Pierce Enforcer, Operator'S Manual

Page: 41 / 196

© 2018 Pierce Manufacturing Inc. All Rights Reserved.
Equipment, Accessories, and Adjustments / 3-11
BEFORE PLACING VEHICLE IN SERVICE
NFPA 1901 and 1906 specify that the apparatus when placed in service shall have a side-to-side tire load variation
of no more than 7% of the total tire load for that axle.
The projections of total equipment payload and mounting locations are essential for proper engineering of a new fire
apparatus. The purchaser of the fire apparatus should maintain the side-to-side loading requirement in (NFPA)
4.13.3.3 as equipment is loaded or installed on the apparatus. The percentage difference in side-to-side tire load
should be calculated as shown in the following formula:
After loading the apparatus to its in-service condition, weigh each wheel position independently to ensure that the
side-to-side specification is met. If the variation exceeds 7%, shift the load in the compartments until the
specification is met.
3-9. Front Spring/Suspension Adjustment
Refer to the following paragraphs for front spring/suspension adjustment information (if needed after equipment and
cargo has been loaded).
3-9.1 TAK-4™ Independent Front Suspension
Information concerning the ride height adjustment of the TAK-4™ Independent Front Suspension can be found in
the Pierce Service Manual, group 0152-P-007, TAK-4™ Torsion Bar Assembly.
3-9.2 Leaf Spring Suspension
• Remove factory installed shims. It is likely that any lean induced by the weight from factory installed options such
as ladder racks, high side compartments, and generators was corrected before the vehicle left Pierce by adding
shims between the spring pack and the axle pad. This action, although necessary to provide a level product as
delivered, may complicate the leveling process once equipment is added. If accurate scale measurements
indicated that the unit is equally loaded from side to side and an objectionable lean persists, inspect each spring
for the presence of shims. These shims may be removed to reduce the lean if they are located on one of the
high side springs.
• Adding shims. If all the above actions have been taken and an objectionable lean still persists, additional shims
may be installed on the low side of the vehicle. Shim thickness should not exceed 0.50 inches on the front and
1.00 inches on the rear. Appropriate shim stock may be ordered from the Pierce customer service department.
Shims must be installed in a manner that maintains the locating pin function between the axle and the springs.
U-bolts should be re-tightened to the specified torque after 500 miles of road operation. Contact Pierce
Customer Service concerning any shimming beyond these guidelines.
Excessive shimming of the front axle can adversely affect steering and braking performance.