
Allison 3000 series push-button shifter
To shift the transmission into R
(Reverse) or D (Drive), depress the
brake pedal, then press R or D, then
release the brake pedal. To select a
lower range when in D (Drive),
press the down-arrow button. To
select a higher range when in D
(Drive), press the up-arrow button.
To place the transmission in N
(Neutral), press N.
Automatic transmission fluid operating temperatures
Allison 2200/2500 – The sump/fluid reservoir temperatures should not
exceed 250°F (120°C). The converter temperature should not exceed
300°F (144°C).
CLUTCH (IF EQUIPPED)
Do not ride or slip the clutch as this will cause unnecessary heat and
wear. Maintain the specified clutch adjustment to prolong its life and
regularly inspect the clutch control linkage for tightness. Refer to the
Scheduled Maintenance Guidechapter for other maintenance
information. When adjustment of the clutch is necessary, it is very
important that the work be performed properly or early clutch failure
may result and a costly clutch overhaul may become necessary. Clutch
work should only be performed by a qualified technician.
Engaging the clutch
•Always start in the proper gear.An empty vehicle can start in a
higher gear than a fully loaded vehicle. Starting in too high a gear can
cause clutch slippage and excessive heat and wear on the clutch. A
gear that will start the vehicle moving at idle speed is the correct gear.
If the engine has to be revved to get the vehicle going, the gear
selection is too high.
•Do not shift until the vehicle has reached the proper speed.
Upshifting before the vehicle has reached the proper speed can cause
clutch slippage and excessive heat and wear on the clutch.
•Never hold a vehicle on a grade with the clutch.This will cause
the clutch to slip and can actually burn up the clutch.
•Never coast with the clutch disengaged.The high RPM
(sometimes over 10,000), can actually burst the facing material of the
clutch.
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
117

To go forward
With the engine idling, depress the clutch pedal and shift into 1 (First).
Engage the clutch while pressing the accelerator to start forward.
Operate the clutch and upshift as required by driving conditions.
To go backward
Reverse is obtained by putting the gearshift lever in R (Reverse) and
engaging the clutch while pressing lightly on the accelerator.
POWER TAKE-OFF (PTO) OPERATION (IF EQUIPPED)
Vehicles equipped with an Allison automatic transmission
(except 3000 Series applications and vehicles equipped with a
Caterpillar engine)
The PTO can be operated while the vehicle is standing or moving. To
engage the PTO, apply the brakes and shift to any gear other than N
(Neutral), then engage the PTO.
If engagement is prevented by the gear teeth not meshing properly,
release the brakes and allow the vehicle to creep slightly or shift the
selector to N (Neutral) and then back into gear. The PTO should never
be engaged by clashing the gear teeth as this may damage the PTO unit
and the transmission PTO drive gear teeth. This could result in further
damage to the transmission and PTO.
PTO operation with vehicle stationary
Stop the vehicle, idle the engine and set the parking brake. Make sure
the gear selector is in any forward drive range, then engage the PTO.
After the PTO is engaged, move the range selector to N (Neutral).
Increase the engine speed until the desired power take-off operation
speed is obtained. To disengage the PTO after operation with the vehicle
standing, release the throttle, allow the drive equipment to come to a
stop, and then disengage the PTO.
When the PTO is operated with the vehicle stationary, the
transmission must be placed in N (Neutral) with the parking
brake set. If the transmission is not in N (Neutral) and is equipped
with a remote throttle control, an increase in engine speed can
overpower the parking brake and cause the vehicle to move, possibly
resulting in personal injury and/or property damage.
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
122

PTO operation while vehicle is moving
After the PTO is engaged for driven vehicle operation, shift to the
desired range and drive the vehicle. The speed of the PTO, during this
period of operation, will always maintain direct relation to vehicle speed.
PTO speed will decrease in relation to vehicle (transmission output)
speed as shifts to a higher gear occur. When operating the PTO while the
vehicle is moving, the PTO may be disengaged whenever it is no longer
required. When there is no load on the PTO gear, it can be pulled out of
engagement.
Vehicles equipped with an Allison 3000 Series automatic
transmission
The PTO drive gear is engine driven and provides direct engine power.
The PTO can be operated when the vehicle is either stationary or
moving.
The PTO gear is in constant mesh with the drive gear in the torque
converter housing. A friction clutch or constant drive is used to transmit
power to the PTO.
Vehicles equipped with a Caterpillar engine
The PTO will only operate if the transmission is in N (Neutral). This
feature can be overridden by a special service tool; see your dealer or
service representative for more information.
Vehicles equipped with a manual transmission
Transmission-mounted PTO units are available for local installation on
your vehicle. See yourBody Builder’s Layout Bookfor restrictions on
use and installation of PTO units.
To engage the PTO unit, stop the vehicle and place the transmission in N
(Neutral). Depress the clutch and allow the gears to stop rotating, then
engage the PTO unit. The PTO can also be selected with the
transmission in gear as long as the clutch is depressed.
When operating the PTO with the vehicle stationary, first set the parking
brake (chock the wheels if the vehicle is on a hill or another uneven
surface).
REAR AXLE INFORMATION
Axle operating temperature normally will not exceed 100°F (38°C). If
the operating temperature exceeds 230°F (110°C), the rate of axle
lubrication oxidation will increase and shorten the life of the lubricant
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
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Some Dana/Spicer drive axles have a driver-controlled differential lock.
The differential lock can lock or unlock the differential when the vehicle
is moving or stopped. When extra traction is required, the differential
lock will provide full power to both axles.
When the differential is locked, the vehicle’s turning radius will increase
(vehicle will “under-steer”)
The differential can be locked or unlocked when the vehicle is moving at
a constant speed of less than 25 mph (40 km/h) and while the wheels
are not slipping. The differential must not be locked when the vehicle is
traveling down steep grades and traction is minimal.
Note:Never use the differential lock at vehicle speeds above 25 mph
(40 km/h).
Note:The driver-controlled differential lock function will vary with some
transmissions.
•Vehicles equipped with an Allison 3000 Series transmission:The
differential lock and differential lock light will automatically disengage
at speeds above 25 mph (40 km/h). The differential lock will remain
off until either the vehicle is restarted or the differential lock switch is
turned off then back on.
•Vehicles equipped with a 5–speed, 6–speed or 7–speed manual:
The differential lock and differential lock light will automatically
disengage at speeds above 25 mph (40 km/h). The differential lock
will remain off until either the vehicle is restarted or the differential
lock switch is turned off then back on.
Axle conversions
It is not recommended, or approved, for axle conversions to be
performed. However, it is understood that, on occasion, aftermarket
add-on axles are installed by others on the truck chassis which allow
operator control for weight transfer from other axles (i.e., air lift axles).
When operating a loaded vehicle, the driver must keep all
adjustable axles on the ground at all times, supporting their
share of the vehicle’s load. Failure to do so can overload other axles,
tires, wheels, springs, steering components, brakes and frames,
resulting in early component failure, loss of vehicle control, possible
property damage and personal injury.
TWO-SPEED REAR AXLE (IF EQUIPPED)
A two-speed rear axle allows the driver to select a LO range for greater
pulling power and a HI range for greater road speed and fuel economy.
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
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These ranges can also be used to provide additional steps between
transmission shifts when driving on steep grades and/or fuel economy
may be factors.
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), then 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.
LOW
2SPD
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
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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.
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
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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.
2008 F-650/750(f67)
Supplement
USA(fus)
Driving
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for the engine control module. Refer toAutomatic transmission
operationin theDrivingchapter andBatteryin theMaintenance and
Specificationschapter 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 automatic transmission
vehicle. Automatic transmissions do not have push-start
capability. Attempting to push-start a vehicle with an automatic
transmission may cause transmission damage.
Before connecting a fast-charger, booster battery or installing a new
battery, make sure the ground polarities of the fast-charger, booster
battery or alternator (when installing a battery) are matched to the
ground polarity of the vehicle battery. Improper usage of the
fast-charger, hook-up of booster battery or installation of a new battery
can cause damage to the electrical system or to the alternator. Do not
attempt to polarize the alternator.
Preparing your vehicle
1.Use only a 12–volt supply to start your vehicle.Do not attach the
jumper cables to the glow plug relay as this could severely damage the
glow plugs, injector driver module and PCM.
2. Do not disconnect the battery of the disabled vehicle as this could
damage the vehicle’s electrical system.
3. Park the booster vehicle close to the hood of the disabled vehicle
making sure the two vehiclesdo nottouch. Set the parking brake on
both vehicles and stay clear of the engine cooling fan and other moving
parts.
4. Check all battery terminals and remove any excessive corrosion before
you attach the battery cables. Ensure that vent caps are tight and level.
5. Turn the heater fan on in both vehicles to protect from any electrical
surges. Turn all other accessories off.
2008 F-650/750(f67)
Supplement
USA(fus)
Roadside Emergencies
142