Yet another AW4 Issue.

I searched, found nothing. I have an 89 with the AW4. Jeep has around 240k miles. When I got the Jeep the PO has stated that the Jeep just stopped driving one day and left him stranded on the side of the road. Said it the engine would only rev up when in gear, but no movement. So before spending too much money on a tranny, I figured I would replace the change fluid and the torque converter first. I drained the fluid, it was burgandy color, and smelled like ATF, with a bit of a scent of burnt(very little). I among many of people these days, installed the tc on the flywheel first, then slid the transmission up as I turned the output shaft on the tcase until it slid all the way forward. Hooked the lines back up, cranked her up, then commenced to filling it up with new ATF. Put it in gear and it moved. Shifts 1-4 fine. Except for when its first started up, tends to slowly move until the fluid gets pumping. I have little reverse. Reverse only works when at idle. If I give it any gas, it feels like a slip out of gear, and as you rev, you feel a vibration(TC spinning). I have had numerous anwsers from a pump to a sprag thats went bad. I just want it working again. Any ideas on where to start? Should I drop the tranny, inspect for damage, replace the pump, then put the TC on the right way? or Attempt to locate a lower mileage AW-4 from the JY where the cost $80.

Replace it.

GO to your nearest junk yard, and swap it.. if you are lucky then you can get a AW4/t-case combo and swap the whole thing.

Yeah, swap it.

as far as compatibility....I will need a 87-90 if I want to use my t-case. For newer, Swap both, which gives me a 23 spline output for the t-case. Im fine up to a 99? I think one of those years, the Trans got converted from being controlled by the tcm to the pcm. Can anyone confirm?

You're semi correct. The TCU has always controlled the transmission on the 4.0L XJ. You want an AW-4 from anything up to a 97. 98 and later they changed the output speed sensor from 1 pulse per revolution reed switch pickup to 4 pulses per revolution coil/reluctance pickup. You may need to cut and splice some wires to put the right connectors on the later years (91-95, 96, 97) but they will be the same electrically and mechanically.

If you were a little closer I would give you a 21 spline AW-4 I have in my storage unit, but NC is a bit of a drive. There is a guy giving one away in northern NJ, check the NAC classifieds subforum, I'm not sure if he still has it.

kastein said:

You're semi correct. The TCU has always controlled the transmission on the 4.0L XJ. You want an AW-4 from anything up to a 97. 98 and later they changed the output speed sensor from 1 pulse per revolution reed switch pickup to 4 pulses per revolution coil/reluctance pickup. You may need to cut and splice some wires to put the right connectors on the later years (91-95, 96, 97) but they will be the same electrically and mechanically.

If you were a little closer I would give you a 21 spline AW-4 I have in my storage unit, but NC is a bit of a drive. There is a guy giving one away in northern NJ, check the NAC classifieds subforum, I'm not sure if he still has it.

Click to expand...

Sweet, thank you! I sent a PM to the guy, hopefully he'll still have it. Any reason why you would give yours away free? My sister lives in Lowell, and shes been bugging for me to come see her for the past 4 years.

I got it for free from another guy I know on here, all it needs is a front pump seal (his bellhousing bolts backed out and it flopped down a bit and blew the seal) - then I realized I didn't really want to swap in all 21 spline stuff because I want to avoid parts availability issues, 21 spline hardware is getting rare up here in the rust belt. I actually have the matching transfer case too (though I paid for that.) I can drop it by lowell if I remember to get it out of my storage unit at some point, and also I'm planning a trip to southeast PA this weekend though driving from NC to PA for just a transmission would be a waste of time IMO.

I dont think she has the room. Shes in a studio apartment. haha. PM sent.

Got the tranny from the 95 out. Two problems I see so far. Speedo sensor is electical and not mechanical. Front axle will not longer be controlled by t-case, so no more 4wd light when engaged. Im not worried about the 4wd light no longer working, Im certain I can figure out a way to wire in a switch on the t-case to flip the little light on. If not, i can look down and see the lever pulled. My biggest concern is the speedo. Can I simply swap the tailshaft's off the t-case's since that's where the speedo lives?

I am pretty sure you can just swap the speedo takeoff assembly right into the new transfer case. Could be wrong though :dunno: give it a try and see if it fits. Also make sure you index the thing properly and actually get the speedo gear teeth engaged else you'll be buying a new gear pretty soon.