i disconnected the huge connector at the ABS computer by the headlight. it has a hex screw holding it on. if your fluid doesn't smell burnt then i bet its electrical... when my tranny starts acting up that fluid smells!
Damn, just remembered something else. The very first day I got the bronco I was playing with the power mirrors and they blew a fuse. This fuse also controls something to do with the speed sensor circuitry.. can't remember exactly but this also wouldn't let me go into OD (or maybe 3rd) and gave harsh shifts. So if that's not the fuse you pulled, check it too.
S H O U L D A G O T T A F O R D!