JLG BOOM LIFTS 120SXJ: Daily Functional Check

Axles, Extending and Retracting

• From the ground control, activate the machine hydraulic system and raise the boom. Extend the boom no more than 8 feet (2.4m).

• Position Steer/Axles valve, located at the front of the frame to Axles.

• Position boom over drive wheel end of machine. Remove axle lock pins.

• Position LIFT control down to DOWN and hold until drive wheels rise from the ground. It may be necessary to feather the lift control to maintain drive wheel elevation.

• With the aid of an assistant, position EXTENDABLE AXLE/STEER switch located on platform control console to EXTEND until axles are fully extended and the AXLES SET light is on. Install axle lock pins.

• Position LIFT control to UP to lower the machine; elevate the boom sufficiently and reposition the boom over the steer wheel end of the machine.

• Remove the tie rod lock pins, steer cylinder lock pin, and axle lock pins.

• Position LIFT control to DOWN and hold until the steer wheels rise from the ground; it may be necessary to feather the LIFT control to maintain wheel elevation.

• With the aid of an assistant, position EXTENDABLE AXLE/STEER which on platform console to EXTEND until axles are fully extended.

• Align steer wheels and insert tie rod lock pin, axle lock pins, and steer cylinder lock pins.

• Position LIFT control to UP to lower the machine steer wheels; position STEER/AXLES valve to STEER.

• Cycle the steer system in both directions to ensure the tie rods are properly locked.

• Remove any one of the axle lock pins. From the ground control, monitor the AXLE SET indicator and attempt to lift and telescope the boom. With an axle lock pin removed, you will not be able to lift the boom above horizontal or telescope out beyond 11.5 feet (3.5m). At these positions, the AXLES SET indicator will not light, indicating the axles are not extended and locked. If the light does not illuminate when the axles are extended and set and the pins installed, contact a qualified service technician before continuing operation.