1996 Ford Bronco Owner's Manual - Page 198

Touch drive electric shift switch - At extremely low temperatures, it may be necessary to slow down or even stop to shift from two wheel drive to 4x4. - The initial shift from two-wheel drive to 4x4 while the vehicle is moving can cause some momentary clunk and ratcheting sounds. This is the front drivetrain coming up to speed and the automatic locking hubs engaging and is not a cause for concern. - Because of possible damage to powertrain components, never shift from Two-Wheel Drive to 4x4 with the rear wheels slipping. To shift from 4x4 to Two-Wheel Drive: Push the 4x4 button; the 4x4 lamp on the instrument cluster will go out indicating the vehicle is in Two-Wheel Drive. This can be done at any speed. To disengage the automatic locking hubs, operate the vehicle in Two-Wheel Drive in the opposite direction for approximately 10 feet (3 meters) in a straight line. 198