I see that the general consensus is to get the truck to move a little bit to release the bind. I do know that the case does have a syncro gear in them. But I don't like to be moving when shifting, just enough to get it out of 4hi. My old nissan was chain driven and I'd shift in and out of 2 and 4 while cruising down the road with no problems. But gear driven, I wouldn't want to attempt, unless I knew I had a spare to put in.
My hubs are locked in 80% of the time, because I have a couple driveways I frequent, that if I didn't, I'd never get up the driveways. Nothing like going up a steep road, with a tight hairpin turn with loose gravel.
