NewJerseyXJ609

Hey guys, been a while since ive been here. Mostly because my jeep rarely breaks . lol. Anyways, as of a few days ago the truck wont shift out of first. Ill drive it and park it. Come out start it again and it wont shift. It will be screaming at 25 mph. Its a 95 cherokee with the l6 automatic. Ive changed the speed sensor on the transfer case and thats it so far. After changing that i thought i was home free. But after 25 mins of shifting fine, once again it stopped shifting. There is plenty of fluid in the trans. And i have the x-fer case in 2H. No check engine light. stumped. Hopefully you fine folks can give me hand.

NewJerseyXJ609

This truck is my daily right now and i need it to get to work. so i could use all the help i get. But with it sitting at 8k rpm at 25mph... thats a no go. lol.

Lostfisher1

So it worked fine for 25 min? check ur wireing.

NewJerseyXJ609

yes its wierd. I can start it and drive for a bit with normal shifting. Then after either stopping at a stop sign or shutting the truck off it wont shift. When i manually move the shifter down it will. When you say check wiring. Which wires? would changing the trans filter fix this issue? I didnt see any bubbles on the trans dipstick indicating a clog

macgyver35

My guess, based on your "25 minutes" thing, is that you may have crap fluid that barely does the job when cold (at least what the trans would consider "cold") and once it gets hot you loose functionality. You say you have full fluid. Make sure its not overfull. That's just as bad if not worse than being low. Also, your fluid should by bright to dark red. If it's brown, gray, or black, or smells burnt, you need to change it. Do you know when, if ever, the fluid has been changed? Not just the three quarts at a filter change, but a full change? If you have bad fluid, use the search to look for the "forward flush" technique that uses that trans's own pump to perform a flush/change. It works well, and has less of a chance of blowing out seals like a typical auto shop's reverse flush method. You can do it yourself in your garage with a helper for just the cost of new fluid, a 5 gallon bucket, and a 4 foot piece of garden hose.

If your fluid appears good and you can ascertain that you don't have a clogged filter...

When it starts doing the no shift thing, manually put the shift lever in the 1/2 position and take off normally. When you get to around 2800 RPMs, try moving the lever to 3. If it shifts then, take it up to 2800 again and move the shifter to D. I'm suggesting 2800 RPM because that would be a point just above where it would normally shift under a typical load on flat pavement.

If you find that this trick works consistently, you can start checking other things. Test TPS, and check all wiring associated with it. The trans uses signal from the TPS to help determine shift points. Check you kickdown cable and make sure there's no binding or anything else unusual.

If you still have an issue once you've gone over the stuff you can easily change, inspect, and test, it's time for more extensive troubleshooting, and others here may be able to help you more.

NewJerseyXJ609

thanks so much mac. Im going to test everything you suggested. I have NO idea when the fluid was last changed. possibly never. hehe. I got the truck with 182k and it has 212k now. It had a bad tps when i got it. So that has been changed but a while back. Ill test that out. And as far as the fluid goes... ive been told by many people NOT to change the fluid bc when you do in the old AW4's they tend to slip with new fluid. Thats why i havent changed it. Is this just a myth?

macgyver35

I think you'll find as much debate on that as you would on Ford vs. Chevy. Some say never to change it unless it's brown or black. Others will tell you that regular fluid changes will help that AW4 run forever. I fall in with the latter group. Never changing your trans fluid makes about as much sense to me as never changing your motor oil. I've changed mine using the forward flush method I mentioned and noticed an improvement in performance. No ill effects so far after 4 months. Just be sure to get Dextron/Mercon III.

NewJerseyXJ609

Just wanted to give you guys an update. I changed the speed sensor and for a day it kept acting up. And now for 2 months I've had no problem. Don't you love the jeep gremlins. Lol

4.slow95

TCM. Transmission control module. Mine did this exact same thing. I would work sometimes and then sometimes not. Changed it with one from the junk yard for $11 and drove it for a year before I sold it with no issue. Hope that helps

NewJerseyXJ609

Thank you! If it starts to act up again this is what I will do.