94 5.2l issues when going to overdrive and shifting
New member to the site btw, but have been on here several times reading up on plenty of things :-)
Little background on the jeep...
So I picked up a 94 Grand Cherokee (ZJ) 5.2 litre jeep for my wife and it had a bad tranny in it, the bell housing had a crack and the torque converter is stuck to the tranny and won't slide off. Also the crank position sensor was broken.
Well I replaced all that, a new cps, and picked up a tranny from my local pick n pull junk yard. Came with a warranty and I'm still under warranty so I can return it if it is faulty but I want to figure out if its something not too serious that maybe I can swap with the other tranny or pick up a part.
Here's the issues....
After putting in the new cps and the tranny with torq. conv. the jeep ran great, shifted perfectly and everything. Drove it for about a week around town and made a couple trips out of town shifting through all the gears and overdrive. Put about 300-500 miles on it.
Just this last weekend it was me and my wife's 5th year anniversary so we were going to go camping and decided to go to the dunes here in oregon and pull a trailer with a little honda 300 in it, light trailer, I can move it by hand when empty with ease. And driving around town and on the highway can't even tell that their is a trailer behind us :-)
Well when we got about 30 mins from home cruising at about 62mph on cruise control the whole jeep jumped, acted like I hit a small speed bump or rock in the road or something, caught us by surprise. So I took it off cruise control and after we got down to around 40-45 I accelerated back up to 60, and around when overdrive kicks in it started sounding like the gears or front drive line or something was grinding, and then it wouldn't let me speed up anymore... started acting like I was on the breaks or the motor died, so I put it into neutral and the motor was still running so that was not an issue.
long story short....
I had a buddy that was out that way already luckily and he jumped in the jeep with me to see how it was acting and he suggested to turn off overdrive, after doing that the jeep ran fine and shifted great again. So we decided to drive it back home and barrow his truck to use for the weekend and still go camping.
When back in town after stopping at a red light I wasn't able to go... acted like the tranny was slipping, so we figured out that it was not shifting down to 1st, and I had to manually put it into 1st, then 2nd then drive to keep driving, and keep overdrive off.
So..... what is causing it to not to want to shift automatically and for overdrive to not engage properly? Would this be an easy fix? Or is the tranny total crap? Their are no tranny codes showing and the only engine code showing is 12, and that is for if the battery has been disconnected within the last 50 key cycles... (I replaced the battery terminals on it to make sure she had good charging since it was a little corroded :-)...)
Any help is greatly appreciated, if I can avoid swapping out tranny's it would be nice since it was time consuming to pull but not awe full if needed :-)