Manitowoc Grove RT600E Operator's Manual page 92

OPERATING CONTROLS AND PROCEDURES
Front-Wheel
Four-Wheel
Secondary Steering (CE Units)
A secondary steering system is provided to backup the
normal front steering system if loss of hydraulic flow occurs.
This happens automatically when normal steering load
sense flow is lost. The pilot operated, two position, 3-way
valve will shift and supply flow from the accumulator to the
steer control valve to allow the operator to safely steer the
crane to a safe stop.
The LOW STEER PRESSURE (PRESS) indicator comes on
during pressure drops. This indicates the secondary steering
system should also be working.
Four-Wheel Drive Operation
CAUTION
Machine Damage Hazard!
Do not tow or pull in 1st gear with the Drive Axle Selector
Switch in two-wheel drive position. Severe damage to the
drive train will result. Always engage four-wheel drive.
If more traction is required due to slipping or spinning
wheels, engage the front axle drive as follows:
3-26
6402-1
Rear Wheel
6402-2
Crabbing
FIGURE 3-5
Published 05-02-2018 Control # 088-10
RT600E OPERATOR MANUAL
CAUTION
Possible Machine Damage!
Before shifting from two-wheel drive to four-wheel drive
(or from four back to two), crane travel must be stopped.
1. Stop the crane by depressing the Service Brake Foot
Pedal.
2. Position the Transmission Shift Lever to the neutral (N)
position.
3. Position the Drive Axle Selector Switch to four-wheel
low.
NOTE: If the Drive Axle Selector Switch is positioned to
four-wheel low and the Service Brake Foot Pedal is
not depressed or the Transmission Shift Lever is
not in neutral (N) position, the Four-Wheel Drive
Indicator will flash and the four-wheel drive function
will not engage.
4. Select gear speed and direction of travel using the
Transmission Shift Lever and Knob.
5. Drive the crane as described under Traveling —
Forward, page 3-25.
6. Return the Drive Axle Selector Switch to the two-wheel
high position as soon as two-wheel traction will suffice
and crane motion has stopped; again, the Service Brake
Foot Pedal must be depressed and the Transmission
Shift Lever must be in the neutral (N) position to shift
from four-wheel low to two-wheel high.
Differential Lock Operation (Optional)
CAUTION
Unexpected Operation!
When using the differential lock, steering characteristics
may be affected.
Try to use four-wheel drive to gain adequate traction
before using the differential lock.
Do not operate the differential lock when traveling
downhill; at speeds above 10 mph; on hard, dry surfaces;
and/or during axle spin-out.
NOTE: The differential lock will not operate unless the
Drive Selector Switch is in the four-wheel low
position.
General
The purpose of the differential lock is to provide maximum
traction and control on poor road or highway surfaces. When