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17730-299
ULTIMAAX
®
for Fire and Rescue Vehicles
SECTION 1
Introduction
This publication is intended to acquaint and assist maintenance personnel in the preventive
maintenance, service, and repair of the ULTIMAAX
®
Rear Rubber Suspension System for applicable
Fire and Rescue Vehicles .
NOTE
Use only Hendrickson Genuine parts for servicing this suspension system .
It is important to read and understand the entire Technical Procedure publication prior to
performing any maintenance, service, or repair of this product . The information in this publica-
tion contains parts lists, safety information, product specifications, features, proper maintenance,
service, and repair instructions for ULTIMAAX suspensions .
Hendrickson reserves the right to make changes and improvements to its products and
publications at any time . Contact Hendrickson Tech Services for information on the latest version
of this manual at 1-866-755-5968 (toll-free U .S . and Canada), 1-630-910-2800 (outside U .S . and
Canada) or e-mail: techservices@hendrickson-intl .com .
The latest revision of this publication is available online at www.hendrickson-intl.com.
SECTION 2
Product Description
ULTIMAAX
is an advanced severe-duty rear rubber suspension designed specifically for fire and
rescue applications to balance outstanding durability, empty ride quality, loaded stability and
mobility . Through its unique design, the system offers premium ride quality in both empty and
loaded conditions, with increasing stability as the load increases .
■
Equalizing beam
— Formed and robotically welded to provide a narrow profile for weight
savings . Distributes load equally between axles to improve maneuverability, stability and
handling . Increases ground clearance with flat bottom design . Lowers the center of gravity to
increase stability .
■
Saddle
— Triangular geometry provides structure and durability . Weight efficient design
helps to increase payload, while offering a considerable weight savings versus competitive
suspensions .
■
Frame hangers
— Optimized design to balance durability and weight savings . Fabricated to
offer flexibility with multiple truck configurations .
■
Rubber shear springs
— Primary springs in unloaded condition, providing superb ride quality .
React to longitudinal loads during braking and accelerating for minimal displacement .
■
Progressive load springs
— Designed to balance empty ride quality and loaded stability .
Stiffness of progressive load spring increases as load increases, providing a unique balance
of empty ride quality and loaded stability .
■
Longitudinal torque rods
— Engineered to optimize resistance to axle wind-up during accel-
eration and braking .
■
Transverse torque rods
— Heavy-duty transverse torque rods ensure maximum lateral axle
control and straight line suspension stability .