JLG 600S Operation And Safety Manual page 38

SECTION 2 - USER RESPONSIBILITIES, MACHINE PREPARATION, AND INSPECTION
4. Swing the boom over either of the rear tires and ensure that
the Drive Orientation indicator illuminates and that the
Drive Orientation Override switch must be used for the drive
function to operate.
5.
With the machine positioned on a smooth, firm surface
within the limits of the maximum operating slope, elevate
the boom above 5 degrees of horizontal. Select high speed
drive mode. Carefully attempt to drive and ensure the drive
speed is reduced.
2-12 31215033