Note:Do not shift between ranges when the speed control is on.
Never shift a two-speed axle when descending a steep grade as
this may cause loss of vehicle control and result in personal
injury.
Axle shifting
Manual transmissions:
•To downshift,select the next lower gear, release and depress the
accelerator pedal rapidly, or while holding the accelerator pedal down,
release and engage the clutch rapidly.Note:The clutch method is
recommended when driving at slower speeds.
•To upshift,keep the accelerator pedal down, select the next higher
gear, release the accelerator and pause until the axle upshifts.Note:
De-clutch for smoother axle upshifts when driving at slower speeds.
Automatic transmissions:
•Use LO range for when you drive
a fully loaded vehicle on a severe
grade or in congested traffic. To
activate LO range, press the
upper portion of the switch.
•Use HI range for all normal
driving conditions with a lightly
loaded or partially loaded vehicle.
To activate HI range, press the
lower portion of the switch.
Note:You cannot split-shift with an automatic transmission. Also,
downshifting above 40 mph (64 km/h) may result in transmission or axle
damage.
Shifting the axle from LO to HI range - vehicle stopped
Place the transmission in N (Neutral), the press the lower part of the
switch.
Shifting the axle from LO to HI range - vehicle moving
Accelerate to approximately 35 mph (56 km/h), press the lower part of
the switch while the transmission is in N (Neutral), then release and
apply the accelerator.
Shifting the axle from HI to LO range - vehicle stopped
Place the transmission in N (Neutral), then press the upper part of the
switch.
LOW
2SPD
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Note:Do not shift the axle to LO range with the vehicle in motion.
Split-shifting (combined axle and transmission shift - manual
transmissions only)
Split-shift sequence
Ratio
combination1234567891011
Transmission
gear1st 1st 2nd 2nd 3rd 3rd 4th 4th 5th 6th 6th
Axle range LO HI LO HI LO HI LO HI LO LO HI
To downshiftthe axle to a slower ratio and shift the transmission, shift
the transmission and move the control switch to the lower ratio before
the clutch is re-engaged.
To upshiftthe axle and shift the transmission, move the control switch
to a faster ratio and make the transmission shift in the usual manner.
Ratio extender use
Low End
A two-speed axle can be used as a ratio-extender when split shifting is
not necessary. For low end use, just shift the axle into the LO to start
out, and shift to HI when the extra torque is no longer needed.
Transmission
(5-speed)1st 1st 2nd 3rd 4th 5th 6th
Two-speed Axle Axle
LowAxle High
High End
To use the two-speed axle as a high end ratio-extender, stay in the LO
range for normal upshifts and only shift the axle to HI on the freeway for
greater road speed.
Transmission (5-speed) 1st 2nd 3rd 4th 5th 6th
Speed
Two-Speed Axle Low for Gradeability Axle
High
MAXIMUM VEHICLE LOADING
Every vehicle manufactured by Ford Motor Company is supplied with
information on the Vehicle Rating Decal listing the maximum loading for
the vehicle (GVWR), and its axle systems (GAWR) at the tire to ground
interface.
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When operating empty or lightly loaded, sudden or hard braking
may induce wheel lockup with loss of vehicle control and the
possibility of accident and serious injury, especially on wet or slippery
road surfaces.
TRAILER TOWING
Towing a trailer places an additional load on your vehicle’s engine,
transmission, axle, brakes, tires and suspension. Inspect these
components carefully prior to and after any towing operation.
Your vehicle’s load capacity is designated by weight, not by volume, so
you cannot necessarily use all available space when loading a vehicle.
2nd unit bodies are not included in maximum trailer weight ratings. The
weight of the additional “body” must be subtracted from the maximum
trailer weight.
Note:Do not exceed the GVWR or the GAWR specified on the
certification label.
Towing trailers beyond the maximum recommended gross trailer
weight exceeds the limit of the vehicle and could result in
engine damage, transmission damage, structural damage, loss of vehicle
control, vehicle rollover and personal injury.
Model Maximum
GVWR - lb.
(kg)Maximum
GCWR - lb.
(kg)*
F-650 Regular/Super/Crew Cab 26000 (11793) 40000 (18143)
F-750 Regular/Super/Crew Cab 30000 (13608) 45000 (20412)
F-750 Regular/Super/Crew Cab 33000 (14969) 60000 (27216)
* Figures shown are the maximum available for each model. Actual
ratings may be less, depending on your transmission. Check with your
sales consultant for the exact rating on your vehicle.
Preparing to tow
Use the proper equipment for towing a trailer and make sure it is
properly attached to your vehicle. See your dealer or a reliable trailer
dealer if you require assistance.
Hitches
Do not use hitches that clamp onto the vehicle’s bumper or attach to the
axle. You must distribute the load in your trailer so that 10–15% of the
total weight of the trailer is on the tongue.
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Safety chains
Always connect the trailer’s safety chains to the frame or hook retainers
of the vehicle hitch. To connect the trailer’s safety chains, cross the
chains under the trailer tongue and allow slack for turning corners.
If you use a rental trailer, follow the instructions that the rental agency
gives to you.
Do not attach safety chains to the bumper.
Trailer brakes
Electric brakes and manual, automatic or surge-type trailer brakes are
safe if installed properly and adjusted to the manufacturer’s
specifications. The trailer brakes must meet local and Federal
regulations.
Do not connect a trailer’s hydraulic brake system directly to your
vehicle’s brake system. Your vehicle may not have enough
braking power and your chances of having a collision greatly increase.
Trailer lamps
Trailer lamps are required on most towed vehicles. Your vehicle may be
equipped with one of two possible trailer wiring designs. Make sure all
running lights, brake lights, turn signals and hazard lights are working.
See your dealer or trailer rental agency for proper instructions and
equipment for hooking up trailer lamps.
Driving while you tow
When towing a trailer:
•Keep your speed no faster than 70 mph (112 km/h) during the first
500 miles (800 km) of towing a trailer, and don’t make full throttle
starts.
•Turn off the speed control. The speed control may shut off
automatically when you are towing on long, steep grades.
•Consult your local motor vehicle speed regulations for towing a trailer.
•To eliminate excessive transmission shifting, use a lower gear. This will
also assist in transmission cooling.
•Anticipate stops and brake gradually.
•Do not exceed the GCWR rating or transmission damage may occur.
Servicing after towing
If you tow a trailer for long distances, your vehicle will require more
frequent service intervals. Refer to yourScheduled Maintenance Guide
for more information.
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Trailer towing tips
•Practice turning, stopping and backing up before starting on a trip to
get the feel of the vehicle trailer combination. When turning, make
wider turns so the trailer wheels will clear curbs and other obstacles.
•Allow more distance for stopping with a trailer attached.
•If you are driving down a long or steep hill, shift to a lower gear. Do
not apply the brakes continuously, as they may overheat and become
less effective.
•The trailer tongue weight should be 10–15% of the loaded trailer
weight.
•If you will be towing a trailer frequently in hot weather, hilly
conditions, at GCW, or any combination of these factors, consider
refilling your rear axle with synthetic gear lube if not already so
equipped. Refer toLubricant Specificationsin theMaintenance
and Specificationschapter for the lubricant specification. Remember
that regardless of the rear axle lube used, do not tow a trailer for the
first 500 miles (800 km) of a new vehicle, and that the first 500 miles
(800 km) of towing be done at no faster than 70 mph (112 km/h) with
no full throttle starts.
•After you have traveled 50 miles (80 km), thoroughly check your
hitch, electrical connections and trailer wheel lug nuts.
•To aid in engine/transmission cooling and A/C efficiency during hot
weather while stopped in traffic, place the gearshift lever in P (Park)
(if available on your automatic transmission) or N (Neutral) (manual
transmissions and automatic transmissions withoutaP[Park]
position).
•Vehicles with trailers should not be parked on a grade. If you must
park on a grade, place wheel chocks under the trailer’s wheels.
FIFTH WHEEL OPERATION
Failure to follow the fifth wheel manufacturer’s instructions for
hooking and unhooking as well as sliding the fifth wheel could
result in an accident, personal injury or death.
When the tractor and trailer are parked unattended, the trailer
brake hand control should never be used to apply the brake,
since air may leak from the system, allowing vehicle movement,
resulting in possible property damage, personal injury or death.
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Fuse/Relay
LocationFuse Amp
RatingFuse Description
16 15A High beams
17 — Not used
18 5A Headlamp switch, GEM
19 15A Engine ECM (Caterpillar and Cummins engines)
Engine ECM, Accel, Crank (6.0L Power Stroke
engine only)
20 15A Starter relay, GEM
21 10A Daytime Running Lamps (DRL)
22 15A Air solenoid 4–pack (Air horn, Air suspension
dump, Differential lock axle and Two-speed
axle)
23 10A Electronic flasher
24 15A Vacuum pump, Air dryer, ABS, Fuel heater/Fuel
transfer pump relay, Heated drain valve, 6.0L
Power Stroke Water In Fuel (WIF) module
25 10A Blower motor relay
26 10A RH low beam headlamp
27 — Not used
28 10A LH low beam headlamp
29 10A Cluster (Power, Warning lamps), Hydraulic ABS
relay, Air traction control
30 30A Not used
31 15A Allison transmissions
Relay 1 — Interior lamps
Relay 2 — Not used
Relay 3 — Horn
Relay 4 — One-touch down window
Relay 5 — Not used
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Power distribution box
Always disconnect the battery before servicing high current
fuses.
Fuse/Relay
LocationFuse Amp
RatingFuse Description
1 15A* Park lamps, Roof lamps
2 30A* Power seat (driver)
3 30A* Power seat (passenger)
4 15A* Washer pump
5 15A* Exhaust brake (Caterpillar and Cummins
engines only)
6 15A* Air intake heater (Caterpillar engine only)
7 15A* Stoplamps
8 25A* Fuel heater (Caterpillar engine only)
20A* Fuel heater (6.0L Power Stroke engine only)
9 20A* Inhibit relay, Engine ECM, Cluster,
Transmission TCM
10 15A* Heated drain valve
11 — Not used
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Fuse/Relay
LocationFuse Amp
RatingDescription
R2 — Trailer tow stop lamp relay
R3 — Trailer tow park/marker lamp relay
R4 — Trailer tow tail lamp relay
R5 — Not used
R6 — Not used
R7 — Trailer tow left turn/stop lamp relay
(combined)
Trailer tow left turn lamp relay (separate)
R8 — Trailer tow right turn/stop lamp relay
(combined)
Trailer tow right turn lamp relay (separate)
*Maxi fuse
Inline fuses
Your vehicle has two inline fuses located in/on the battery cables by the
battery. A 10A fuse for the transmission control module and a 40A fuse
for the engine control module. Refer toAutomatic transmissionin the
Drivingchapter andBatteryin theMaintenance and Specifications
chapter for more information.
JUMP STARTING
The gases around the battery can explode if exposed to flames,
sparks, or lit cigarettes. An explosion could result in injury or
vehicle damage.
Batteries contain sulfuric acid which can burn skin, eyes and
clothing, if contacted.
Do not attempt to push-start your vehicle. Automatic
transmissions do not have push-start capability; doing so may
damage the catalytic converter.
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