Power Takeoff Operation; Engine-Driven Power Takeoff (Pto) - Allison Transmission Emergency Vehicle Series Operator's Manual

POWER TAKEOFF OPERATION

ENGINE-DRIVEN POWER TAKEOFF (PTO)

CAUTION: Do not exceed the engagement and operational speed limits
imposed on the driven equipment during the operation of the PTO.
Exceeding the speed limits produces high hydraulic pressure in the PTO
that can damage the PTO components. Consult the vehicle
manufacturer's literature for these speed limits.
If a PTO is present, it will normally be mounted on either the left or right side of
the 3000 Product Family transmission. On the 4000 Product Family transmission,
the PTO will be located on the left side or on the top of the transmission. The
PTO drive gear is engine-driven and therefore provides direct engine power. The
PTO can be operated when the vehicle is either moving or stopped.
The PTO gear is in constant mesh with the drive gear in the converter housing.
However, the PTO may either be constant-drive (output always powered) or
clutch-driven. When the PTO is clutch-driven, the clutch is part of the PTO, not
the transmission. A clutch-driven PTO is powered only when the PTO clutch is
engaged.
All 3000 and 4000 Product Family equipped vehicles with PTO enable have
engagement and operational speed limits programmed into the TCM/ECU to help
protect PTO equipment. Be sure the limits for PTO engagement speed and
operational speed are not exceeded. Consult the vehicle manufacturer's literature
for these speed limits. Some speed limits have default values which are
programmed out of the operating range and will need to be set for your particular
PTO duty cycle. Consult your vehicle manufacturer to see if your transmission has
been programmed and what operational limits have been established.
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