Gradall 544B Operation Manual - Manual (Page 20)

1.
2.
3.
4.
5.
1.
2.
3.
Rear Driving Axle
The rear driving axle includes planetary hubs which
are powered by hydraulic motors mounted on the
inner face of the hubs. Hydraulic flow to drive
motors is provided only in first and second gear
speed ranges. Drive motors are free- floating in third
gear.
travel functions only in first and second gears. There
is no hydraulic flow to drive motors in third gear.
Inching travel is controlled by the service
brake/inching travel pedal. This pedal has three
separate functions:
Continuous driving for two miles or more
in third gear, with rear driving hubs
engaged, can damage hydraulic drive
motors.
To Disengage Rear Driving Hubs:
Apply parking brake and remove key from
ignition switch.
Remove cap screws from pin keeper plate.
Remove and rotate plate (cup out - engaged - cup
in - disengaged).
Secure plate using cap screws.
Repeat procedure for other hub.
To engage Rear Driving Hubs: Repeat procedure.
NOTE: If machine is moved with pin keeper plate
removed, input shaft pin will pop out.
Hydraulic flow to rear axle drive motors is controlled
electrically. An automatic reset type breaker is
included to prevent damage from overload.
If circuit
breaker trips (opens) rear axle drive will be
inoperative for approximately ten seconds until
breaker resets. Notify maintenance personnel if
circuit breaker trips repeatedly.
To determine whether circuit breaker has tripped,
attempt to move machine using inching travel. If
machine does not respond to inching travel pedal,
circuit breaker is open.
Inching Travel
Inching travel is provided to permit very slow travel
while maintaining high engine speed for other
functions. Because inching travel depends on
hydraulic flow to rear axle drive motors, inching
18
It disconnects front drive axle from transmission.
It controls hydraulic flow to rear axle drive motors
(hydraulic flow equals speed).
It applies service brake.
As illustrated, the three functions occur in sequence
as pedal is depressed from top to bottom of stroke.
To Engage Inching Travel:
Depress service brake/inching travel pedal
approximately 1-1/2 inches to disengage front
driving axle from transmission. At this point rear
drive motors are receiving full flow and travel
speed will not have changed.
Continue to depress pedal to reduce speed - the
more pedal travel, the less speed.
To stop, depress pedal fully.
To resume normal travel, release service brake/
inching travel pedal. Depress accelerator pedal to
attain appropriate speed.
OR
Practice inching/braking in a sate, open
area until you are thoroughly familiar with
response of machine to pedal travel.
1.
2.
3.