LB,
When shifting the rear from high to low you need to have the truck under load (like when pulling a hill and loosing speed). While under load put the switch in low rear, then let off of the gas, then wait until you hear the rear transfer to low and then mash back down on the gas. You can't easily shift from high to low while rolling along on a flat road, if you need to down shift under these conditions use the transmission.
Mike B
