operators_manual

CAUTION
DO NOT modify the air system and/or
control functionality on a factory instal-
led auxiliary axle(s). Modifying the fac-
tory operation of the pusher and/or tag
axle(s) will void your warranty, and can
cause equipment damage.
CAUTION
A change in tire size on either the aux-
iliary axles or the drive/steer axles can
change the calibration of the auxiliary
axles. If tires are installed with a differ-
ent loaded radius, the calibration pro-
cedure must be repeated. Failure to do
so can cause equipment damage.
Contact your dealer or axle manufacturer
to determine what the creep rating is for
your particular axle(s) and configuration.
Creep ratings are generally limited to the
following:
• Tandem rear axles only
• Straight trucks only
• Maximum spring mount centers per
axle manufacturers specifications
• Maximum tire static loaded radius
(SLR) per axle manufacturers
specifications
Pusher or Tag Suspension
Calibration
Perform this procedure at or near a weight
scale. Procedure can be performed while
parked on the weight scale if scale is
available. To obtain the desired axle load
distribution, you must correlate the
suspension air gauge pressure to the
actual axle load by scaling the axle
weight(s) and adjusting the pressure to
obtain the desired load. Once the desired
load or load range is achieved, document
the pressure-to-load ratio or setting for
future use.
NOTE
This procedure must be performed pri-
or to placing the vehicle into service.
Add: Perform this procedure at or near a
weight scale. Procedure can be performed
while parked on the weight scale if scale is
available.
Setting the
Pressure-to-
Load Ratio
To obtain the desired axle load
distribution, you must correlate the
suspension air gauge pressure to the
actual axle load by scaling the axle
weight(s) and adjusting the pressure to
obtain the desired load. Once the
desired load or load range is achieved,
document the pressure-to-load ratio or
setting for future use.
These instructions are general in nature.
For more specific instructions, review the
pusher or tag suspension manufacturers
maintenance manual or contact the
nearest authorized dealer.
1. Park the loaded vehicle on a level
surface with the wheels blocked.
2. Release vehicles spring brakes.
(Do not release for Liftable/Non-
Steerable pusher or tag axles)
3. Lower the pusher/tag axles with the
Axle Lift Control flip valve. (For
some non-liftable axles, inflate air
suspension)
4. Adjust the amount of load on each
axle by turning the Pressure
Regulator clockwise to increase
the load, or counterclockwise to
decrease the load. (The
suspension manufacturer may
publish pre-established Pressure-
to-Load Ratio Pressure Settings to
DRIVING - Axle and Suspension
174 Y53-6126-1A1 (01/21)
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