Ford 1996 Bronco Manual page 199

For example:
If you were driving the vehicle forward in
4x4, the automatic locking hubs will
disengage the next time the vehicle is driven
in reverse in Two-Wheel Drive for
approximately 10 feet (3 meters) in a straight
line.
If you were driving the vehicle in reverse in
4x4, the automatic locking hubs will
disengage the next time the vehicle is driven
forward in Two-Wheel Drive for
approximately 10 feet (3 meters) in a straight
line.
Operating in two-wheel drive mode with the
hubs locked increases fuel consumption, noise,
vibration, and wear. For prolonged two-wheel
drive operation on dry pavement, disengagement
of the automatic locking hubs, which is not
required for two-wheel drive operation, stops all
movement of front-wheel drive components
while operating in two-wheel drive.
To shift from 4x4 to 4x4 LOW RANGE:
Stop the vehicle and place the automatic
transmission in NEUTRAL or depress the clutch
on vehicles with a manual transmission. Push
the LOW RANGE button on the instrument
panel to shift the transfer case from 4x4 to 4x4
LOW RANGE. Both the 4x4 and LOW RANGE
lights are now lit.
NOTE: The vehicle must already be in 4x4
before pushing the Low Range Button.
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