Ford F-250 Super Duty (1999 year). Manual — part 33

Shifting from 2WD (2WD high) to 4x4 HIGH (4WD high)

Rotate the 4WD control to the 4x4
HIGH position at speeds up to 88
km/h (55 mph).
• Do not shift into 4x4 HIGH with

the rear wheels slipping.

Shifting from 4x4 HIGH (4WD high) to 2WD (2WD high)

Rotate the 4WD control to 2WD at
any forward speed. You do not need
to put the gearshift in R (Reverse)
to disengage your front hubs.

To prevent damage, the electronic
shift 4WD system is designed to
allow up to 45 seconds before the
shift command is performed. In the
event that conflicting shift
commands are selected, allow up to
45 seconds for the shift command to
be performed prior to reporting any shift concerns to your dealer.

Shifting between 4x4 HIGH (4WD high) and 4x4 LOW (4WD low)

1. Bring the vehicle to a complete stop.

2. Depress the brake.

3. Place the gearshift in N (Neutral) (automatic transmission) or depress
the clutch (manual transmission).

4X4

HIGH

2WD

4X4

LOW

4X4

HIGH

2WD

4X4

LOW

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4. Move the 4WD control to the 4x4
HIGH or 4x4 LOW position.

Driving off-road with 4WD

Your vehicle is specially equipped for driving on sand, snow, mud and
rough terrain and has operating characteristics that are somewhat
different from conventional vehicles, both on and off the road.

Maintain steering wheel control at all times, especially in rough terrain.
Since sudden changes in terrain can result in abrupt steering wheel
motion, make sure you grip the steering wheel from the outside. Do not
grip the spokes.

Drive cautiously to avoid vehicle damage from concealed objects such as
rocks and stumps.

You should either know the terrain or examine maps of the area before
driving. Map out your route before driving in the area. For more
information on driving off-road, read the “Four Wheeling” supplement in
your owner’s portfolio.

If your vehicle gets stuck

If the vehicle is stuck it may be rocked out by shifting from forward and
reverse gears, stopping between shifts, in a steady pattern. Press lightly
on the accelerator in each gear.

Do not rock the vehicle for more than a few minutes. The
transmission and tires may be damaged or the engine can
overheat.

Do not spin the wheels at over 56 km/h (35 mph). The tires may
fail and injure a passenger or bystander.

2WD

4X4

LOW

4X4

HIGH

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Sand

When driving over sand, try to keep all four wheels on the most solid
area of the trail. Do not reduce the tire pressures but shift to a lower
gear and drive steadily through the terrain. Apply the accelerator slowly
and avoid spinning the wheels.

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.

Once through water, always try the brakes. Wet brakes do not stop the
vehicle as effectively as dry brakes. Drying can be improved by moving
your vehicle slowly while applying light pressure on the brake pedal.

After driving through mud, clean off residue stuck to rotating driveshafts
and tires. Excess mud stuck on tires and rotating driveshafts causes an
imbalance that could damage drive components.

If the transmission, transfer case or front axle are submerged in water,
their fluids should be checked and changed, if necessary.

Water intrusion into the transmission may damage the
transmission.

If the front or rear axle is submerged in water, the axle lubricant should
be replaced.

Driving on hilly or sloping terrain

When driving on a hill, avoid driving crosswise or turning on steep
slopes. You could lose traction and slip sideways. Drive straight up,
straight down or avoid the hill completely. Know the conditions on the
other side of a hill before driving over the crest.

When climbing a steep hill, start in a lower gear rather than downshifting
to a lower gear from a higher gear once the ascent has started. This
reduces strain on the engine and the possibility of stalling.

When descending a steep hill, avoid sudden braking. Shift to a lower gear
when added engine braking is desired.

When speed control is on and you are driving uphill, your vehicle speed
may drop considerably, especially if you are carrying a heavy load.

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If vehicle speed drops more than 16 km/h (10 mph), the speed control
will cancel automatically. Resume speed with accelerator pedal.

If speed control cancels after climbing the hill, reset speed by pressing
and holding the SET ACCEL button to resume speeds over 50 km/h
(30 mph).

Automatic transmissions may shift frequently while driving up steep
grades. Eliminate frequent shifting by shifting out of

(Overdrive) into

a lower gear.

Driving on snow and ice

A 4WD vehicle has advantages over 2WD vehicles in snow and ice but
can skid like any other vehicle.

Avoid sudden applications of power and quick changes of direction on
snow and ice. Apply the accelerator slowly and steadily when starting
from a full stop.

If your vehicle is equipped with a Rear Anti-lock Brake System (RABS),
you should be careful when braking. Front brake lock-up, on any surface,
causes loss of steering control.

If your vehicle is equipped with a Four Wheel Anti-lock Brake System
(ABS), apply the brakes as you normally would. In order to allow the
ABS to operate properly, keep steady pressure on the brake pedal.

When driving on snow or ice with either braking system, allow more
stopping distance and drive slower than usual. Consider using one of the
lower gears.

VEHICLE LOADING

Before loading a vehicle, familiarize yourself with the following terms:
• Base Curb Weight : Weight of the vehicle including any standard

equipment, fluids, lubricants, etc. It does not include passengers or
aftermarket equipment.

• Payload : Combined maximum allowable weight of cargo, passengers

and optional equipment. The payload equals the gross vehicle weight
rating minus base curb weight.

• GVW (Gross Vehicle Weight) : Base curb weight plus payload

weight. The GVW is not a limit or a specification.

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