FORD 2003 F-150 v.1 - Manual (Page 156)

Power is supplied to all four wheels
through a transfer case. On 4WD
vehicles, the transfer case allows
you to select 4WD when necessary.
Information on transfer case
operation and shifting procedures
can be found in the Driving
chapter. Information on transfer
case maintenance can be found in the Maintenance and specifications
chapter. You should become thoroughly familiar with this information
before you operate your vehicle.
Normal characteristics
On some 4WD models, 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 cause for concern.
Sand
When driving over sand, try to keep all four wheels on the most solid
area of the trail. Avoid reducing the tire pressures but shift to a lower
gear and drive steadily through the terrain. Apply the accelerator slowly
and avoid spinning the wheels.
If you must reduce the tire pressure for whatever reason in sand, make
sure you re-inflate the tires as soon as possible.
Avoid excessive speed because vehicle momentum can work against you
and cause the vehicle to become stuck to the point that assistance may
be required from another vehicle. Remember, you may be able to back
out the way you came if you proceed with caution.
Mud and water
If you must drive through high
water, drive slowly. Traction or
brake capability may be limited.
When driving through water,
determine the depth; avoid water
higher than the bottom of the hubs
(if possible) and proceed slowly. If
the ignition system gets wet, the
vehicle may stall.
Driving
156