Ford Super Duty (2018 year). Manual — part 55

Driving on Snow and Ice

WARNING

If you are driving in slippery
conditions that require tire chains or
cables, then it is critical that you drive

cautiously. Keep speeds down, allow for
longer stopping distances and avoid
aggressive steering to reduce the chances
of a loss of vehicle control which can lead
to serious injury or death. If the rear end of
your vehicle slides while cornering, steer in
the direction of the slide until you regain
control of your vehicle.

Note: Excessive tire slippage can cause
transmission damage.

Four-wheel drive vehicles have advantages
over two-wheel drive vehicles in snow and
ice but can skid like any other vehicle.
Should you start to slide while driving on
snowy or icy roads, turn the steering wheel
in the direction of the slide until you regain
control.

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.

Avoid sudden braking. Although a
four-wheel drive vehicle may accelerate
better than a two-wheel drive vehicle in
snow and ice, it will not stop any faster as
braking occurs at all four wheels. Do not
become overconfident as to road
conditions.

Make sure you allow sufficient distance
between you and other vehicles for
stopping. Drive slower than usual and
consider using one of the lower gears. In
emergency stopping situations, apply the
brake steadily. Do not pump the brake
pedal. See Hints on Driving With
Anti-Lock Brakes (page 229).

If Your Vehicle Gets Stuck In Mud or
Snow

WARNING

Do not spin the wheels at over
34 mph (55 km/h). The tires may fail
and injure a passenger or bystander.

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

Note: Do not rock your vehicle if the engine
is not at normal operating temperature,
damage to the transmission may occur.

Note: Do not rock your vehicle for more
than a minute, damage to the transmission
and tires may occur or the engine may
overheat.

Parking

WARNINGS

If the parking brake is fully released,
but the brake warning lamp remains
illuminated, the brakes may not be

working properly. Have your vehicle
checked as soon as possible.

Always set the parking brake and
leave your vehicle with the
transmission in park (P).

On some four-wheel drive vehicles, when
the transfer case is in the N (Neutral)
position, the engine and transmission are
disconnected from the rest of the driveline.
Therefore, the vehicle is free to roll even if
the automatic transmission is in P (Park)
or the manual transmission is in gear. Do
not leave the vehicle unattended with the
transfer case in the N (Neutral) position.
Always set the parking brake fully and turn
off the ignition when leaving the vehicle.

(If Equipped)

Maintenance and Modifications

The suspension and steering systems on
your vehicle have been designed and
tested to provide predictable performance
whether loaded or empty. For this reason,
we strongly recommend that you do not
make modifications such as adding or
removing parts (i.e. lift kits or stabilizer
bars) or by using replacement parts not
equivalent to the original factory
equipment.

We recommend that you use caution when
your vehicle has either a high load or device
(i.e. ladder or luggage racks). Any
modifications to your vehicle that raise the
center of gravity may cause your vehicle
to roll over when there is a loss of vehicle
control.

Failure to maintain your vehicle correctly
may void the warranty, increase your repair
cost, reduce vehicle performance and
operational capabilities and adversely
affect you and your passenger's safety. We
recommend you frequently inspect your
vehicle's chassis components when your
vehicle is subject to off road usage.

(If Equipped)

LIMITED SLIP DIFFERENTIAL

This axle provides added traction on
slippery surfaces, particularly when one
wheel is on a poor traction surface. Under
normal conditions, the limited-slip axle
functions like a standard rear axle. The axle
may exhibit a slight noise or vibration
during tight turns with low vehicle speed.
This is normal behavior and indicates the
axle is working.

ELECTRONIC LOCKING
DIFFERENTIAL

(If Equipped)

Note: The electronic locking differential is
for off-road use only and is not for use on
dry pavement. Using the electronic locking
differential on dry pavement will result in
increased tire wear, noise and vibration.

The electronic locking differential is a
device housed in the rear axle that allows
both rear wheels to turn at the same
speed. The electronic locking differential
can provide additional traction should your
vehicle become stuck. You can activate
the differential electronically and shift it
on the fly within the differential operating
speed range. The differential is for use in
mud, rocks, sand, or any off-road condition
where you need maximum traction. It is
not for use on dry pavement.

The following conditions will affect the
electronic locking differential:

•

The electronic locking differential will
not engage if your vehicle speed is
above 20 mph (32 km/h) in 4x2 or 4x4
High modes.

•

The electronic locking differential will
not engage if your vehicle speed is
above or 56 mph (90 km/h) in 4X4
Low.

•

The electronic locking differential may
not engage if you press your
accelerator pedal during an
engagement attempt. A message may
display in the instrument display
guiding you to release the accelerator
pedal.

•

In 4x2 or 4x4 High modes, the
electronic locking differential will
automatically disengage at speeds
above 25 mph (41 km/h) and will
automatically reengage at speeds
below 20 mph (32 km/h).

•

In 4L (4X4 low), the electronic locking
differential will automatically
disengage at speeds above 62 mph
(100 km/h) and will automatically
reengage at speeds below 56 mph
(90 km/h).

•

The AdvanceTrac system has the
ability to take over control of the
electronic locking differential and
disable it during driving maneuvers
when necessary.

When you switch the system on, if you do
not meet the required conditions for
electronic locking differential activation,
the instrument cluster will display the
appropriate information guiding you
through the proper activation process.

Activating the Electronic Locking
Differential

Note: Do not use electronic locking
differential on dry, hard surfaced roads.
Doing so will produce excessive noise,
vibration and increase tire wear.

Note: If the electronic locking differential
has difficulty disengaging, release the
accelerator pedal and turn the steering
wheel in the opposite direction while rolling.

For 4WD vehicles

E227398

Pull the 4WD control knob toward you.

For 2WD vehicles

E183740

Turn the control to ON.

E163170

Once the indicator light
illuminates in the information
display, both rear wheel axle

shafts will be locked together providing
added traction.

If the indicator does not come on, or the
indicator turns off while driving, one of the
following has occurred:

•

The vehicle speed is too high.

•

The left and right rear wheel speed
difference is too high during an
engagement attempt.

•

The system has malfunctioned and is
accompanied by a message in the
information display. See your
authorized Ford dealer for assistance.