Bush Hog HDTH8, Operator'S Manual, Page: 107 / 172

HDTH 8 Finish Mower 09/20
Operation Section 4-5
© 2020 Alamo Group Inc.
OPERATION
OPERA
TION
Power Take Off (PTO)
NOTE: These mowers are designed for 540 RPM (PTO) speeds only.
Depending on the unit, the mower is designed to operate at a PTO speed of 540 or 1000 RPM. Most tractors
operate at either 540, or a combination of 540 and 1000 RPM PTO speeds. The operating speed of the mower
and tractor can be determined by the number of splines on the driveline yoke and PTO output shaft.
Those operating at 540 RPM will have a 6-spline 1-3/8” diameter shaft and those operating at 1000 RPM will
have a 20-spline 1-3/4” diameter or 21-spline 1-3/8” diameter shaft.
Note: Refer to the tractor owner’s manual
for instructions to change PTO speeds on models that operate at more than one speed.
If operating an older model tractor where the tractor’s transmission and PTO utilize one master clutch, an over-
running clutch must be used between the PTO output shaft and the driveline of the mower. An authorized tractor
dealer can provide the over-running clutch and its installation if needed. OPS-U- 0006_ARPM.
DO NOT use a PTO adapter to attach a non-matching Implement driveline to a Tractor
PTO. Use of an adapter can double the operating speed of the Implement resulting in ex-
cessive vibration, thrown objects, and blade and implement failure. Adapter use will also
change the working length of the driveline exposing unshielded driveline areas. Serious
bodily injury and/or equipment failure can result from using a PTO adapter. Consult an
authorized dealer for assistance if the Implement driveline does not match the Tractor
PTO. (S3PT-14)
Never operate the Tractor and Mower if the Implement input driveline is directly connected
to the Tractor transmission. Tractor braking distances can be substantially increased by
the momentum of the rotating Mower blades driving the Tractor transmission even though
the Tractor clutch has been disengaged. Install an over running clutch between the Tractor
PTO and the Mower driveline to prevent this potentially dangerous situation. (S3PT-16)
Tire Spacing (Figure 4-1)
Tractor tires should be set a minimum of 60”
(1.524 Centimeters) apart. Measured from inside
of the tire to inside of the tire.
Refer to the tractor Operator’s Manual or consult
an authorized dealer for instructions to change
tractor tire spacing.
(Figure 4-1)