trans locked?

[strok'd]

1997 f350 4x4 e4od, stuck in forward and reverse? Has anyone had this problem before? I get home from a short drive and the truck won't go into reverse, so I jack it up and throw it in reverse and the wheels roll forward, but only half a rotation, throw it in forward all good, neutral good. Tried to put t case in neutral and i had to jack it up to take pressure off the drive train to get it in neutral. Any ideas?