AW4 acting sketchy - time for a new slushbox?

My Jeep almost let me sit along the road today. 88 Pioneer, 210k, bone stock. Driving through some hilly areas, the gears just went away when making a 3-4 shift going uphill. Coasted to a stop at the side of the road. Upon restart, it shifted fine...for about 3 miles then same thing, until I had to slow for a sharp turn. The 1-2 shift took about 6 seconds to fully transition, it held 2nd for about 15 seconds under very mild acceleration then nada. Engine temp never exceeded 210. I managed to nurse it home by putting it in Park, shutting it off, restarting, and then I could go another few miles before losing them again. Aside from this shifting issue - it ran/runs fine.

Once back in the driveway at home...checking the fluid when warm - it looks OVER-filled by about 1/4 inch on the full mark on the stick? Also, at idle in Park, it makes a rhythmic "zizzing" noise - (sounds like bees in a coffee can). Sounds like it's coming from the bell housing from underneath. It "zizzes" for 12 seconds, then quiet for 25 seconds, then the buzzing sound starts back up again. You can set your watch by the frequency. It's not crazy loud, but definitely noticeable, and louder underneath.

I've got a used spare transmission (condition said to be good, not verified however), but am reluctant to install because I'm cheap, no longer have access to an indoor lift, and unsure of Renix compatibility.

I guess my question is....Where is the box I can unplug under the dash (more importantly - what does it look like) to differentiate between mechanical vs. electrical problems in the AW4 or from the description above - do I just need to install transmission "B".?

hey man wats goin on... i got a 96 xj 4.0 witth 226.000 an.. today mines lost overdrive.. on a long ride.. and came back after it cooled down.?? my fluid is there but def needs a change.. otherwise the jeep has plenty tourqe an power.. an runs great.. guess ima start with my fluid and filter..!" gdluckk!!

The Dexron used in the AW4 is good for 30k miles--if it is never overheated. Each time the transmission is overheated the fluid life is cut by 1/2.

When was the fluid last changed? Color? Smell?

There is a yellow power feed to the TCU--under the dash--with an inline fuse. Pull the fuse. However, if your transmission fluid is bad you won't learn much.

Fluid last changed c.2 yrs ago (about 500 miles worth of driving). Color seemed kind of golden/brownish, smelled like transmission fluid, I guess.

Well, I pulled the fuse and took it for a short hop. It slipped in all gears. Looks like I'll be installing the backup transmission after all. Nuts.

freejeep88xj said:

My Jeep almost let me sit along the road today. 88 Pioneer, 210k, bone stock. Driving through some hilly areas, the gears just went away when making a 3-4 shift going uphill. Coasted to a stop at the side of the road. Upon restart, it shifted fine...for about 3 miles then same thing, until I had to slow for a sharp turn. The 1-2 shift took about 6 seconds to fully transition, it held 2nd for about 15 seconds under very mild acceleration then nada. Engine temp never exceeded 210. I managed to nurse it home by putting it in Park, shutting it off, restarting, and then I could go another few miles before losing them again. Aside from this shifting issue - it ran/runs fine.

Once back in the driveway at home...checking the fluid when warm - it looks OVER-filled by about 1/4 inch on the full mark on the stick? Also, at idle in Park, it makes a rhythmic "zizzing" noise - (sounds like bees in a coffee can). Sounds like it's coming from the bell housing from underneath. It "zizzes" for 12 seconds, then quiet for 25 seconds, then the buzzing sound starts back up again. You can set your watch by the frequency. It's not crazy loud, but definitely noticeable, and louder underneath.

I've got a used spare transmission (condition said to be good, not verified however), but am reluctant to install because I'm cheap, no longer have access to an indoor lift, and unsure of Renix compatibility.

I guess my question is....Where is the box I can unplug under the dash (more importantly - what does it look like) to differentiate between mechanical vs. electrical problems in the AW4 or from the description above - do I just need to install transmission "B".?

Click to expand...

Coupla things to do before condemning the trans.
First, as Joe Peters said:

Check the fluid level and condition and the fuse.

Second: Click on the link below and do the procedures outlined in posts 1, 2, and 10.

http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

Dexron transmission fluid--PINK.

Golden/brownish are not options.

I would change the fluid, do a poor man's flush BEFORE pulling the transmission.

Remember--the fluid provides the energy transfer from the engine to the transmission. Bad fluid, poor energy transfer.

Good luck.. Took my jeep for a little ride and she's shifting good.. But I def need to do my filter and fluid ASAP...!! Gd luck!

joe_peters said:

Dexron transmission fluid--PINK.

Golden/brownish are not options.

I would change the fluid, do a poor man's flush BEFORE pulling the transmission.

Remember--the fluid provides the energy transfer from the engine to the transmission. Bad fluid, poor energy transfer.

Click to expand...

I'll give this a shot. I've got 2 gallons of Dex III/Merc. If the weather holds tomorrow, I'll drain, drop the pan, and refill.

cruiser54 said:

Coupla things to do before condemning the trans.
First, as Joe Peters said:

Check the fluid level and condition and the fuse.

Second: Click on the link below and do the procedures outlined in posts 1, 2, and 10.

http://www.cherokeeforum.com/f51/cruiser54s-mostly-renix-tips-153657/

Click to expand...

If the weather holds tomorrow, I'll do these as well. Thx, Cruiser.

You don't HAVE to drop the pan and change the screen if you don't want to. A simple drain and fill will help you determine what the situation is. And, you can always do more of them.

cruiser54 said:

You don't HAVE to drop the pan and change the screen if you don't want to. A simple drain and fill will help you determine what the situation is. And, you can always do more of them.

Click to expand...

Here's what came out...I might have to do more than one fluid swap. Anyone for a transmission cocktail?


Still draining at the moment...will top it off with fresh Dex once it's done.

Yep. A few more.

Wow crazyyyy!!! How many miles is on that fluid round abouts... Curious to see wat mines looks like!!! Gdluck free jeep

96cAmmedxjh.o said:

Wow crazyyyy!!! How many miles is on that fluid round abouts... Curious to see wat mines looks like!!! Gdluck free jeep

Click to expand...

I changed it about 4 years ago or so IIRC it looked like used engine oil - put in about a gallon of DexIII at that time. It's sat pretty much since then. I've only just recently started running it again. So I figure it's an average of 1 gallon @ 500 miles, and the rest about 2 gallons @ 200k mi.

I'll run it for a couple hundred miles or so (assuming it'll run til then) and then do another fluid swap.

FWIW, I ran it for a few miles today after the swap and it seemed to shift just fine. Maybe I didn't kill yet after all.

96cAmmedxjh.o said:

Wow crazyyyy!!! How many miles is on that fluid round abouts... Curious to see wat mines looks like!!! Gdluck free jeep

Click to expand...

You don't KNOW what yours looks like?

How about the transfer case and diff fluids?

freejeep88xj said:

I changed it about 4 years ago or so IIRC it looked like used engine oil - put in about a gallon of DexIII at that time. It's sat pretty much since then. I've only just recently started running it again. So I figure it's an average of 1 gallon @ 500 miles, and the rest about 2 gallons @ 200k mi.

I'll run it for a couple hundred miles or so (assuming it'll run til then) and then do another fluid swap.

FWIW, I ran it for a few miles today after the swap and it seemed to shift just fine. Maybe I didn't kill yet after all.

Click to expand...

You probably won't kill it. Keep doing the changes.

I just got my jeep so.. My trans fluid and diff fluids needs to be done soon like tomorrow to besafe.. I toped of the trans but.. It needs a pan service for sure it's got 226 on it... Otherwise 4x4wrks etc..

No need to drop the pan. Drain and fill. Repeat as needed. Kinda like shampoo bottle instructions.

Ok thanks ....

It takes several cycles to get all the dirty fluid out with the drain, fill, and repeat method. You are only draining half the fluid as the other half is still in the torque converter. This method works for regular service, not once you start having issues.

At this point drop the pan, clean or replace the filter and then flush. Fill with new fluid, disconnect the return line (rear hose into trans) and feed into a bucket. Have someone start Jeep and then add fluid as dirty fluid pumps out. Once the fluid running out looks clean, shut the Jeep off. Reconnect line and top off trans fluid. Done.