AW4 issues?

[702XJCruiser]

AW4 quit on me last night when I was heading home from work. I have a receipt for about $1300 worth of work that the previous owner had done to it just before I bought it about 2 years ago. Allegedly rebuilt, shift kit, new torque converter, and tranny cooler.

It's always worked great. Even worked great on my way to work, but after my shift it quit suddenly. Start it up and it'll drive about 50ft then the tranny does nothing as if it's in neutral regardless of the gear.

Always been topped off with DEX3. No leaks, no smells, no sounds.

Start it, she goes 50ft and gives up. Shut it down and wait a few minutes and she'll go another 50ft.

Any ideas?

[cantab27]

whats the oil look like.....

[4.3LXJ]

Does it feel like it has excessive slippage when it moves?

[jeepxj95]

put it all the way down in first and see what happens. maybe the tcu took a crap

[702XJCruiser]

The fluid looks/smells great.

I tried pulling the fuse which should disable the tcu and put it into mechanical mode. Nothing there.

When it does work for the 50ft or so it pulls away normally then it just loses everything at once. Shut it off. Wait a few minutes and she'll go a little more then nothing again.

Very strange. I could understand if it gave out gradually, but she worked like a champ right up till I got to work. Few hours later I get off work I pull it out of the parking lot just fine then she just failed to function completely.

[BlueXJ]

Check wiring to the TPS. If unplugged it will exhibit those same symptoms. Computer is looking for a signal from TPS to allow the torque converter to lock up, thus no signal and tranny goes into survival mode of neutral.

[seu83]

I'm not a real big tranny guy but could it be a clogged filter?

[Mudderoy]

Is it safe to assume it does not work if you put it in 1/2 then shift to 3rd manually?

[Jarlaxle]

Don't suppose you bottomed it out off-road recently? Parking-lot bump in the left-front? Pinched cooler line, maybe?

[jeepxj95]

Is it safe to assume it does not work if you put it in 1/2 then shift to 3rd manually?

i dont think he said. i was suggesting to do that with the fuse in.

[702XJCruiser]

Well I finally had time to dig into the xj last night.

Trans allegedly rebuilt 18 k miles ago according to the $1300 receipt that came with the paperwork when I bought it.

I wanted to test the line pressure but have been unable to track down a 300 psi gauge to do so.

I stay on top of the maintenance always checking things out routinely. The fluid on the dipstick has always appeared good with no indication of foul play right up until the moment I dropped the pan.

1. I pulled tcu fuse. No change.

2. I disconnected the tcu harness. No change.

3. I adjusted throttle cable and shifter cable. No change

4. Drop pan/investigate/new filter/1 gallon fresh dex3

So the journey begins.

1st I hit the drain plug and to my amazement some chocolate shake looking stuff starts pouring out.

I pull the pan and it is the nastiest thing I've ever seen. No metal, but I scraped about an 1/8" layer of hard crap off of the pan. You could see the grit and junk that was probably clogging the filter. The pan itself seemed to have rusted a bit. I scraped/brushed/steel wooled it clean.

http://i887.photobucket.com/albums/ac80/djmell762/xjtalk/002.jpg

http://i887.photobucket.com/albums/ac80/djmell762/xjtalk/003.jpg

Cleaned that up, put it back together with a new filter and a gallon of dex. Started her up and she was shifting in to all gears for a min or 2. Much longer than before. I was amazed and about to pull out for a test run then nothing. Lost all gears again.

Back where it all started.

[Mudderoy]

Well I finally had time to dig into the xj last night.

Trans allegedly rebuilt 18 k miles ago according to the $1300 receipt that came with the paperwork when I bought it.

I wanted to test the line pressure but have been unable to track down a 300 psi gauge to do so.

I stay on top of the maintenance always checking things out routinely. The fluid on the dipstick has always appeared good with no indication of foul play right up until the moment I dropped the pan.

1. I pulled tcu fuse. No change.

2. I disconnected the tcu harness. No change.

3. I adjusted throttle cable and shifter cable. No change

4. Drop pan/investigate/new filter/1 gallon fresh dex3

So the journey begins.

1st I hit the drain plug and to my amazement some chocolate shake looking stuff starts pouring out.

I pull the pan and it is the nastiest thing I've ever seen. No metal, but I scraped about an 1/8" layer of hard crap off of the pan. You could see the grit and junk that was probably clogging the filter. The pan itself seemed to have rusted a bit. I scraped/brushed/steel wooled it clean.

http://i887.photobucket.com/albums/ac80/djmell762/xjtalk/002.jpg

http://i887.photobucket.com/albums/ac80/djmell762/xjtalk/003.jpg

Cleaned that up, put it back together with a new filter and a gallon of dex. Started her up and she was shifting in to all gears for a min or 2. Much longer than before. I was amazed and about to pull out for a test run then nothing. Lost all gears again.

Back where it all started.

I wonder if there is a way to get all the fluid out and replace it. I mean I know they can do that at Jiffy Lube (and other places I'm sure) but how to get there!

Might be time to find a low mileage AW4 at the junk yard, or a donor Jeep.

[uberxj92]

where did the previous owner get the work done? i wanna be sure to never go there. sounds & looks like the system is clogged up .
Mudderoy has a good suggestion by having some place flush it. i go to a local general purpose shop here & have mine done alot.

i was just on the horn with my old man & he told me that you could probably get a decent tranny flush from autozone or the like & do it yourself in the yard. maybe even try running some diesel thru it for about 5 minutes in the driveway. just a thought.

[702XJCruiser]

Last night I did this procedure.

Drop pan, clean filter, add 1 gal fluid. After that it shifted good about 5 mins then clogged up again.

Dropped pan. Removed filter. Flushed out filter. Put back together, 1 gall fluid.
It drove great for 15 mins, thought I got it this time. Then it quit in the driveway. Luckily neighbor was taking out garbage and helped push it in.

Dropped pan again, removed and flushed filter. Still some crud, but not as much and fluid looking cleaner.

The crud in there was spectacular. Giant and copious non-metallic grit particles. It seems like a clutch disintegrated, but she works good till the filter clogs.

If I can't fix I'm gonna throw in the towel and order a new AW4 from quadratec, a 4.6 stroker, dynatrac pro rock 60's etc. Not all at the same time though haha. ;)

[Mudderoy]

Last night I did this procedure.

Drop pan, clean filter, add 1 gal fluid. After that it shifted good about 5 mins then clogged up again.

Dropped pan. Removed filter. Flushed out filter. Put back together, 1 gall fluid.
It drove great for 15 mins, thought I got it this time. Then it quit in the driveway. Luckily neighbor was taking out garbage and helped push it in.

Dropped pan again, removed and flushed filter. Still some crud, but not as much and fluid looking cleaner.

The crud in there was spectacular. Giant and copious non-metallic grit particles. It seems like a clutch disintegrated, but she works good till the filter clogs.

If I can't fix I'm gonna throw in the towel and order a new AW4 from quadratec, a 4.6 stroker, dynatrac pro rock 60's etc. Not all at the same time though haha. ;)

Wow I'm sorta hoping it doesn't work out for ya now! If you can get it to drive 15 minutes I bet you can make it to a place to get all the old fluid out of the torque converter.

Hey you are using DEX/MERC III in there, right? It's starting to sound like either it's the wrong fluid and the clutches are coming apart, or the clutches were crap to begin with.

[Jarlaxle]

Here's an idea...probably need 2 people: Have one person filling it through the dipstick tube. Have the other handling the outflow.

Remove a cooler line, direct it into a large container. Start the engine, and run it to use the internal pump to get as much of the old fluid out as possible.

Maybe have it towed to a trans shop for a flush? NJot much to lose if it doesn't work.

I also had a thought: the cooler is certainly full of glop. Maybe bypass it (temporarily!) and see if it will work more than 15 minutes? If so...well, time to either replace the radiator, or swap to an aftermarket cooler.

[N8N]

Cooler built into radiator? Might be new radiator time. Any evidence of ATF in radiator?

[4.3LXJ]

The cooler thing is a good point. Personally, I think you might be flogging the dog. That is so bad that I don't think you can get it clean without a disassembly. The problem is the crap in the torque converter, which has more oil and crap in it than the rest of the tranny. When they flush them, they hook into it and pump gallons of oil through until they get clean oil. But considering the crap and particularly granular stuff in the pan, I really think this one is not worth saving.

[702XJCruiser]

Yeah with all the crud a clutch must've disintegrated or something. I've been shopping around.

Local rebuilds running $1300

Some Remans Jasper etc: between $2k-$3k

Brand new AW4 from Quadratec $1350 shipped. I think I'm going this route.

Fix it once. Fix it right. Pay once.

[4.3LXJ]

Can't go wrong with brand new

[N8N]

I would still check the radiator or just get a new one since your checkbook is out... Water in the ATF could easily explain what happened to your old one

[702XJCruiser]

I just put in a new CSF 2 core all metal radiator in April and don't lose coolant at any appreciable rate.

It is crazy though after posting yesterday I drove it for 32 mins and it functioned flawlessly lol. I'll continue giving it a shakedown run today. If all goes well I'll take for a power flush to be sure to get as close to 100% of the crap out.

Just freakin crazy how much crap was in there yet in it ran good. Pretty resilient transmission.

[702XJCruiser]

Well update. After having flushed it 3 times at home she's been driving normal like nothing ever happened for the last 2 weeks and about 200 miles.

Pretty crazy how it just bounced back from the dead like that.

[Mudderoy]

Well update. After having flushed it 3 times at home she's been driving normal like nothing ever happened for the last 2 weeks and about 200 miles.

Pretty crazy how it just bounced back from the dead like that.

That's excellent news! Keep a close eye on it though.