Ford 750 2009 Owner's Manual page 131

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.
WARNING: 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.
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 Eaton UltraShift transmission
Refer to the operation Transmission Power Take Off section of the
UltraShift Driver Instructions Manual.
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.
2009 F-650/750 (f67)
Supplement
USA (fus)
Driving
131