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aw4 acting up

bcmaxx

bcmaxx

NAXJA Forum User
Location
The West Kootenays,B.C. Canada
91 xj.4.0 4dr auto

Did some snow wheeling today, went good she pulled great all day, on my way home I had to stop for a light,went to gas it in drive and it was as if it was stuck in drive, wouldnt downshift. I dropped her into first and manually upshifted fine, next stoplight same thing. (kinda like being stuck in the mud in 4hi and powering out) . I got home checked the fluid, level and condition is great and smells good. Immediately hop back in now its fine. Sticky shift solenoid? I'm going to run seafoam through it and replace the fluid see if it helps, just seeing if anyone else has had this problem. My 89 has been subjected to 4 yrs of hard use and has not acted up once ever.
 
Any check engine light? If so, pull codes.

Keep in mind that the throttle position sensor is directly associated with transmission performance.

If you're going to use a Seafoam product in your transmission, be sure that it's TRANS-TUNE, which is the Seafoam product designed specifically for that purpose.
 
I think it might have been in limp mode. 2nd gear only. When you shut it off and then restarted it went back to normal mode.

mine did that before when I was doing drifts in an ice covered lot
 
Did it again immediately this morning, Stopped for a coffee and back to normal The torque is locking up in 3 and 4th , in 1-2 mode it doesn't lock up so If I manually shift up and down it'll work for me, Definetely will be trying trans-tune we stock it at work. Letcha know the outcome.
A few other things I may try is unplugging the tcm and trying it, And id all else fails wire in a set of switches to control the trans and lockup
 
200K XJ said:
I'm currently experiencing this problem with my 95xj (4.0l auto). What ever became of your problem? Please let me know what you found!
Click to expand...

Its been a while, so send him a PM--left click on the user name, and let him know you want to find out how his situation worked out.
 
seafoamed and replaced the fluid, never acted up again, thinking just a sticky solenoid. Never got it to do it again.
 
I'm having this issue in my 96 with the AW4. I did a drain and fill the other day on the tranny pan (fourth time I've done it over the last 6 months. Fluid level is good and fluid itself is looking decent. Also to note, I just lubed the driveshaft to eliminate the notorious clunking issue. Same issue as the OP, won't downshift to 1st, but 1st works fine and shifts up fine when I drop the selector down to 1/2. I'm a bit leery about running Trans-Tune since I don't think this thing has had a tranny flush in a very long time, hence the long progression of changing the pan fluid.
 
Ok, fluid looks good and should be reasonably fresh.

Have you tested the TPS to see if it is in spec or needs replacing?

Have you adjusted the throttle pressure cable?

Have you measured the resistance of the solenoids?
 
joe_peters said:
Ok, fluid looks good and should be reasonably fresh.

Have you tested the TPS to see if it is in spec or needs replacing?

Have you adjusted the throttle pressure cable?

Have you measured the resistance of the solenoids?
Click to expand...

I have not tested the TPS, how would one determine if it is in spec or not?

The throttle cable seems to be ok, checked it not that long ago when I was researching the clunking issue.

Not sure how to measure the resistance of the solenoids, is something an amateur like myself can do?
 
Well this weekend it just started acting normal again, ad then yesterday it acted up again. There is no inbetween, it either works normally or stays in OD. I picked up some Trans Tune and put in half the bottle. I'm going to do the throttle cable adjustment tomorrow as it feels like there's some play, but I'm unable to see how the trans tune worked so far right now. I had to leave the XJ with my parents since my mother's car just threw the transmission code of death. I'm gonna take it for a spin tomorrow and see what happens... I'm assuming at this point that it is a sticking valve.
 
Unplug the TCU--drive it shifting manually. You will get 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, park. If that is what you get, then you can rule out mechanical or hydraulic problems.

If the issue is electric--TCU, TCU fuse, TPS, solenoids, NSS (very remote), or the wiring harness/connectors.
 
Well I finally got my XJ back from my parents today, and it's still acting up. I have finally found some kind of a pattern to it though. It occurs whenever the vehicle comes up to normal operating temp. Now, this started when I did the last drain and fill. I know the fluid level is a tad high. Can excess fluid cause this to occur? I haven't had a chance to un-plug the TCU yet since I just got it back, but like I said, this only starts to occur once the Jeep warms up completely...
 
Your better off running low than overfull.
 
im wondering if the overfill symptom is a result of something going on inside. last week i swapped out my 89 aw4 for an 88 aw4 and everything was working great. i had the fluid level just right. yesterday the trans started skipping 2nd after it warmed up, meaning when going from a stop it would shift from 1st to third or even overdrive. seems to not do this if the gear selecter is in 3 instead of od. i tried readjusting the tps with no luck. after warming it up again and checking fluid level, it was high. id say about a quart as it shows fluid almost all the way up to the bend in the dip stick. but when i did the install i made sure to add fluid slowly to not overfill it. why it is showing overfull now is kind of weird. could there be a relation to the shifting problems?
 
2stix said:
im wondering if the overfill symptom is a result of something going on inside. last week i swapped out my 89 aw4 for an 88 aw4 and everything was working great. i had the fluid level just right. yesterday the trans started skipping 2nd after it warmed up, meaning when going from a stop it would shift from 1st to third or even overdrive. seems to not do this if the gear selecter is in 3 instead of od. i tried readjusting the tps with no luck. after warming it up again and checking fluid level, it was high. id say about a quart as it shows fluid almost all the way up to the bend in the dip stick. but when i did the install i made sure to add fluid slowly to not overfill it. why it is showing overfull now is kind of weird. could there be a relation to the shifting problems?
Click to expand...

oops, i meant i readjusted the throttle position cable. i really need to proof read more.
 
Sorry to bring this up again but I guess its better than doing a new thread. Has anyone in this thread actually found out what the problem was? My 88 4.0 aw4 is acting up also, it is acting like it is staying in od or 3rd and not dropping down when I slow down. Also when I manually shift it it does not shift to second at all even when I hit the red line. I have replaced the tps and done the throttle cable adj. fix. All this started after a mnt. run and snapped an axle and had to be drug back with the wheel chained in position. Please let me know Thanks Y'all
 
Have you tried a few transfusions with new Dex III fluid yet?

It is less confusing if you start a new thread, after reading all the old AW4 threads first.
 
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