Auxiliary Axles - Pusher Or Tag - Peterbilt 579 Operator's Manual

AXLE
LOW to HIGH (Cruising)
When you go from rough terrain to
highway driving, shift the axle to the
HIGH range following this procedure:
1. Be sure the differential is
UNLOCKED.
2. Maintain your vehicle speed
(accelerator depressed) and move
the Range Selector lever to HIGH.
3. Keep driving with the accelerator
4
depressed until you want the axle
to shift.
4. To make the axle shift, release the
accelerator until the axle shifts.
You are now in the HIGH axle
range for highway speeds. Shift
the transmission normally to reach
your desired cruising speed.
4-42
HIGH to LOW (Rough Terrain)
If you need to downshift the axle for
more power or you are driving on
rough terrain:
1. Maintain your vehicle speed
(accelerator depressed) and move
the Range Selector lever to LOW.
2. Keep driving with the accelerator
depressed until you want the axle
to downshift.
3. To make the axle downshift,
release and depress the
accelerator quickly to increase the
engine RPM. The axle will shift to
LOW range.
4. You are now in the LOW axle
range for rough terrain and heavy
loads. Shift the transmission
normally to maintain the desired
speed.
Y53-6047–2C
Auxiliary Axles - Pusher or
Tag
Adjustable auxiliary axles (commonly
known as Pusher or Tag axles) can
add to the productivity of the vehicle by
increasing the load capabilities of the
vehicle when they are in the deployed
(down) position. There are different
configurations of axles with different
functionality (liftable versus steerable).
Without the extra axle, the excessive
weight can reduce the service life
of vehicle components such as, but
not limited to, the frame rail, axles,
suspension and brakes.
Operation of the auxiliary axles
includes the proper maintenance of the
system and calibration of its controls.
Operating the auxiliary axles will also
require a firm understanding of the
(04/13)