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Wont drive forward just reverse!!! HELP!!!

S

Sasquatch707

NAXJA Forum User
Location
Vacaville, CA
NEED HELP! I've had my XJ for two years now and there was always a hesitation to go into gear. But since last year the hesitation got worse and worse, now it will not even engage drive just reverse. 1993 with 180k miles and on a second trans per the previous owner, has an AW4 4x4. I've dropped the trans pan twice now and there was tons of sludge but no metal, the last time wasn't as bad as the first. Fluid doesn't smell burnt but is dirty due to not flushing the system after the first swap. I removed the shift solenoids, cleaned and tested them and they work fine. I have done the shifter cable adjustment a billion times and it hasn't helped. Have tested the TPS and is fine, Idle Air Control Sensor is fine. I need my rig back on the road, please help me!
 
Well here's an update, today I decided to start her up and mess around with afew other things. While shifting into drive the RPMs will slightly climb, I was in neutral and stepped on the gas and through it into drive and it finally creeped into gear but only first. It will not go into any other gears and it doesn't sound good. Could the torque converter be bad?
 
Sounds like the pump isn't generating enough pressure. When you put it in reverse, it boosts the pressure, so it works.

Just to get around the block, put a pint of lacquer thinner in it. That will soften the seals and most likely boost the pressure a bit.
 
Try to get a known working pull, much much less expensive.

Have you tried 2-3 Dex III fluid changes yet?

Sludge means clutch plates may be worn out, but if not, there may be sludge stuck in the valves in the valve body. Add some Trans-x, a pint, run it for 30 minutes, let it set over night, run it for 30 minutes again, then drain it using the AW4 line to the radiator disconnected with the engine running, AW4 in neutral to pump the AW4 dry.

Then refill and drive some if it will engage and drive. See if that frees up the valves. If not, junk it. or save it for a boring week project to rebuild.
 
Last edited:
old_man said:
Sounds like the pump isn't generating enough pressure. When you put it in reverse, it boosts the pressure, so it works.

Just to get around the block, put a pint of lacquer thinner in it. That will soften the seals and most likely boost the pressure a bit.
Click to expand...

Pump? Interesting, I was told when I had the same problem 8 years ago it was worn, dead o'rings in the accumulator pistons in the body of the transmission no longer able to hold pressure (pistons not in the valve body which have been easy to replace with out pulling the AW4).

Laquer thinner or Trans-X will work, I use Trans-X. I think it is safer than lacquer thinner, slower maybe but as likely over do it and loosen trash in big pieces gumming up a valve, but I have no proof of that. I know lacquer thinner is and was the old school method and is still used.

How much would you add?
 
Sasquatch707 said:
NEED HELP! I've had my XJ for two years now and there was always a hesitation to go into gear. But since last year the hesitation got worse and worse, now it will not even engage drive just reverse. 1993 with 180k miles and on a second trans per the previous owner, has an AW4 4x4. I've dropped the trans pan twice now and there was tons of sludge but no metal, the last time wasn't as bad as the first. Fluid doesn't smell burnt but is dirty due to not flushing the system after the first swap. I removed the shift solenoids, cleaned and tested them and they work fine. I have done the shifter cable adjustment a billion times and it hasn't helped. Have tested the TPS and is fine, Idle Air Control Sensor is fine. I need my rig back on the road, please help me!
Click to expand...

The sludge tells me the clutch plates may be toast, which takes a swap or full rebuild. Dropping th pan only gets about 1/3 to 1/4 of the fluid out!!!! Use the cooling hose line to pump all the fluid like I just posted. But if there was that much sludge, twice, I would say the clutch packs are worn out, just for starters.
 
It did sit for many years before I acquired it from a friend, but I'll pick up a pint of Trans-x tomorrow and get things rolling. Might as well try everything I can before I have to take it in. Any other suggestions?
 
No, just the trans-x and drain by the hose/tube method that runs from the AW4 to the radiator, it will get about 6-8 quarts of the total (9-10 quarts?) out all at once. You already cleaned the pan trash out twice. Make sure to have 2-3 pans ready and one person swaping pans while one is ready to sift to Park and cut the engine. Drain it while in neutral IIRC. Pump does not run in park as I recall.

Good luck
 
Ok so before I went to the shop and snagged some Trans-x and fluid to flush the system I decided Id look for the TCM fuse and mine doesn't have one I searched everywhere and no such luck. But I forgot to plug the TCM back in and the jeep would only go into park and 1st gear but no reverse. So am I in need of a TCM or what?
 
Sasquatch707 said:
Ok so before I went to the shop and snagged some Trans-x and fluid to flush the system I decided Id look for the TCM fuse and mine doesn't have one I searched everywhere and no such luck. But I forgot to plug the TCM back in and the jeep would only go into park and 1st gear but no reverse. So am I in need of a TCM or what?
Click to expand...

No, you should have 1 in the 1-2 spot, 3rd in 3, and 4th in OD and Reverse in reverse with the TCM disconnected or its fuse pulled. The guts of the transmission, clutches, are shot, unless you can get Trans-x to clean trash out of the hydraulic valves that control shifting and get it too engage again. Have you tried running in Neutral for 20 minutes to get it good and hot and tried the various gears?.

The tons of sludge you reported is a sign that the clutch packs are toast and that material is now clogging the valve spools and keeping them from operating as well.
 
I was out there messing around with the fuses and had to goto work so I ran out of time. I'll get the trans-x tomorrow and flush the lines and hopefully clear all that gunk out so I can figure out my best next move. I haven't yet to get it running long enough to reach optimal temps, but I will tomorrow. Hopefully I can get it rolling again, might just swap the transmission at this rate.
 
Alright so this morning I flushed the lines after getting the trans fluid nice and hot with running the Trans-x and sure enough that fluid was probably the worst Id ever seen. But was able to get the jeep to 15mph so I'm back to square one... Guess its time for a trans swap after all.
 
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