Service Manual

Traction Control Cable Adjustment (cont'd)
cable is the traction control, squeeze the control
bar toward the handle and note which cable
sheath moves.) See Figure 51.
2. Move the jam nuts either up
or down until you feel
slight resistance when the control
bar is 40 mm
(1-1/2)' from the handle.
NOTE: Make sure that the
two halves of the
traction control cable sheath are properly mated
when performing this adjustment.
NOTE: 1990
and newer units will have 'fingertip
adjustable' cables
that do not require tools for
adjustment. See Figure 52.
ADJUSTMENT KNOB
Figure 52
3. Once proper adjustment is attained, tighten the
jam nuts by rotating in opposite directions.
4. Test for proper operation and repeat adjustment
if necessary.
REAR HEIGHT-OF-CUT SYSTEM (HOC) AND
WHEEL PINION CLUTCH (WPC)
Rear HOC and WPC Operation
Rear Height-Or-Cut System: The rear height-of-cut
system is similar to the front height-of-cut system. By
fastening the wheel to pivoting brackets called pivot
arms,
the height-of-cut can be changed from 25 to 75
mm in 13 mm increments (1' to
3' in 1/2" increments).
The spring arms hold
the pivot arms in their desired
position through the use
of a small rivet which drops
into recesses
in the housing.
The rear height-of-cut system is a
bit more complex in
that not only must the wheels pivot, but they must also
drive. This is accomplished by running the output shaft
from the transmission through the pivot point on the
pivot arms. The pinion at the end of the output shaft
drives
the wheel gear which is permanently affixed to
the wheel. Because the output shaft passes through
the pivot point on the pivot arm, mating
of the two gears
Self-Propel System
38
is not affected by changing the height-of-cut. See
Figure
53.
PIVOT ARM
PINION GEAR
Figure 53
Wheel Pinion Clutch: The wheel pinion clutch has a
three-fold purpose. One, when the transmission
is
engaged, it causes the pinions to move with the output
shaft and drives the wheels. Two,
it provides differential
action to allow easy turning and excellent
maneuverability. Three,
it disengages the wheel
pinions from the output shaft when the operator is not
squeezing the handle. This allows the wheels to turn
backwards without turning the gears inside
the
transmission and provides pullback forces similar to
those found on a hand-push version.
Figure
54 shows a breakdown of the wheel pinion
clutch system. The letters
in the illustration refer to the
explanations
of each component function below.
k
Figure 54
a. Output Shaft -turns when the operator squeezes
the handle to provide power
to the wheels.
b. Pivot Arm provides support for the output shaft
with a bushing and a needle bearing.
It can be
rotated in the end cap to change height-of-cut.
Vacu-Power Mower