JLG M450 ANSI Service Manual - Manual (Page 51)

SECTION 3 - CHASSIS & TURNTABLE
3121127 – JLG Lift – 3-11
3.5 SPEED SENSOR ADJUSTMENT
For proper drive operation, the speed sensors must be
properly installed and adjusted. The sensor operates on a
leading pulse to show direction. If installed wrong, the
sensor will not be able to sense the proper direction.
IF BOTH SPEED SENSORS ARE INSTALLED WRONG, THE CON-
TROLLER WILL THINK THE MACHINE IS ON A HILL AND WILL GO
INTO FULL SPEED MODE IMMEDIATELY WHEN DRIVE IS
SELECTED. THE MACHINE WILL NOT STOP UNLESS THE FOOT-
SWITCH IS RELEASED OR THE EMS IS PUSHED IN.
IF ONLY ONE SENSOR IS INSTALLED WRONG, THE CONTROLLER
SENSES A PROBLEM AND THE MACHINE WILL ONLY DRIVE AT
CREEP SPEED. IF BOTH SENSORS ARE ADJUSTED TOO FAR OUT,
THE CONTROL SYSTEM CONTROLLER WILL NOT DRIVE THE
MACHINE.
Adjustment Procedure
1. Back off the locking nut and o-ring.
2. Thread the sensor in until it bottoms out (don’t use
excessive force).
3. Back-off 1-2 turns and align the notch with the axis
of the brake. Refer to Figure 3-3., Speed Sensor Ori-
entation.
4. Use a 1/2" wrench to hold the sensor and a 11/16"
wrench to snug the lock nut to the brake.