Re: Bronco II 4x4 not engaging
If it has man. hubs, I would leave them unlocked. Then, put a piece of masking tape on front drive shaft and one on each front axle shaft, wherever you can see them.
Then put it in 4HI and pull forward a bit. Check if the tapes have moved. Should have had driveshaft and one/both axle shafts turn. Move it up again to verify. If front driveshaft didn't turn, then t-case is not engaging front. If its Elec. shift, look down that road.
If all ok so far, engage hubs. Can also jack each side of the front end up, one at a time, and try to spin wheel by hand when eng. is OFF, but left in 4HI. If hub is really locked, should not be able to turn, other than take up play.