TFitzPat87

Hi All,

I have a 97 Sport, 4.0, AW4, with 64,000 miles on it. Looks/runs pretty good, and has been pretty well maintained.

When I start it up when all the fluids are cold and go for a drive wherever, it shifts just fine (slips a little into 4th if I'm accelerating really slow). Once it gets warmed up, it starts slipping. It doesn't do it during acceleration much or while cruising at high speed, but when I let off the gas and get back on it at around 35mph it slips pretty good. It's slipped at other gears too but not as bad.

That being said it doesn't do it all the time either, but it happens most at around 35mph when i get back on the gas.

I've checked the fluid and the level and color is good. I plan on dropping the pan and changing the filter just to give it a try.

I'm preparing myself for the worst, but hoping to get some opinions and possible ideas on other things to check myself. Maybe it's something simple (if thats possible) that I just don't know about. I'm no mechanic, but I am handy and have a general idea of things.

Appreciate the feedback!

cruiser54

First off, that "filter" is just a screen. Save yourself the hassle of dropping the pan. It can be a bear.

Couple of things.

I wonder if someone put the wrong fluid into it. Dex/Merc III is all you should use.
If previous owner used ATF+4 or something like that, you could get some slippage.

First I would adjust the throttle valve cable per the following procedure and see what happens. Try that and report back.

https://www.cherokeeforum.com/f2/free-quick-fix-41821/

tjwalker

I agree with Cruiser, if this is a "new-to-you" vehicle, (is it?) I'd get a full exchange of Dex/Merc III compatible fluid in there and see if that helps. If this isn't a new to you vehicle, what fluid are you using? ATF+4 can result in slipping in some (not all) AW4 transmissions.

After checking the above, I would take it to a reputable independent transmission shop and have them take a test drive with you and get their opinion. Might want two of those opinions. They're free.

Any check engine light? If so, you must retrieve codes for guidance and clues.

Good luck and keep us updated!

TFitzPat87

It's pretty new to me. I've only had it since April. I did just do the drain/refill process x3 with Dexron III/Mercon, as I found out that the PO unfortunately put ATF+4 in there as well as a little too much. After that, it was better for a couple weeks, but now it seems like its coming back. I have a few more quarts so I plan on doing it again until I'm out.

I'll do the TV cable adjustment before I take off for work tomorrow. I'm just curious to how that would affect my shifting?

Also, no check engine light. It drives pretty good. It's not perfect but its solid. It is a little sloppy while accelerating while going through the gears though. Like I said in my OP, it's only when I get back on the gas at certain speeds like where it should have down shifted but didn't.

cruiser54

It's a Throttle Valve cable, not a "kickdown" cable.

Fluid pressure in the trans is increased with throttle opening. See where I'm going with this?

The TPS is your "kickdown" input to the TCU.

tjwalker

You might be on the right track. Do the drain/refill process again. Drive it a bit, then do it once more.

As you only get a partial amount to come out with a drain/fill, you'll probably need at least 3 of these to replace the majority of your fluid.

cruiser54

Yes. Drain and fills along with tV cable adjustment.

TFitzPat87

Don't exactly see where you're going with that Cruise. I have a general idea, but I don't know all the technical's.

I ended up sleeping through my alarm clock this morning, so I still haven't done the adjustment. I have done the drain/refill 3 times already, but I mine as well do it again a couple more times since I have the fluid. It's just crazy, cause right after I did the drain/refill before, it was driving real nice! Super smooth, but the shifts were still kind of sloppy. But now that it's gotten cold her in Michigan, it doesn't seem as happy, and just about back to where it was.

I'll do the drain/refill again, as well as the adjustment when I get home tonight. I'll be sure to keep you guys posted.

Appreciate the help!

cruiser54

The TV cable adjustment will increase the fluid pressure in the transmission, possibly eliminating the slipping.

Kalali

You really have to go out of your way to kill an AW4 in only 64K miles. What you might be experiencing is the tranny shifting into overdrive and the torque converter lock up, perhaps too early. Do what was suggested with the TV cable and see if that helps. One other thing you may want to try is gently tap the brake pedal when you experience the "slip" and see if the tranny feels like downshifting. That would be your clue that the torque converter is locking too early. Report back.

TFitzPat87

This is why I say I have a general idea... I thought that's what you were getting at, but didn't know for sure.

Thanks again! I'll keep you guys posted. Not gonna get my hopes up, but if this fixes it, I will be like a new man!

CCKen

Here's the basic diagnosis for slipping:

SLIPS ON 1-2, 2-3 OR 3-4
UP-SHIFT, OR SLIPS OR
SHUDDERS DURING
ACCELERATION

Possible Cause - Correction

Shift cable out of adjustment - Adjust cable
Throttle cable out of adjustment - Adjust cable
Valve body faulty - Repair valve body
Solenoid faulty - Replace solenoid
Transmission faulty - Disassemble and repair transmission

Do you feel shuddering during acceleration?

TFitzPat87

Nope, I don't feel an shuddering/shaking when I'm acceleration.

TFitzPat87

Hey guys,

So I'm back to update you guys on whats happened. I did the drain/fill process 2 more times, so at this point I've done it a total of 5 times in the last month. So the majority of that trans fluid (if not all) should be Dexron III/Mercon.

I then went ahead and did the throttle valve cable adjustment, and it adjusted itself about 1/4 to 1/2 of an inch. Took it for a test drive and it shifts WAY tighter through the gears. I let off the gas a couple times to let it coast down to about 35 mph and got back on the gas and it didn't slip! I don't know if its completely solved the problem but it definitely feels better.

I'll give you guys another update later on next week when I've done my normal driving to and from work to see if it's slipping or not.

I truly appreciate all the help and all the advise! It's nice having a place to go to where a lot of other people have XJ experience and can support others like myself. Again, thanks much, and I'll give you guys another update sometime this coming week!

cruiser54

I'm totally thrilled that your problem seems to be solved.
I only wish you had done ONLY the tV cable adjustment so we could isolate which gave the real/most improvement/cure.