tacklebox

OK..... so I have read every friggin thread I can find on this issue. Many 2-3 times. Its seems there are as many possible fixes as there was threads on the problem. Many of which, seemed to fix the issue at first only to have the problem reoccur.


So... I have the TC lock up failure going on. It was not doing it a few weeks ago and I have done many things to the Jeep since, the only one that should have any correlation is TV cable adjustment.


It is intermittent but typically rears its head after 50 or so highway miles. Most of the time an on/off key cycle makes things all better. When it happens it will not hold lock up at highway speeds.


I suspected TPS due to it seemingly getting better after mucking with it. Replaced TPS and was gravy for a couple hundred miles and now its back again. I have readjusted TV cable multiple times to no avail.


Additionally at the same time I became unable to turn off CC by pressing the button. It otherwise works fine just will not turn off. Not positive that the two issues are related but something in my gut seems to think so lol. Weird I know....


So, I have no stored codes, no CEL, no additional issues that may help point toward NSS or brake pedal switch... This leaves me with what? Solenoids and TCM? Would one of those failing not throw a code?

tacklebox

96 4.0 AW4

moparado

When you say it locks up, what do you mean specifically?

By the way i like this thread title!

tacklebox

I mean TC fails to maintain lock up. Maybe that isn't the correct wording. It will lose lock up, RPMS increase a few hundy, if I give er gas RPMS will fall again and TC locks back. Sometimes it will hold other times as soon as I let off the gas a bit it fails again.

jedijeb

I'm not sure how they work on Jeeps (mine is an 85 with 3spd auto so unfamiliar with teh AW4), but I once had a Hyundai that gave very strange TC lockup problems, like would lock going up a steep hill and unlock going down and strange shift point changes ect. Turned out it was a bad alternator! Seemed that without the correct voltages everything just got confused.

Might just be bad grounds somewhere causing intermittent problems.

MWMahoneyJr

How's the fluid? What color? When Trans is slipping after getting warm, people suggest the standard XJ trans flush.

What about this thread: https://www.cherokeeforum.com/f2/tra...r-slip-214658/

tacklebox

Fluid is good, TC isn't slipping just won't stay locked in OD

salad

Have you confirmed that the brake switch isn't kicking it out of lockup?

Dumajones

Doh!!! Salad view..yeah! what Salad said


when it does it..have you pulled the brake pedal up with your foot to see if it locks back up?

tacklebox

Yes, no change.

moparado

Ok, i'm relatively new here but since most of you know what the OPer is talking about can you explain to me what a TransferCase lockup really means?
To me a lock up is a lock up! Dead in the waters, call the hook kinda lock up.

tacklebox

I'm new here too so don't feel bad

TC lock up is what happens when you are at cruising speed you have reached 4 th gear and are giving steady throttle. The TC "locks" allowing RPMs to drop a few hundy. It's kinda the OD for the AW4 in a way although I think technically 4 is geared as "over drive"

When you either tap breaks or apply throttle TC lockup should end/RPMs jump a touch/you are now just in 4th gear.

Probably not the best explanation.

tacklebox

So basically if I am drivin along at say 70 @ 2200rpm and in TC lock then suddenly RPM jumps to 2600 then if I give a lil gas it re-engages and drops back to 2200. Very aggravating, hard on trans and mpg

moparado

You mean TC means Torque Converter and not Transfer Case?
If thats the Case now it makes a little more sense.

Somewhere around 45 mph, the tranny is supposed to shift into over drive which means the rpms will drop significantly.
But in your case it does not shift into overdrive or stays in overdrive below ~45 mph?

I had a similar but not identical situation when my Transfer Case was rebuilt. The tranny wouldn't shift into overdrive.
The shop mis-adjusted the tranny linkage to the point the PCM didn't know if it was in 3rd or 4th gear and threw a spooky CEL code which kept it in 3rd gear no matter the mph.
Re-adjusting the tranny linkage fixed it.

Also double check to see when in reverse gear, the backup lights are on.

tacklebox

Yes I was referring to the converter.... my bad. lol


It will go into OD but SOMETIMES will not maintain it. Usually it takes 50 ish miles at highway speeds before screwing up but not always. This AM I only made it about 7 miles out of town before it acted up, BUT last night I tightened the TV cable a touch playing around. I pulled over, readjusted TV cable AGAIN, cycled the key and drove the remaining 50+ miles into my office without issue. I've been tinkering with the TV cable to gauge its affects on the issue. That and I was already under the hood last night replacing the NEW friggin T-stat I just replaced that decided to stick on the way home last night...


What fun!!


Back up lights are working, although I do question if they are working EVERYTIME. It seems like sometimes when I am trying to check them myself that perhaps they are only coming on as I hit reverse then going off, but every damn time I have someone stand back there they function as they should so....