We have a '93 grand Cherokee. We bought it used with 150k on it. Other than regular maintaince we have had no problems. Saturday morning we got in to go to my sons baseball game and it wouldn't shift up or down unless my husband shifted manually. It wouldn't shift into overdrive at all. We took it slow to the game as we didn't have time to switch vehicles. After the games we got in and it shifted fine. It was 42 degrees outside that morning and 85the after the games. I called my mechanic and he changed the fluid an put new solenoids on the two highest gears as they were worn, new filter and fluid. He drove it and it was doing great. Again this morning it was chilly out and it wouldn't shift again. Any ideas before I have to spend the money to rebuild the whole thing? Any help would be much appreciated!!!!

 

Why do people insist on throwing parts at transmissions who don't know what they are doing.
Anyway, someone needs to check and see if there are any codes.
My guess is that it went into limp mode. Moat common are governor pressure solenoid and sensor.
There is only one solenoid that affects gear change and that is fourth gear.
Double check which solenoids he changed, maybe he changed 4th and lockup.
If the governor solenoid is bad though there should be fault codes. This needs to be checked first so you can avoid throwing more money at it that doesn't fix it.
Also let us know what he actually changed. But that would be my bet.

 

Do you happen to know which trans the jeep has. I am going to assume its a 4.0L with a 42RE. Did you check for any codes/DTC's?

When you say you shifted it manually, which gears did you have? Did it seem like it was taking off in 3rd and by manually shifting into 1st you got 2nd gear? The 42RE shifts hydraulically 1-3 but it also relies on a electronic governor solenoid and pressure sensor. If the gov solenoid or pressure sensor fails it goes into "limp" mode which gives you 3rd gear starts, but 2nd can be obtained by manually shifting to 1st. If I was to make a guess, I would say the governor solenoid and pressure sensor/transducer would be more likely the failure over anything else. Since you did mention this could be temperature related, its possible to have a sticking valve in the valve body too.