999 thinking maybe I have the wrong one. If anyone has any input it would be greatly appreciated.
 
Hey man I have a 1999 jeep cherokee xj which I just recently bought a transmission pump off roc auto due to the old one being defective. The pump looked almost identical to the old one and when I put it in and got the transmission up and went to go turn crankshaft it would not budge. I was wondering if they made different pumps for these models in the 1999 thinking maybe I have the wrong one. If anyone has any input it would be greatly appreciated.

What would transmission pump have to do with whether or not crankshaft turned or not? Shouldn't torque converter allow slippage even if transmission were completely frozen in place?
 
Hey man I have a 1999 jeep cherokee xj which I just recently bought a transmission pump off roc auto due to the old one being defective. The pump looked almost identical to the old one and when I put it in and got the transmission up and went to go turn crankshaft it would not budge. I was wondering if they made different pumps for these models in the 1999 thinking maybe I have the wrong one. If anyone has any input it would be greatly appreciated.




If you didn't rotate the t/c until it was fully seated on the drive splines and pump, then you probably just damaged the new pump.
 
Does anyone out there know if the AW4's input shaft is spun up by the TC impeller when the transmission is in Neutral?...in other words, is the input shaft free to be turned by the impeller, or is there some mechanism that I am not aware of that prevents the input shaft from turning while the transmission is in Neutral?

My online research about automatic transmissions in general would seem to indicate that input shaft IS spun up by the TC impeller when the transmission is in Neutral, but a professional experienced mechanic is telling me that the input shaft is to NOT supposed spin up when the transmission is in Neutral.

My symptom is that when I shift (at a standstill) from Reverse into Drive quickly and directly, the shift is very smooth, but if I pause in Neutral at all then the shift is comparatively violent (clunk/lurch). One explanation for this would be that if the input shaft is spinning up in Neutral, then that would allow the input shaft to build up rotational momentum, which would then cause a more violent shift into Drive.
 
Not sure if this was covered but, can you take the output shaft from a 96aw4 and put that into an 87aw4? I have a 96 that the trans is going but have access to a rebuilt 87aw4. So basically going from 21 to 23 splines.

Thanks

STROKER

Yes, but it means tearing the entire trans(both) apart to do so. Where would the benefit be.
 
You can, but bear in mind you'll need to buy and/or fabricate a number of special tools and probably replace more than a few gaskets and seals removed during teardown. That will cut into your savings somewhat.
 
This thread is gold - just read every post in a sitting. THANK YOU ALL!


Need to verify my approach with y'all on something.


I have a '97 XJ 2WD w/ solid body - and a '00 XJ 4WD with a destroyed body.


I'd like to swap the 4WD AW4 etc. to the 2WD body. My approach in regards to the AW4, as I understand it:


'00 AW4 and TCase, TCU, and associated wiring from between these items come from the '00 and go into the '97. It may be a pain to do the loom work, but that's the cleanest approach, yes? Another option would be to go splice-crazy and keep the '97 TCU?


Wondering what the best approach would be (short of finding a donor '97, that is). Money is tighter than labor hours, as this is not a daily driver.
 
This thread is gold - just read every post in a sitting. THANK YOU ALL!


Need to verify my approach with y'all on something.


I have a '97 XJ 2WD w/ solid body - and a '00 XJ 4WD with a destroyed body.


I'd like to swap the 4WD AW4 etc. to the 2WD body. My approach in regards to the AW4, as I understand it:


'00 AW4 and TCase, TCU, and associated wiring from between these items come from the '00 and go into the '97. It may be a pain to do the loom work, but that's the cleanest approach, yes? Another option would be to go splice-crazy and keep the '97 TCU?


Wondering what the best approach would be (short of finding a donor '97, that is). Money is tighter than labor hours, as this is not a daily driver.
Did you thoroughly read post#1?
 
The simplest and cheapest approach is to sell what you have, and buy what need.
 
This thread is gold - just read every post in a sitting. THANK YOU ALL!


Need to verify my approach with y'all on something.


I have a '97 XJ 2WD w/ solid body - and a '00 XJ 4WD with a destroyed body.


I'd like to swap the 4WD AW4 etc. to the 2WD body. My approach in regards to the AW4, as I understand it:


'00 AW4 and TCase, TCU, and associated wiring from between these items come from the '00 and go into the '97. It may be a pain to do the loom work, but that's the cleanest approach, yes? Another option would be to go splice-crazy and keep the '97 TCU?


Wondering what the best approach would be (short of finding a donor '97, that is). Money is tighter than labor hours, as this is not a daily driver.




The 1997 TCU isn't going to work with the 2000 transmission, because the output sensor pulses 4 time/rev, and the 97 TCU is expecting 1 pulse/rev. You'll be in 4th gear by the time you hit 30 mph. There are conflicting reports whether a 97 TCU works in the 98+ without triggering a check engine light, but I haven't seen anyone trying the opposite yet. I'm guessing here, but I would try transplanting the 2000 TCU and see if the 97 engine computer is happy with it. If you try this, please report back whether it worked so we can update the first page of this thread.
 
Agreed. I still have no solid info on 97 TCU+trans in 98+, nor 98+TCU+trans in 97.
 
There are conflicting reports whether a 97 TCU works in the 98+ without triggering a check engine light, but I haven't seen anyone trying the opposite yet. I'm guessing here, but I would try transplanting the 2000 TCU and see if the 97 engine computer is happy with it. If you try this, please report back whether it worked so we can update the first page of this thread.


Thank you, all - I know that the preferred option would be to do a tailcone/sensor swap from a '97 (or earlier?) AW4. Good lord I wish I could, but the pickings are slim, here. It's a budget build for sure, especially since the budget is that of a 17yo high schooler, so that adds a level of difficulty :)



I can certainly try the '00 TCU and hope it doesn't throw a CEL, but I may do (but certainly will prepare for) a slightly different approach.



I was thinking of pulling the entire transmission-related harness wiring from the body of the '00, and working that into the '97. I know that is borderline insane, with the level of effort required, but short of hunting down a tailpiece/sensor that'll work, it may be the only way.


God smiles on drunks and idiots, so here's hoping!
 
Ok folks this is my first post or reply to the site. I am thankful for the information. I will share some information that may be beneficial. You can think whatever you want about what I’ve done, but it was purely out of necessity.
I have successfully installed an 95 transmission in a 98 XJ. Following is as detailed a list of modifications as I can give.
First of all this XJ is a trail rig and is only driven to local trails or trailered to trails that are further.
The trans case had the casting for the ISS but it was not machines out.
I removed the pump and the overdrive hub, packed paper towels into every orifice and any crevice where filings could migrate into.
Pay close attention to how things come apart, take pictures and if possible have an exploded view diagram.
Measuring the outside diameter of the Sensor with a micrometer, I determined that a 19/32 drill bit would get me closest, but finding one in a rural community posed a challenge, so a 37/64 drill bit acquired from the local fastenal was the best I could do in short order and it actually worked out much better. The hole for the mounting bolt was pre-drilled and tapped, but would not have been a big issue if it wasn’t.
With the hole drilled, I test fitted the sensor several times and used the drill bit to take small amounts of material out of the hole for a good fit. This is delicate work with a heavy tool so take your time.
The transfer case adapter is different, so you have to swap those out for the newer style OSS.
Also the newer style counts 4 pulses per revolution the old style only counts 2, so the piece that slips into the output shaft has to be changed. This presented a different issue as the new one is wider than the old one, so I slipped it onto the output shaft and , marked the shaft to show where the snap ring needed to sit.
Again using paper towels to seal off any opening, I used a 4-1/2 angle grinder with a thin cutoff wheel and created the recess for the snap ring.
Installed the 4 pronged counter with the key and installed the snap ring, used carburetor cleaner and compressed air to clean the shaft and housing, re-installed the transfer case adapter, installed the wiring harness from the 98 transmission, installed a new filter, gasket and installed the transmission into the 98 XJ, filled it with fluid and test drive it. The Transmission works flawlessly.
Now before anyone starts hating on the way this was done let me say, if you have never been in a position that you had to have something done and ready to roll by morning, you will never need this type of information. I am a heavy industrial mechanic by trade and I understand the dangers of scoouring a hardened shaft. As for drilling the bing for the ISS, thaw sensor does not leak and I would challenge anyone to show me the detriment of doing this modification.
So in short, can it be done? YES
Should it be done? I would say that depends upon your circumstances.
I greatly appreciate the information provided on this thread and I hope this has been a help to someone else.
 
The old style OSS rotor actually only counts one per revolution - if you look at the back of the rotor you'll see only one lobe has a magnet, the other is there for balancing. Good catch on the difference in thickness and different snapring slot, I had forgotten that detail.

I would certainly agree with your assessment of whether it can/should be done - it's not something I recommend to most people, but if you are up against the wall and on a strict timeline, you play the hand you're dealt, not the one you wish you had. Well done, that's not a set of modifications I'd wish on anyone working under those conditions!
 
Why not swap everything from the 2000 over to the 1997? It should all bolt in just take a lot of pictures and or videos when disassembling. While your at it you use dielectric on everything.
 
You can also replace things like heater core and ac condenser.
 
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