Hi, I've got a 1989 Jeep Cherokee XJ 4.0 with an automatic transmission. When I stop at traffic lights, the transmission shifts into neutral by itself. When the light turns green and I want to drive off, the engine revs up but doesn't move, and when the engine is revving high, it suddenly shifts into gear, putting a lot of strain on all the transmission components.
Can anyone help with this problem?

 

What's your fluid level at? How's the color and smell of the fluid? When was the filter last changed? How many miles does the jeep have?

 

1st thing is to confirm trans fluid level. Sounds like its low.

 

You could drop the pan to change the filter and check to see if the shift solenoids are good while it's open. I just dropped my pan to change the filter and fluid it wasn't too bad. I had to fight to get the pan off with how bad the oring is so I wouldn't even try to save it just torch where the oring is and pull and heat til it comes off. I let it sit for a day so it wasn't dripping in my face a bunch. If you got a die grinder you can get a white roloc disc it's non abrasive it'll really help get the old gasket that's probably stuck on there off. A green scotchbrite pad and some wd40 also really help and plastic razors. Don't use the gasket that comes with the filter get a good felpro gasket online or from the parts store and you can get a viton o ring set from harbor freight one of them will fit on and fit in snug I used one and it's not leaking and fit fine I believe it was the A110. I was having a hard time getting the pan onto the dipstick from underneath so I took the dipstick tube out it was just one bolt that way you can test and make sure the oring fits and you can put the pan with the gasket on first and tighten all the bolts then what I did is put the dipstick tube back in from the top. I lined everything up and gave it a couple little taps with a deadblow and it seated fine. If you're gonna take off the pan take your time cleaning everything up pan, bolts, mating surfaces etc. I put a quart of Lucas stop slip in it wasn't slipping but it's an old car and it don't hurt. Fill it with about 3 quarts start and let it heat up put it in neutral and check the fluid level and add til it's at full and drive it around then check it again add if needed. Check your fluid level first like the others say and go from there

 

At the tcm connection, inside ( no tools needed) your jeep, probe the solenoid connectors and read resistance. No need to get under and drop the pan