Oscillating Axle Lockout Test; Free Wheeling Option; To Disengage Drive Motors And Brakes (Free Wheel) For Emergency Towing; To Engage Drive Motors And Brakes (Normal Operation) - JLG 600A Service And Maintenance Manual

3.3 OSCILLATING AXLE LOCKOUT TEST

LOCKOUT SYSTEM TEST MUST BE PERFORMED QUARTERLY, ANY TIME A SYS-
TEM COMPONENT IS REPLACED, OR WHEN IMPROPER SYSTEM OPERATION IS
SUSPECTED.
NOTE: Ensure boom is fully retracted, lowered, and centered
between drive wheels prior to beginning lockout cylinder
test.
1. Place a 6 in. (15.2 cm) high block with ascension ramp in
front of left front wheel.
2. From platform control station, activate machine
hydraulic system.
3. Place FUNCTION SPEED CONTROL and DRIVE SPEED/
TORQUE SELECT control switches to their respective
LOW positions.
4. Place DRIVE control lever to FORWARD position and
carefully drive machine up ascension ramp until left
front wheel is on top of block.
5. Carefully activate SWING control lever and position
boom over right side of machine.
6. With boom over right side of machine, place DRIVE
control lever to REVERSE and drive machine off of block
and ramp.
7. Have an assistant check to see that left front wheel
remains locked in position off of ground.
8. Carefully activate SWING control lever and return boom
to stowed position (centered between drive wheels).
When boom reaches center, stowed position, lockout
cylinders should release and allow wheel to rest on
ground, it may be necessary activate DRIVE to release
cylinders.
9. Place the 6 in. (15.2 cm) high block with ascension ramp
in front of right front wheel.
10. Place DRIVE control lever to FORWARD and carefully
drive machine up ascension ramp until right front wheel
is on top of block.
11. Carefully activate SWING control lever and position
boom over left side of machine.
12. With boom over left side of machine, place DRIVE
control lever to REVERSE and drive machine off of block
and ramp.
13. Have an assistant check to see that right front wheel
remains locked in position off of ground.
14. Carefully activate SWING control lever and return boom
to stowed position (centered between drive wheels).
When boom reaches center, stowed position, lockout
cylinders should release and allow wheel to rest on
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SECTION 3 - CHASSIS & TURNTABLE
ground, it may be necessary activate DRIVE to release
cylinders.
15. If lockout cylinders do not function properly, have
trained personnel correct the malfunction prior to any
further operation.

3.4 FREE WHEELING OPTION

To Disengage Drive Motors and Brakes (Free Wheel)
for Emergency Towing
1. Chock wheels securely if not on flat level surface.
2. Disconnect both drive hubs by reversing the disconnect
caps in the center of the hubs.
3. If equipped, move steer/tow selector valve to float (tow)
position by pulling control knob out.
To Engage Drive Motors and Brakes (Normal
Operation)
1. If equipped, move steer/tow valve to steer position by
pushing valve knob in.
2. Connect both drive hubs by inverting disconnect cap in
center of hub.
3. Remove chocks from wheels as required.
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