Maintenance Instructions
D21d
Checking and Servicing
78
PTO U-Joints
The PTO U-joints should be inspected
yearly
for
looseness and wear. If either is noticed, the
respective shaft or tube should be replaced. A
worn U-joint can cause vibration and extensive
damage to the PTO and the whole machine.
Safety Switch System
WARNING
It is important to check and maintain the
safety switch system for safe operation of
the machine.
There are four (4) safety interlock switches on the
tractor: Seat Switch, FSC Neutral-Park Switch,
PTO Switch, and Parking Brake Switch.
NOTE:
There is a 1/2 second time delay function
on the seat switch to avoid engine power interrup-
tion when driving over bumps.
If any of the following conditions occur during
starting or operating, a safety interlock switch may
be malfunctioning. Contact your Walker dealer for
troubleshooting and/or replacement.
● With or without an operator in the seat, the
engine starts
with the Forward Speed Control
(FSC) and/or the PTO engaged, or the parking
brake disengaged.
● With an operator in the seat and the parking
brake engaged,
the engine starts but dies
soon after the parking brake is disengaged and
the Forward Speed Control (FSC) or PTO is
engaged.
●
Without
an operator in the seat, the engine
starts and
continues to run
with the Forward
Speed Control (FSC) and/or PTO engaged, or
the parking brake disengaged.
● With an operator in the seat, the Forward
Speed Control (FSC) and PTO disengaged,
the parking brake engaged, and Oil Pressure
Warning Horn sounding, but the
starter will
not engage.
Forward Speed Control Friction Lock
The FSC friction lock is designed to
hold the
selected forward travel speed
when the steering
levers are moved and yet the friction is not too
heavy to make
moving the FSC control
difficult
(too much friction). The procedure for checking the
FSC friction lock is as follows:
1. With the engine off, place the FSC in the full
FORWARD
position and pull both steering
levers back; the FSC lever should not move.
If the FSC lever moves back when the steer-
ing levers are pulled back, the
friction needs
to be increased.
2. With the steering levers held back, move the
FSC lever back from the
FORWARD
position.
With a proper amount of friction adjusted, the
FSC lever should move back with a slight
amount of resistance (friction). If the FSC
lever movement is “stiff”, the
friction needs to
be decreased.
If the FSC friction lock needs to be adjusted, refer
to
Forward Speed Control Friction Lock on page
92.
