96 Grand Cherokee 6cyl, auto tranny won't shift

I have replaced the pressure solenoid and the pressure sensor. The Throttle Position cable seems ok too. The tranny will shift manually to 1st and 2nd just fine. When in drive it is always in 3rd. I changed the fluid and filter, the fluid and the bottom of the pan looked pretty clean. I'm hoping it is something simple but I don't know what else to do. Does anyone have some suggestions? I would greatly appreciate some help.

A question to clarify the situation and few things to look at here.

How does it act when you let it shift through the gears by its self?

What kind of fluid did you use??

things to look at.

1 band adjustment

2. throttle cable adjustment

3. Sometimes the heat that these transmissions are subject to will shrink some of the seals. This will affect the shift - usually the 2-3 shift. You will have to back off on the throttle to get it to complete the shift especially when the transmission is not up to operating temperature.

Hope its not the last one


JD

The transmission will not shift at all on it's own. I used Dextron III. The throttle position cable is where it should be according to the Haynes manual. I've heard that the computer controls the shifting in some GCs. I wonder if that could be my problem? The tranny is strong, doesn't slip at all and goes into first and second just fine manually. Every tranny that I've seen go bad slips and makes noises or totally loses a gear. Seems like it should be something simple, but I'm no expert. Could it be a problem with the torque converter? Does anyone know what the symptoms of a bad torque converter are? Does this seem to be a problem that could be solved by adjusting the bands? If so, how do you adjust the bands on these?

well first of all that dextron III is not good for chrysler transmissions. It does funny things and can ruin the trany clutches (so I'm told).

The bands affect the shifts - front band adjusts on the outside of the case on drivers side, rear band is adjusted inside - have to take the pan off.

you need an accurate inche- pound torque wrench to adjust both of them

adjusting the bands may not solve the problem but may help. this should be done as a regular maintenance every two years..

The torque converter won't affect the shifts but it may feel like it is reving too high if the one way clutch goes. may see debree in the pan from that - lots of silver and check it with a magnet. (there is other places it could come fromm too).

There is also the PCM that controls the shift points. It programs its self as you drive on this year i think.. and there are shift solonoids and a few other electronic controls on there too. I'm not in a position to diagnose that part of it...

Other that the fluid, the seals that I mentioned before, and the electronics - the electronics is the one that hits me like the best posibility on this one....

Did you have a dead battery recently? some times that will cause the PCM to forget the program...

thats all I can think of ......Sorry its not more...

JD

I have a similar problem, was there ever a resolution met?

thanks!

Sounds like the govenor is stuck open, this opens a valve that forces the trany into 3rd gear, if the spring(s) are broken it wont return when you slow down, and when you manually shift it into a lower gear you are defeting the govenor. I havent worked on chrysler transemitions but the govenor is usualy behind a plate on the outside of the trany to the back of the main body on the passenger side. sometimes it is a flat plate and some times it is a bell shape.

good luck Leo

if not dextron III then what oil you gays recomend ?

Haven't heard about any error codes - anyone think it could be the TCM (transmission control module). With what you've checked out mechanically, I'd make sure the problem's not electronic...

Sounds like the govenor is stuck open, this opens a valve that forces the trany into 3rd gear, if the spring(s) are broken it wont return when you slow down, and when you manually shift it into a lower gear you are defeting the govenor. I havent worked on chrysler transemitions but the govenor is usualy behind a plate on the outside of the trany to the back of the main body on the passenger side. sometimes it is a flat plate and some times it is a bell shape.

good luck Leo
ended up being the speed output sensor.. cost 120$ to have it replaced at the dealership.. runs like a champ again!

I have replaced the pressure solenoid and the pressure sensor. The Throttle Position cable seems ok too. The tranny will shift manually to 1st and 2nd just fine. When in drive it is always in 3rd. I changed the fluid and filter, the fluid and the bottom of the pan looked pretty clean. I'm hoping it is something simple but I don't know what else to do. Does anyone have some suggestions? I would greatly appreciate some help.

Did you get a fix for this yet?

I had the same kind of problem with my 93 GC Limited. Try checking the TCU (Transmission Control Unit) fuses in the fuse box under the hood. It's also called a module. There is usually two of them, a 10 amp and a 15 amp (both mini fuses). In the '93 if your facing the front of the jeep they are third from left closest row to you. If one of these is blown the transmission will lock up in third gear to protect the tranny from damage. This is designed into the transmission control package at the factory. It's at least worth a look. Good luck and I hope this helps.

I am currenlty having same issue with my 93 jgc lmt 6 cylnder auto, it all started with overdrive flaking out , going on and off and now it doesn't even go on. but I'm still stuck with only 2 gears ( 2nd and 3rd) even when i manually put in Low gear it seems like its only in 2nd not low. I too have replaced the pressure solenoid and the pressure sensor and the governor Plate. still no luck. I think its electrical but that is hard to find. I will look into the fuse suggestion but it will supprise me if it is that easy. I have been running with only 2 gears for about a month now, there are no codes telling were to look at as jeep has been very disappointing as they last suggested that I replace the Transmission , when I ask that can they guarentee that this will fix issue they couldn't, but they would expect me to cover the cost even thought it could not fix issue. A transmission specialist advise me that my transmission is still ok and that it could be electrical, if it is where do I start and how to I reduce the amount of time and cost it could take. any ideas!

Your Probably right about the fix not being in the fuse. It could be blown at this point but I don't think that is the origional problem. It sounds like a short that caused it to work off and on for a while and then it either blew the fuse, burned the wire in two, or damaged the TCU unit. It definitely sounds electrical, but I would still check for metal fragments on the magnetic drain plug just to be safe. I hope you can find it soon and it's not too expensive to fix. Let me know what you find.