Blue Bird Vision 2021, Driver'S Handbook Manual

Page: 114 / 210

5-22
D R I V E R S H A N D B O O K
Engaged Position (Locked)
1. Move the control switch to the “Lock” position; either while
the vehicle is stationary or while moving at steady speed
under 25 MPH without wheel differentiation (spinout).
2. Reduce pressure momentarily on the accelerator pedal to
relieve torque on the gearing and fully engage the sliding
clutch.
3. When the differential lock is engaged, the indicator light
will be on or an audible signal sounds.
With the cab switch in the Lock position the vehicle system air pres-
sure is applied to the shift system, which engages the differential
lock and both wheels will turn at the same speed.
NOTE: When the
differential lock is engaged, the vehicle under-steers, requiring a lon-
ger turning radius for a given turn.
Disengaged Position (Unlocked)
1. To disengage the wheel differential lock, move the control
switch to the “Unlock” position.
2. Reduce pressure on the accelerator pedal momentarily to
relieve torque and allow the sliding clutch to disengage.
3. When the differential lock is disengaged, the indicator
light and/or audible signal goes out.
With the cab switch in the Unlock position there is zero air pres-
sure to shift system and a spring is keeping the shift assembly in
the disengaged position.
NOTE: Occasionally the differential lock
may not disengage immediately due to torque “wrap up,” when this
occurs, drive normally for a short distance with the control switch still
in the “Unlock” position until normal road forces release the torque
wrap up condition.