Classic96XJ

I have a 96' Jeep Cherokee Country Classic, with the AW4 tranny, has 131,000 well maintained miles on it. I am the second owner, the previous owners were meticulous on maintenance. The tranny shifts great on short drives, but on a long trip, and on warm/hot days, it slips in 1st/2nd gear. The engine will rev up to like 3000 plus rpms before the shift kicks in. I checked the fluid, it is red, had it recently serviced 5000 miles ago. The level is good, doesn't smell burnt. It did this on a trip to Vegas, after driving 500 miles and coming to a stop. It did it again up in Northern CA, after driving 300, and it was in the 80's. On short drives, even when it is in the 80's-100 degrees, it shifts ok. I have heard the TPS can have something to do with this? HELP! It drives me nuts! And I am getting ready for a two week long trip where I will be driving inclines in Washington/Oregon! Any ideas on what I should tell the shop guys what to check on it? I don't want them to just will nilly do whatever and then I get screwed!

tech

It kinda sounds like you mite be over heating the trans . Check the trans cooler lines for any kinks or anything like that and may be the trans cooler , you can try flushing the cooler and lines if they look ok . you can try a trans cooler from a grand cherokee they are larger or add in a trans temp gauge to see if it is getting hot .

Classic96XJ

I will try that at the shop I take it to! Thanks for the reply! I hope that is the issue!

BlueRidgeMark

See my sig, #3. That's probably all you have to do.

Classic96XJ

I had a shop flush and refill the tranny back in May, before I drove to Las Vegas, a 1200 roundtrip for me, and I checked the level/color then, looked fine and no burning smell. It seems maybe it is some sensor or electrical issue instead of a mechanical one, but I could be wrong. I am going to have them recheck the tranny and the cooler lines, etc. But also do a TPS test/electrical test on it

EEVEE

if they used the pressure machines it could have damaged it. those machines arent good imo

Classic96XJ

Oh boy, you mean the tranny itself is possibly damaged or just the cooler lines? I would think if they DID do any damage, and this is a very reputable shop, it would be covered under warranty! I hope so! Or they will get my good review on Yelp changed to a not so nice review! HA!

BlueRidgeMark

Depends on whether they did a pressure flush or a fluid replacement. Pressure flush bad, fluid replacement good.

At 130k miles, the trans should not be worn out, and since it's a 1-2 issue, might be a solenoid. They tend to fail when hot. They are easy to replace.

tech

Most transmission machines have a bladder and just do a simple fluid exchange but some do have pumps but it only used to pump the new fluid in , I don't think it would damage the trans . you also could have a trans solenoid going bad once it gets hot .

IJM

First thing I'd do is test the resistance of the solenoids. More info here: https://www.cherokeeforum.com/f2/doe...-legit-195669/

lawsoncl

They usually cut into one of the cooler lines to do the flush. The return just empties into the pan, so they really can't "pressure" anything. Some add a strong detergent, then do the flush, so that could cause issues.

cruiser54

And all these trannies need is a drain and fill every 30,000 miles under normal service and every 15,000 miles under severe service........

Find out WHICH fluid they used. I'm betting they used the Chrysler stuff instead of plain old Dex/Merc.

THAT can cause slipping, along with a misadjusted TV cable, which you can adjust yourself.

awg

dont panic just yet..I have noticed the AW4 (and other trans) can often act up if only a little bit low on fluid, and reading the level is not quite as straight forward as one would wish

therefore, if you just had a trans shop change your fluid, I would suggest that you check your levels very carefully (after reading up on AW4)...and add some fluid anyway!

add 1/2 litre, then another 1/2 if that doesnt fix it...you can drain out any excess in 5mins if the trans becomes overfilled

cruiser54

Checking the level the proper way is indeed a good idea. I would hope that had been done long ago when the symptoms began.

I'm still curious about the type of fluid the shop used since some publications specify the WRONG fluid.

And, it takes about 24 seconds to adjust the TV cable.......

Mortgage Payer

I'm going with the solenoid valves.
They are manufactured to quite close clearances and when hot or dirty, things stop sliding.