91
D21d
Maintenance Instructions
Adjustments
Blade Clutch (PTO)
Clutch Engagement/Belt Tension
The clutch engagement and PTO belt tension are
adjusted using the clutch actuator rod. Initially,
after installing a new PTO belt,
after 10 hours and
every 100 hours
thereafter, check and adjust for
the three dimensions in the clutch linkage as
shown.
Adjust the bolt head clearance [1/4 to 3/8 in.
(6 to 10 mm)] first, then adjust spring length. If
adjustments are needed more frequently than 100
hours to maintain the linkage dimensions, it may
suggest problems with pulley wear or belt misalign-
ment.
2-3/8 in.
(60 mm)
Clutch Linkage Adjustment - Disengaged
1/4 to 3/8 in.
(6 to 10 mm)
1-3/4 to 1-7/8 in.
(44 to 48 mm)
Clutch Linkage Adjustment - Engaged
Clutch Disengagement/Brake Action
WARNING
It is important to check and maintain blade
brake action for safe operation of the ma-
chine.
The
declutched or disengaged
position of the
blade clutch idler pulley is adjustable and is set to
give belt release
without excessive slack
and to
apply the blade brake. The blade brake is activat-
ed by linkage to the clutch idler pulley mechanism.
The brake is designed to stop the blades within
five (5) seconds after disengaging the clutch.
Use the following procedure to check and adjust
clutch disengagement and brake action:
1. Use the adjustment nut on the brake band
(refer to
PTO Clutch Disengagement Adjust-
ment
illustration) to set the position of the
clutch idler pulley in the
declutched
position.
Adjust the declutched pulley position to give
1/2 in. (13 mm) pulley travel
from “clutch
engaged” to “clutch disengaged.” To check
and adjust the pulley travel, first engage the
clutch, then measure the distance the pulley
moves down as the clutch is disengaged.
2. After the pulley travel is set,
check blade
brake
action as described in
Blade Brake
Action on page 77.
If the brake does not
stop the blades within five (5) seconds, check
the following:
a.
Check clearance between the clutch idler
pulley and the motor mount when the
pulley is in the declutched position. If
there is no clearance and the idler pulley
rests on the frame, the blade brake will not
be applied when the clutch is disengaged.
Normally, this problem would be caused by
a short engine PTO drive belt. Change the
belt (refer to
Drive Belts on page 79
),
and readjust pulley travel as described by
step 1 (above).