Explorer Stalls/Transmission Problem

[paudemge]

My sons 1992 Ford Explorer with over 100k miles looks like it has something wrong with the transmission.
He can drive it around our neighbor hood with no problems, however, if he goes a little further it may start to vibrate and then may die.
And then once it has died he can start it ok, but as soon as he puts it in gear it will die. After a few hours it will usually be ok again.
Some times it won't die will driving , but will still have the problems stalling after he stops.
Seems to maybe related to how fast he goes, i'm sure he doesn't exceed about 30mph in the neighborhood, but i'm pretty sure that even if he goes a short distance outside the neighborhood, he probably goes about 35-45mph. Also the longer he drives the longer it seems you have to let it wait before you can drive it again. I thought it might be a problem with OD, but he says he doesn't even use OD.
Any insight will be helpfull, thanks.