Steer Cylinders; Rear Axle Oscillation Lockout System - Manitowoc RT9150E Service Maintenance Manual

RT9150E SERVICE MANUAL
Functional Check
1. Cycle each outrigger cylinder several times. Verify each
cylinder extends and retracts properly.
2. Activate the rear steer function and steer to the left and
right several times. Verify the crane steers properly in
both directions.
3. Check the valve and lines for leakage. Make repairs as
needed.
NOTE: For further information on the integrated outrigger/
rear steer valve, refer to Outrigger/Rear Steer/
Outrigger Box Pin Removal Valve, page 2-37.

Steer Cylinders

Description
The steer cylinders are mounted on the axles, two cylinders
on each axle. The barrel end of each cylinder is attached to
the axle housing and the rod end is attached to the steering
lug on the axle end. The front steer cylinders are controlled
hydraulically by the front steer control valve through the steer
directional valve. The rear steer cylinders are controlled by a
solenoid valve located in the integrated outrigger /rear steer
valve.
Maintenance
NOTE: For Disassembly and Assembly procedures, refer
to Cylinders, page 2-63.
Removal
1. Tag and disconnect the hydraulic lines going into the
steer cylinder. Cap or plug all openings.
2. Remove the capscrew, flatwasher, and lockwashers
securing each pin weld in the rod end and barrel end of
the cylinder.
NOTE: Steer cylinder weighs approximately 44 lb (20 kg).
3. Remove both pin weldments and two thrust washers
(rod end only), and remove the cylinder from the axle.
Installation
1. Position the cylinder onto the attachment fittings on the
axle and install both pin weldments. On the rod end,
install a thrust washer on the top and bottom of lug.
2. Secure each pin weldment with the capscrew,
flatwasher and lockwasher. Torque the bolts according
GROVE
to the specifications in Fasteners and Torque Values,
page 1-17.
3. Connect the hydraulic lines to the cylinder as tagged
during removal.
4. Operate the steering system and check the cylinder for
proper operation and any leakage.

Rear Axle Oscillation Lockout System

Description
The rear axle oscillation system (Figure 8-3) consists of two
lockout cylinders, a lockout valve, an axle oscillation relay,
and an area definition potentiometer. The lockout cylinders
are mounted between a cradle (fifth wheel) and the carrier
frame. The lockout valve is mounted on the left inner center
frame rail and hydraulically controls the oscillating abilities of
the lockout cylinders.
Theory of Operation
The rear axle is mounted on a cradle (fifth wheel) allowing
maximum oscillation of 10 in (25 cm) total while traveling
over uneven terrain. Oscillation is provided only when the
superstructure is within 6 degrees left or right of directly over
the front. When the superstructure is within 6 degrees left or
r i g h t o f d i r e c t l y o v e r t h e f r o n t , t h e a r e a d e f i n i t i o n
potentiometer energizes the axle oscillation relay which in
turn energizes the solenoids on the lockout valve. When the
solenoids are energized, the valve spools are shifted to allow
hydraulic transfer between the two lockout cylinders.
As one side of the axle is forced up by traveling over uneven
terrain, the hydraulic fluid flows from the rod end of cylinder A
to the barrel end of cylinder B and from the rod end of
cylinder B to the barrel end of cylinder A (Figure 8-4). The
system is not pressurized and oil is moved from one cylinder
to the other by the action of the axle moving the cylinder.
When the superstructure is more than 6 degrees left or right
of directly over the front, the area definition potentiometer
de-energizes the axle oscillation relay. This de-energizes the
solenoids on the lockout valve and allows the springs in the
valve to shift the valve spools to the closed position to
prevent hydraulic fluid flow between the cylinders. By
stopping the flow of oil, a hydraulic lock is created and the
axle is held rigid in that position.
Published 1-16-2017 Control # 343-07
UNDERCARRIAGE
8-9
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