I've been mechanically lucky with my 92 YJ until this past weekend. I purchased this gem a few months ago and was told it had a rebuilt tranny (he lied and the number is conveniently disconnected).
Here's what happened, when shifting from 3rd down to 2nd--it was suddenly stuck in multiple gears and immobile. Even the engine locked up. We opened it up and my buddy used a long screw driver to push the mechanism around (can you tell I am NOT a mechanic). It finally started shifting again. I drove it out to his place 25 miles away for body work, and parked it in reverse (the emergency brake doesn't work).
We changed the tranny fluid (it was black and metallic!).
After a few hours of body work, when I attempted to leave, no go into gears again. This time it was stuck in reverse. We attempted the screwdriver trick, but what eventually set it free was driving it in reverse around his acreage. He recommended no longer parking it in reverse, and not shifting to neutral until it's started.
Any ideas? Am I looking at a new transmission? Do you think changing the fluid will help it last awhile?