2021 FORD F-350 lock

Note:
4x4 low mode is not intended for use
on dry pavement.
1. Bring the vehicle to a speed of 3 mph
(5 km/h) or less.
2. Place the transmission in neutral (N).
3. Move the 4WD control to the preferred
position.
The information display will display a
message indicating a 4X4 shift is in
progress. The information display will then
display the system mode selected. If any
of the above shift conditions are not met,
the shift will not occur and the information
display will display information guiding the
driver through the proper shifting
procedures.
If a message in the information display
shows a Shift Delayed Pull Forward
message, a transfer case gear tooth
blockage is present. To alleviate this
condition, place the transmission in a
forward gear, move the vehicle forward
approximately
5 ft (1.5 m), and shift the
transmission back to neutral to allow the
transfer case to complete the range shift.
Entering and Exiting Rock Crawl
Mode with Tremor Package
(If
Equipped) •
To enter rock crawl, your vehicle must
be in 4x4 low.
• Press the drive mode button on the
shifter column to bring up the
information display and select rock
crawl mode.
• With the switch in 4x4 low position,
press rock crawl mode again to
deactivate it. •
You can now perform a shift out of 4x4
low.
• Refer to Shifting to or from 4L (4x4
low) as described previously for proper
operation of 4x4 low in this procedure.
Operating 4WD Vehicles with
Spare or Mismatched Tires
On four-wheel drive vehicles, the size of
the spare tire can affect the 4X4 system.
If there is a significant difference between
the size of the spare tire and the remaining
tires, you may have limited four-wheel
drive functionality.
When driving with the full-size, dissimilar
spare wheel and tire assembly, we
recommend that you do not:
• Exceed
50 mph (80 km/h) with a 4WD
mode turned on.
• Turn on a 4WD mode unless the
vehicle is stationary.
• Use a 4WD mode on dry pavement.
When driving with the full-size, dissimilar
spare wheel and tire assembly, you may
have limited 4WD functionality, especially
when driving in a mechanically locked 4WD
mode. You may experience the following:
• Additional noise from the transfer case
or other drive components.
• Difficulty shifting out of a mechanically
locked 4WD mode.
Use of a dissimilar spare wheel and tire
assembly may lead to impairment of the
following:
• Comfort and noise.
• Winter weather driving capability.
• Wet driving capability.
• Four-wheel drive capability.
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How Your Vehicle Differs from
Other Vehicles
WARNING: Vehicles with a higher
center of gravity (utility and four-wheel
drive vehicles) handle differently than
vehicles with a lower center of gravity
(passenger cars). Avoid sharp turns,
excessive speed and abrupt steering in
these vehicles. Failure to drive cautiously
increases the risk of losing control of your
vehicle, vehicle rollover, personal injury
and death.
Truck and utility vehicles can differ from
some other vehicles. Your vehicle may be
higher to allow it to travel over rough
terrain without getting hung up or
damaging underbody components.
The differences that make your vehicle so
versatile also make it handle differently
than an ordinary passenger car.
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. To maintain steering and braking
control of your vehicle, you must have all
four wheels on the ground and they must
be rolling, not sliding or spinning. Driving Off-Road With Truck and
Utility Vehicles
Note:
On some models, the initial shift from
two-wheel drive to four-wheel drive 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.
Note: Your vehicle may come with a front
air dam that can become damaged (due to
reduced ground clearance) when taking your
vehicle off-road. This air dam can be taken
off by removing 15 bolts.
Four-wheel drive vehicles are specially
equipped for driving on sand, snow, mud
and rough terrain and have operating
characteristics that are somewhat
different from conventional vehicles, both
on and off the road.
Power is supplied to all four wheels
through a transfer case. On four-wheel
drive vehicles, the transfer case allows you
to select 4WD when necessary.
Information on transfer case operation and
shifting procedures can be found in this
chapter. Information on transfer case
maintenance can be found in the
Maintenance chapter. You should become
thoroughly familiar with this information
before you operate your vehicle.
Four-wheel drive (when you select a 4WD
mode) uses all four wheels to power the
vehicle. This increases traction, enabling
you to drive over terrain and road
conditions that a conventional two-wheel
drive vehicle cannot.
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(If Equipped)

After driving through mud, clean off residue
stuck to rotating driveshafts and tires.
Excess mud stuck on tires and rotating
driveshafts can cause an imbalance that
could damage drive components.
Water
If you must drive through high water, drive
slowly. Traction or brake capability may
be limited.
When driving through water, determine the
depth and avoid water higher than the
bottom of the hubs. If the ignition system
gets wet, your vehicle may stall.
Once through water, always try the brakes.
Wet brakes do not stop your vehicle as
effectively as dry brakes. Drying can be
improved by applying light pressure to the
brake pedal while moving slowly.
Note:
Driving through deep water may
damage the transmission. If the front or rear
axle is submerged in water, the axle
lubricant and power transfer unit lubricant
should be checked and changed if
necessary.
Driving on Hilly or Sloping Terrain
Although natural obstacles may make it
necessary to travel diagonally up or down
a hill or steep incline, you should always
try to drive straight up or straight down.
Note: Avoid turning on steep slopes or
hills. A danger lies in losing traction, slipping
sideways and possible vehicle roll over.
Whenever driving on a hill, determine
beforehand the route you will use. Do not
drive over the crest of a hill without seeing
what conditions are on the other side. Do
not drive in reverse over a hill without the
aid of an observer.
When climbing a steep slope or 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. If your vehicle stalls, do not try to turn
around because this could cause vehicle
roll over. It is better to reverse back to a
safe location.
Apply just enough power to the wheels to
climb the hill. Too much power will cause
the tires to slip, spin or lose traction,
resulting in loss of vehicle control.
Descend a hill in the same gear you would
use to climb up the hill to avoid excessive
brake application and brake overheating.
Do not descend in neutral. Disengage
overdrive or move the transmission
selector lever to a lower gear. When
descending a steep hill, avoid sudden hard
braking as you could lose control. The front
wheels have to be turning in order to steer
your vehicle.
If your vehicle has anti-lock brakes, apply
the brakes steadily. Do not pump the
brakes.
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
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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 225).
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 WARNING:
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. WARNING:
Apply the parking
brake, shift into park (P), switch the
ignition off and remove the key before
you leave your vehicle. Failure to follow
this instruction could result in personal
injury or death.
On some four-wheel drive vehicles, when
the transfer case is in the neutral (N)
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 park (P)
or the manual transmission is in gear. Do
not leave the vehicle unattended with the
transfer case in the neutral (N) position.
Always set the parking brake fully and turn
off the ignition when leaving the vehicle.
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(If Equipped)

LIMITED SLIP DIFFERENTIAL
(IF EQUIPPED)
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, and 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.
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For 4WD vehicles
Pull the 4WD control knob toward you.
For 2WD vehicles
Turn the control to ON.
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.
• The vehicle is experiencing an anti-lock
brake activation.
Operating ELD With a Spare or
Mismatched Tires
On vehicles with an ELD, the size of the
spare tire can affect performance of the
system. If there is a significant difference
between the two rear tires, you may have
limited ELD functionality. If the electronic
locking differential has difficulty
disengaging, release the accelerator pedal
and turn the steering wheel in the opposite
direction when rolling. We recommend
engaging and disengaging the ELD at a
stop when you mount a spare on the rear
axle.
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GENERAL INFORMATION
Note:
Occasional brake noise is normal. If
a metal-to-metal, continuous grinding or
continuous squeal sound is present, the
brake linings may be worn-out. Have the
system checked by an authorized dealer. If
your vehicle has continuous vibration or
shudder in the steering wheel while braking,
have it checked by an authorized dealer.
Note: Brake dust may accumulate on the
wheels, even under normal driving
conditions. Some dust is inevitable as the
brakes wear and does not contribute to
brake noise.
Wet brakes result in reduced braking
efficiency. Gently press the brake pedal a
few times when driving from a car wash or
standing water to dry the brakes.
Brake Over Accelerator
In the event the accelerator pedal
becomes stuck or entrapped, apply steady
and firm pressure to the brake pedal to
slow the vehicle and reduce engine power.
If you experience this condition, apply the
brakes and bring your vehicle to a safe
stop. Shift the transmission to park (P),
switch the engine off and apply the parking
brake. Inspect the accelerator pedal for
any interference. If none are found and the
condition persists, have your vehicle towed
to the nearest authorized dealer.
Brake Assist
Brake assist detects when you brake
rapidly by measuring the rate at which you
press the brake pedal. It provides
maximum braking efficiency as long as you
press the pedal, and can reduce stopping
distances in critical situations. Anti-lock Brake System
This system helps you maintain steering
control during emergency stops by keeping
the brakes from locking. This lamp momentarily
illuminates when you switch the
ignition on. If the light does not
illuminate during start up, remains on or
flashes, the system may be disabled. Have
the system checked by an authorized
dealer. If the anti-lock brake system is
disabled, normal braking is still effective.
See Warning Lamps and Indicators
(page 105).
Note: Indicators vary depending on region. If the lamp remains illuminated
after you release the parking
brake, have the system checked
by an authorized dealer.
It also illuminates momentarily
when you switch the ignition on
to confirm the lamp is functional. If it does
not illuminate when you switch the ignition
on, or begins to flash at any time, have the
system checked by an authorized dealer.
Diesel Engine Exhaust Braking
(If
Equipped) WARNING:
Do not use tow/haul
when the road surface is slippery. Failure
to follow this instruction could result in
the loss of control of your vehicle. WARNING:
Do not use diesel
engine exhaust braking when the road
surface is slippery. Failure to follow this
instruction could result in the loss of
control of your vehicle.
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You can use this feature with tow/haul or
progressive range selection to provide
further increased engine braking. The
transmission automatically upshifts to
prevent the engine from entering the red
zone on the tachometer. See Automatic
Transmission (page 207).
HINTS ON DRIVING WITH
ANTI-LOCK BRAKES
The anti-lock brake system does not
eliminate the risks when:
• You drive too closely to the vehicle in
front of you.
• Your vehicle is hydroplaning.
• You take corners too fast.
• The road surface is poor.
Note: If the system activates, the brake
pedal could pulse and may travel further.
Maintain pressure on the brake pedal. You
may also hear a noise from the system. This
is normal.
PARKING BRAKE WARNING:
Always set the parking
brake fully and make sure the
transmission is placed in park (P). Failure
to set the parking brake and engage park
could result in vehicle roll-away, property
damage or bodily injury. Turn the ignition
to the lock position and remove the key
whenever you leave your vehicle.
Apply the parking brake whenever your
vehicle is parked. Press the pedal
downward to set the parking brake. The
brake warning lamp in the instrument
cluster will illuminate and remains
illuminated until the parking brake is
released. To release, pull the brake release lever
located at the lower left side of the
instrument panel.
If you are parking your vehicle on a grade
or with a trailer, press and hold the brake
pedal down, then set the parking brake.
There may be a little vehicle movement as
the parking brake sets to hold the vehicle's
weight. This is normal and should be no
reason for concern. If needed, press and
hold the service brake pedal down, then
try reapplying the parking brake. Chock the
wheels if required. If the parking brake
cannot hold the weight of the vehicle, the
parking brake may need to be serviced or
the vehicle may be overloaded.
HILL START ASSIST
WARNING:
The system does not
replace the parking brake. When you
leave your vehicle, always apply the
parking brake. WARNING:
You must remain in
your vehicle when the system turns on.
At all times, you are responsible for
controlling your vehicle, supervising the
system and intervening, if required.
Failure to take care may result in the loss
of control of your vehicle, serious
personal injury or death. WARNING:
The system will turn
off if a malfunction is apparent or if you
rev the engine excessively. Failure to take
care may result in the loss of control of
your vehicle, serious personal injury or
death.
The system makes it easier to pull away
when your vehicle is on a slope without the
need to use the parking brake.
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Super Duty (TFE) Canada/United States of America, enUSA, Edition date: 202008, Third-Printing- Brakes