
To avoid sudden, unexpected vehicle movement and possible
personal injury or death:
1. Bring the vehicle to a complete stop.
2. Shift the transmission into: N (Neutral).
3. Apply the parking brake and make sure it is holding properly.
4. Turn the engine off when you leave the vehicle.Never leave the
vehicle unattended when the engine is running.
Allison 2400 automatic transmission with park pawl feature
Note:For Allison automatic transmission-equipped vehicles, also refer to
the separate Allison Transmission Operator’s Manual.
A parking pawl effectively grounds the transmission’s output shaft
preventing rotation of the driveline. If the vehicle is stationary, selecting
the P (Park) position places the transmission in neutral and engages the
parking pawl (always use the parking brake, also).
Note:If the P (Park) position is selected when the vehicle is in motion,
the parking pawl mechanism will ratchet andNOThold the truck.
Always set the parking brake fully. Do not use the gearshift in
place of the parking brake.
To avoid sudden, unexpected vehicle movement and possible
personal injury or death:
1. Bring the vehicle to a complete stop.
2. Shift the transmission into: P (Park). Slowly lift your foot from the
brake pedal to engage the transmission parking pawl mechanism.
3. Apply the parking brake and make sure it is holding properly. Do not
rely solely on the parking mechanism of the transmission.)
4. Turn the engine off when you leave the vehicle.Never leave the
vehicle unattended when the engine is running.
Allison MD (Medium Duty) electronic World Transmission (WT)
Two modes are available for the Allison MD-WT: Performance and
Economy. Performance mode will give you the best all-around
transmission operation; Economy provides operation at lower engine
RPM while maintaining adequate performance. The transmission will
automatically default to Performance mode when you start the engine.
Pressing MODE on the shifter will activate the Economy mode; this will
also illuminate the Mode ON lamp.
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If the engine speed is above idle when a gear is selected using the
shifter, the vehicle will not move. To move the vehicle, the shifter must
be moved to re-select a gear after the engine speed returns to idle.
Note:For more information regarding the Allison MD-WT, refer to the
separate Allison MD-WT Operator’s Manual.
Torque lock
If your vehicle is parked on an incline and P (Park) is not properly
engaged (The parking brake is not applied before the transmission is
shifted into P [Park]), the weight of the vehicle may generate an
excessive amount of torque on the park pawl. In this situation, it may be
difficult to shift the transmission out of P (Park). Hold the brake pedal
down while shifting out of P (Park), then release the parking brake.
Allison MD (Medium Duty) 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 operating temperatures
Allison 2000/2400–The sump/fluid reservoir temperatures should not
exceed 120°C (250°F). The converter temperature should not exceed
144°C (300°F).
Power take-off (PTO) operation with an Allison automatic
transmission (except MD applications and vehicles equipped with
a Caterpillar 3126E engine)
The power take-off 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) - this stops the rotation of the PTO drive gear in the
transmission - then engage the PTO.
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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 in gear. The PTO should never be
engaged by clashing the gear teeth. 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
To operate the power take-off, 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 for stationary
vehicle operation, 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 and/or property damage.
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.
Power take-off (PTO) operation on vehicles equipped with a
Caterpillar engine
If your vehicle is equipped with a Caterpillar engine, the PTO will only
operate if the vehicle is in Neutral. This feature can be overridden by a
special service tool; see your dealer or service representative for more
information.
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If your vehicle’s transmission is equipped with a ceramic clutch, you
must start the vehicle moving in first gear and engage the clutch before
pressing the accelerator at idle. Also, don’t try to slip the clutch by
raising engine RPM and riding or feathering the clutch pedal since the
vehicle will experience erratic engagement. Erratic engagement can
cause the engine stalling and potential serious damage to the vehicle’s
driveline components.
Clutch brake (vehicles equipped with a non-synchronized
transmission) - Vehicle stationary
A clutch brake is used to stop the transmission input shaft rotation so
that the initial 1 (First) or R (Reverse) gear selection can be
accomplished when the vehicle is stationary and the engine is running at
idle speed. Clutch brake application occurs in the last 25 mm (one inch)
of clutch pedal travel.
When using the clutch brake, fully depress the clutch pedal and shift the
transmission into 1 (First) or R (Reverse). If the transmission won’tgo
into one of these gears, slowly release the clutch pedal while applying
light pressure on the transmission shift lever until it shifts into gear.
Note:After engagement of 1 (First) gear,do notuse the clutch brake
for upshifting or downshifting. If you do, clutch brake life will shorten
and gear selection shift efforts may increase.
Double-clutch procedures - vehicles equipped with a
non-synchronized transmission
In order to properly upshift or downshift, perform the following steps:
1. Depress the clutch pedal to disengage the clutch.
2. Shift the transmission in to neutral.
3. Release the clutch pedal.
If upshifting, wait until the engine speed matches the transmission
speed of the gear you are selecting.
If downshifting,accelerate the engine until the engine speed matches
the input speed of the gear you are selecting. Depress the clutch pedal
immediately and shift into the desired gear, then release the clutch
pedal.
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Shifting with a synchronized transmission
With the clutch pedal depressed, use 2 (Second) gear synchronizer to
stop the clutch disc rotation; this allows smooth engagement of 1 (First)
or R (Reverse) To complete the gear engagement, it may be necessary to
apply light pressure to the gearshift lever during initial engagement of
the clutch. It takes a second or two to match gear speeds; steady
pressure on the gearshift lever will help the synchronizer perform its job
more quickly. If the gearshift lever is forced into position, this action
defeats the purpose of the synchronizer by causing gear clash.
Shifting with a non-synchronized transmission
Refer toClutch brakeandDouble clutch proceduresin theClutch
section of this chapter.
Operating the Eaton FS-4205A and FS-5205A 5–speed
transmissions
The 5-speed transmission is
equipped with five forward gears
and one reverse. The 2nd, 3rd, 4th
and 5th gears are synchronized. The
shift pattern is embossed on the
gear shift knob.
Do not shift the transmission into R (Reverse) while the vehicle is
moving as this could damage the transmission.
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.
R 2 4
3 5 1
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Power-take off operation (PTO) with a manual transmission
Transmission-mounted power take-off units are available for local
installation on your vehicle. See your Body Builder’s Layout Book for
restrictions on use and installation of power take-off units.
To engage the PTO unit, stop the vehicle and place the transmission
control in 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 unit with the vehicle stationary, first set the
parking brake (chock the wheels if the vehicle is on a hill or other
unlevel surface).
REAR AXLE INFORMATION
Axle operating temperature normally will not exceed 38°C (100°F). If
the operating temperature exceeds 110°C (230°F), the rate of axle
lubrication oxidation will increase and shorten the life of the lubricant
and seals, requiring axle lubrication changes to become more frequent to
preserve the axle. Extreme Pressure (EP) lubricants should not be run
consistently above 110°C (230°F).
Gross axle weight
Your truck has gross axle weight, gross vehicle weight and gross
combination weight ratings. Do not exceed these ratings.
Exceeding these ratings by overloading can cause component
failure resulting in property damage, personal injury or death.
Rear axles with locking or limited-slip differentials
If your vehicle is equipped with a locking or limited-slip differential, note
the following:
•Power will be transmitted to the opposite wheel should one of the
wheels begin to slip.
•Both wheels must be raised free of the ground should it be necessary
to operate one wheel with the vehicle stationary.
If both wheels are not raised free of the ground, the one wheel
that is not raised may pull the vehicle off its support, possibly
resulting in personal injury
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Driver-controlled differential lock
To prevent the vehicle from moving when servicing the wheels, tires or
brakes, turn the engine off and raise all drive wheels of the locker
differential axle. Axles equipped with NoSPIN Detroit Locker differentials
deliver power to both wheels even when only one wheel is on the ground.
Failure to raise all drive wheels with this type of differential
could cause the vehicle to move unexpectedly, resulting in
property damage, personal injury or death.
Care should be taken to avoid sudden accelerations when both drive
wheels are on a slippery surface.
Sudden accelerations on slippery surfaces could cause the
wheels to spin, the vehicle to turn sideways on a crowned road
surface or in a turn, possibly resulting in loss of vehicle control and
personal injury.
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.
The differential can be locked or unlocked when the vehicle is moving at
a constant speed of less than 40 km/h (25 mph) and while the wheels
are not slipping. If the differential is locked and vehicle speed exceeds
40 km/h (25 mph), the differential will automatically unlock. Also, the
differential must not be locked when the vehicle is traveling down steep
grades and traction is minimal.
When the differential is locked, the vehicle’s turning radius will increase
(vehicle will“under-steer”)
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.
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•Canada
Under no circumstances should your vehicle be loaded in excess of the
GVWR or GAWR. It is the operator’s responsibility to assure that neither
the axle capacities, spring capacities, tire capacities nor the vehicle rated
GVWR is exceeded. For tire capacities, refer toMaintenance and
specificationschapter.
Unloaded or lightly loaded vehicles
The braking system has been designed to safely stop your vehicle when
fully loaded to its GVWR.
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.
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