fHJTECHNICAL
®
PROCEDURE
HAULMAAX® Rear Suspension
SUBJECT: Service Instructions
LIT NO: 17730-244
DATE: November 2014
REVISION : F

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Section 1

Introduction ................... . .... 2

Section 2

Product Description ................. 2

Section 3

Important Safety Notice .... .......... 5

Section 4

Parts Lists . ............... .. . .. ..... 8

Section 5

Special Tools ................ . .. . .. 13

Section 6

Preventive Maintenance ............. 14
Inspection Intervals................... 14

Shock Absorbers (if equipped) .......... 38
Attermorket Shock Absorber Kit .......... 39

Component Inspection ........... ... . . 15
Longitudinal and Transverse Torque Rods . . 16

Equalizing Beam ..................... 41
Bar Pin End Bushing .. . ....... . ....... 45

Bolster Springs . .. ... .... .. . .. . ...... 16
Rebound Strap ...................... 17

Longitudinal Torque Rods . . .... ..... . ... 49
Transverse Torque Rods . . .............. 49

Load Spring - Progressive or Auxiliary ..... 18
Wear plate .. ....................... 18

Tapered and Straddle Mount
Torque Rod Bushings ...... ........... 50

Section 8

Component Replacement ........... 29
Fasteners .......................... 29
Outboard Frame Brocket ............... 29
Inboard Frame Bracket ................ 30
Saddle . ............... .. . ........ . 31
Load Spring - Progressive or Auxiliary .... . 34
Rebound Strop ...................... 35
Bolster Springs ...................... 36

Equalizing Beam End Connection . . .... .. 19
Axle Bracket . . . . .. .... .... . .. . ..... . 20
Bar Pin End Bushing .......... . . ...... 20
Bar Pin Shims . . . . . . . . . . . . . . . . . ..... 21
Shock Absorber Inspection (if equipped) ... 21
Section 7

Section 9

Torque Specifications .......... . . . . . 52

Section 1O Troubleshooting Guide ... ........... 54

Alignment & Adjustments .... . .. . ... 23
Load Spring Shim Evaluation ............ 23
Load Spring Shims Adjustment . .. ....... 24
Drive Axle Alignment Inspection Procedure . 24
Lateral Alignment .. ................. . 26
Bar Pin Alignment . .. .. ............... 26

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HAULMAAX® Rear Suspension
SECTION l

Introduction
This publication is intended to acquaint and assist maintenance personnel in the preventive
maintenance, service, repair and rebuild of the HAULMAAXI!> rear suspension system .

NOTE

Use on ly Genuine [HJ Hendrickson parts for servicing this suspension system.
It is important to read and understand the entire Technical Procedure publication prior to
performing any maintenance, service, repair. or rebuild of this product.The information in this
publication contai ns parts lists, safety information, product specifications. features. proper
maintenance, service, repair and rebuild instructions for the HAULMAAX Suspension .
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-mai l: techservices@hendrickson-intl.com.
The latest revision of this publication is also available online at
www.hendrickson-intl.com.

SECTION 2

Product Description
Advanced engineering design methods and experience gathered from mill ions of Hendrickson
suspensions created HAULMAAX, a rugged, yet lightweight rubber vocational rear suspension
that saves weight over competitive suspensions for greater payloads and route consolidation.
Suspension weight is reduced for greater payloads and improved durability through innovative
design, higher strength materials and advanced manufacturing methods. Proven with extensive
vehicle durability and laboratory testing, HAULMAAX delivers the reliability and quality you've
come to expect from Hendrickson, the leader in suspension technology.
The updated HAULMAAX spring system easily adjusts to the load for an enhanced combination
of em pty-ride quality and loaded stability. Most importantly, this innovative suspension significantly reduces wheel hop by eliminating the fixed pivot point found in the center bushings of
other walking-beam suspensions.
Extra wide bolster spring centers and a unique progressive load spring provide exceptional stability for demanding applications such as refuse, concrete mixers and dump.

lnlroduction

2

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HAULMAAX®Rear Suspension
FIGURE 2-1

Bar Pin
End Bushings

Bolster Springs

Major Components Include:

17730-244

•

Equalizing beam - Formed and rabatically-welded equalizing beam provides a narrow
profile for weight savings, distributes load equally between both axles for improved traction,
lowers the center of gravity to increase stability, and establishes a solid axle connection for
improved handling.The center bushing is also eliminated for reduced maintenance.

•

Bar pin end connection - Rugged axle connection extends bushing life, and allows easy
axle alignment and serviceability.

•

Saddle and frame brackets - Lightweight, modular design simplifies installation.

•

ULTRA ROD®torque rods - Improve cornering by controlling lateral forces.Transverse rods
ensure maximum lateral axle control and straight line suspension stability. Longitudinal rods
engineered lo optimize resistance to wind up during occeleration and braking.

•

Progressive Load Spring - Newly designed to always engage for smoother ride and
additional stability, and eli minate shim adjustments for lower maintenance (for most
applications).

•

Premium rubber bolster springs - The unique design works with the progressive load
spring to deliver unparalleled empty ride quality and loaded stability.

•

Optional shock absorbers - Provide additional driver comfor1. Required for tractor and
logging applications. Available as production or attermarket options.

3

Product Description

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HAULMAAX® Rear Suspension
HAULMAAX SPECIFICATIONS
HMX 400
Installed Weight1 (54" axle spacing)

HMX 460
861 lbs
46.000 lbs
80.000 lbs
190.000 lbs
60.000 lbs
17 inch

Diagonal Articulation•

855 lbs
40.000 lbs
73.000 lbs
160.000 lbs
55.000 lbs
17 inch

Litt Axles

Approved

Approved

Ride Heights (loaded)'
Axle Spacing•

9.5". l 0.5". 11.5".
13.25". 15.5"
52". 54", 60". 72.5"

9.5". l 0.5". 11.5".
13.25". 15 .5". 18.5"
52". 54". 60". 72.5"

Shock Absorber Applications'

Tractors. Logging

Tractors. Logging

Suspension Roting
GWJ Approval'

GCW Approval
Site Travel Roting3

Hendrickson approves lhe use of HAULMAAX in the following vocolionol lruck opplicol1ons.dump. concrele mixer. refuse.
logging. crone I boom. platform ond lire I rescue. All such opplicolions musl comply w1lh opplicoble Hendrickson spec1l1cot1ons ond musl also be approved by lhe respecl1ve vehicle monufocturer with lhe vehicle in 1ls original. os-buill
conf1gurolion.Conlocl Hendrickson ond lhe respechve vehicle monufoclurer for approval of odd1t1onol opplicol1ons.

Product Descriplion

1.

lnslolled weighl includes complele suspension. lorque rods. axle brockels ond lrome brockels; odd 31 pounds for
shock absorbers.

2.

Conloct Hendrickson for oppl1cotions thol moy exceed GWJ approval rolings.

3.

Sile travel roting - operolors using vehicles equipped with littoble pusher or log oxles musl nol exceed published
rolings. Rolings are l1miled to no more lhan five percenl of vehicle operation ol speed not lo exceed five mph. Liflable
pusher or log axles should only be raised (or unloaded) to improve vehicle maneuverability in off-road use or when
vehicle 1s empty.Sile lrovel rolings ore consistenl wilh published axle manufoclurer's limilations.Axle ond suspension
site travel specifications must not be exceeded.

4.

Suspension articulation may exceed vehicle's capability and may be limited by vehicle manufacturer. vehicle manufacturer installed axle stops may restrict suspension's articulation.

5.

HAULMAAX ride height meosuremenls ore laken from lhe centerline ol the axle to the boltom of lhe lruck lrome.

6.

Contacl Hendrickson for ova1lab11ity of beam lengths.

7

Shock absorbers ore required in lraclor ond logging opplicolions. Ride ond trocl1on moy be improved 1n olher opplicolions wilh shock absorbers. Ride performance con be subjective ond moy be dependent on mony factors beyond the
suspension design such os cob suspension. rood condilions. body I auxiliary equipment. frame specif1colions. elc
Conloct Hendrickson or your lruck monufocturer I dealer for further informolion.

4

17730-244

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HAULMAAX® Rear Suspension

SECTION 3

Important Safety Notice
Proper maintenance. service and repair are important to the reliable operation of the suspension .The procedures recommended by Hendrickson and described in this technical publication
are methods of performing such maintenance. service and repair.
The warnings and cautions should be read carefully ta help prevent personal injury and to
assure that proper methods are used. Improper maintenance. service or repair may damage the
vehicle. cause personal injury. render the vehicle unsafe in operation, or void the manufacturer's
warranty.
Fai lure to follow the safety precautions in this manual con result in personal injury and/or
property damage. Carefully read and understand all safety related information within this publication. on all decals and in all such materials provided by the vehicle manufacturer before
conducting any maintenance. service or repair.

• EXPLANATION OF SIGNAL WORDS
Hazard "Signal Words" (Danger-Warning-Caution) appear in various locations throughout this
publication. Information accented by one of these signal words must be observed to help minimize the risk of personal injury ta service personnel, or possibility of improper service methods
which may damage the vehicle or render it unsafe.

m

This is the safety alert symbol. It is used to alert you to potential personal injury
hazards. Obey all safety messages that fol low this symbol to avoid possible injury
or death.
Additional 'Notes' or 'Service Hints' are utilized to emphasize areas of procedural importance
and provide suggestions for ease of repair.The following definitions indicate the use of these
signal words as they appear throughout the publication.

A

DANGER

INDICATES AN IMMINENTLY HAZARDOUS SITUATION. WHICH. IF NOTAVOIDED. WILL RESULT IN
SERIOUS INJURY OR DEATH.

A

WARNING

INDICATES A POTENTIALHAZARDOUSSITUATIONWHICH. IF NOT AVOIDED. CAN RESULTIN DEATH OR
SERIOUS INJURY.

A

CAUTION

INDICATES A POTENTIALHAZARDOUS SITUATION WHICH, IF NOT AVOIDED. MAY RESULT IN MINOR OR
MODERATE INJURY.

NOTE

An operating procedure. practice condition, etc., which is essential to emphasize.

SERVICE HINT

Ahelpful suggestion that will make the service being performed a little easier and/or faster.
Also note that particular service operations may require the use of special tools designed for
specific purposes. These special tools can be found in the Special Tools Section of this publication.
The torque symbol alerts you to tighten fasteners to a specified torque value. Refer to Torque
Specifications Section of this publication.

17730-244

5

lmportont Sofety Notice

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HAULMAAX® Rear Suspension
• SAFETY PRECAUTIONS

A

WARNING

FASTENERS
DISCARD USED FASTENERS. ALWAYS USE NEW FASTENERS TO COMPLETE A REPAIR. FAILURE TO
DO SO COULD RESULT IN FAILURE OFTHE PART OR MATING PARTS. LOSS OF VEHICLE CONTROL.
PERSONAL INJURY. OR PROPERTY DAMAGE.
LOOSE OR OVER TORQUED FASTENERS CAN CAUSE COMPONENT DAMAGE. LOSS OF VEHICLE
CONTROL. PROPERTY DAMAGE. OR SEVERE PERSONAL INJURY. MAINTAIN CORRECT TORQUE
VALUES AT ALL TIMES. CHECK TORQUE VALUES ON A REGULAR BASIS AS SPECIFIED. USING A
TORQUE WRENCH THAT IS REGULARLY CALIBRATED. TORQUE VALUES SPECIFIED INTHIS TECHNICAL
PUBLICATION ARE FOR HENDRICKSON SUPPLIED FASTENERS ON LY. IF NON HENDRICKSON
FASTENERS ARE USED. FOLLOW TORQUE SPECIFICATION LISTED IN THE VEHICLE MANUFACTURER'S
SERVICE MANUAL.

A

WARNING

A

WARNING

A WARNING

LOAD CAPACITY
ADHERE TO THE PUBLISHED CAPACITY RATINGS FOR THE SUSPENSION.ADD-ON AXLE ATTACHMENTS
AND OTHER LOAD TRANSFERRING DEVICES CAN INCREASE THE SUSPENSION LOAD ABOVE ITS
RATED AND APPROVED CAPACITIES, WHICH CAN RESULT IN COMPONENT DAMAGE AND LOSS OF
VEHICLE CONTROL. POSSIBLY CAUSING PERSONAL INJURY OR PROPERTY DAMAGE.
MODI FYING COMPONENTS
DO NOT MODIFY OR REWORK PARTS WITHOUT AUTHORIZATION FROM HENDRICKSON. DO NOT
SUBSTITUTE REPLACEMENT COMPONENTS NOT AUTHORIZED BY HENDRICKSON. USE OF MODIFIED.
REWORKED. SUBSTITUTE OR REPLACEMENT PARTS NOT AUTHORIZED BY HENDRICKSON MAY
NOT MEET HENDRICKSON'S SPECIFICATIONS, AND CAN RESULT IN FAILURE OF THE PART, LOSS
OF VEHICLE CONTROL, POSSIBLE PERSONAL INJURY OR PROPERTY DAMAGE, AND WILL VOID
WARRANTY. USE ONLY HENDRICKSON AUTHORIZED REPLACEMENT PARTS.
TORCH/WELDING
DO NOT USE A CUTTING TORCH TO REMOVE ANY FASTENERS. THE USE OF HEAT ON SUSPENSION
COMPONENTS WILL ADVERSELY AFFECT THE STRENGTH OF THESE PARTS.ACOMPONENT DAMAGED
IN THIS MANNER CAN RESULT IN THE LOSS OF VEHICLE CONTROL AND POSSIBLE PERSONAL INJURY
OR PROPERTY DAMAGE.
EXERCISE EXTREME CARE WHEN HANDLING OR PERFORMING MAINTENANCE INTHE AREA OF THE
EQUALIZING BEAM . DO NOT CONNECT ARC WELDING GROUND LINE TO THE EQUALIZING BEAM. DO
NOT STRIKE AN ARC WITH THE ELECTRODE ON THE EQUALIZING BEAM AND AXLE. DO NOT USE HEAT
NEAR THE EQUALIZING BEAM ASSEMBLY. DO NOT NICK OR GOUGE THE EQUALIZING BEAM. SUCH
IMPROPER ACTIONS CAN DAMAGE THE EQUALIZING BEAM ASSEMBLY, AND CAN CAUSE LOSS OF
VEHICLE CONTROL AND POSSIBLE PERSONAL INJURY OR PROPERTY DAMAGE.

A WARNING

TRANSVERSE RODS
THE HAULMAAX SUSPENSION INCORPORATES TRANSVERSE RODS FOR VEHICLESTABILITY. IFTHESE
COMPONENTS ARE DISCONNECTED OR ARE NON-FUNCTIONAL THE VEHICLE SHOULD NOT BE
OPERATED. FAILURE TO DO SO CAN RESULT IN ADVERSE VEHICLE HANDLING AND POSSIBLE TIRE
CONTACTWITH THEFRAME. OPERATING A VEHICLE WITH NON-FUNCTIONAL TRANSVERSE TORQUE
RODS CAN RESULT IN LOSS OF VEHICLE CONTROL SEVERE PERSONAL INJURY. AND PREMATURE
COMPONENT DAMAGE.

A

PERSONAL PROTECTIVE EQUIPMENT

WARNING

Important Safely Nallce

ALWAYS WEAR PROPER EYE PROTECTION AND OTHER REQUIRED PERSONAL PROTECTIVE
EQUIPMENT TO HELP PREVENT PERSONAL INJURY WHEN PERFORMING VEHICLE MAINTENANCE,
REPAIR OR SERVICE.

6

17730-244

HAULMAAX®Rear Suspension
PROCEDURES AND TOOLS
A TECHNICIAN USING A SERVICE PROCEDURE OR TOOL WHICH HAS NOT BEEN RECOMMENDED
BY HENDRICKSON MUST FIRST SATISFY HIMSELF THAT NEITHER HIS SAFETY NOR THE VEHICLE'S
SAFETY WILL BE JEOPARDIZED BY THE METHOD OR TOOL SELECTED. INDIVIDUALS DEVIATING IN
ANY MANNER FROM THE INSTRUCTIONS PROVIDED WILL ASSUME ALL RISKS OF CONSEQUENTIAL
PERSONAL INJURY OR DAMAGE TO EQUIPMENT INVOLVED.

A

CAUTION

A

WARNING

SUPPORTTHE VEHICLE PRIOR TO SERVICING
DO NOT ATANY TIME WORK AROUND OR UNDER AVEHICLE SUPPORTED ONLY ON LIFTI NG DEVICES.
THE VEHICLE MUST BE SECURELY CHOCKED AND SUPPORTED ON RIGID STANDS OF SUFFICIENT
STRENGTH BEFORE WORK MAY COMMENCE. FAILURE TO DO SO CAN CAUSE PERSONAL INJURY OR
DAMAGE TO EQUIPMENT.

A

WARNING

LOAD SPRING SHIM
AT LEAST ONE LOAD SPRING SHIM MUST BE EQUIPPED ON EACH SIDE OF THE HAULMAAX
SUSPENSION . FAILURE TO DO SO CAN CAUSE PREMATURE COMPONENTWEAR, EQUALIZING BEAM
MISALIGNMENT. LOSS OF VEHICLE CONTROL AND POSSIBLE PERSONAL INJURY OR PROPERTY
DAMAGE.

A

CAUTION

IMPROPER VEHICLE LIFT OR SUPPORT METHOD
IMPROPER VEHICLE LIFT OR SUPPORT METHOD CAN CAUSE DAMAGE TO HAULMAAX REAR
SUSPENSION BOLSTER SPRINGS, AND CAN VOID ANY WARRANTY COVERAGE . DO NOT LIFT
OR SUPPORT THE VEHICLE AT ONLY ONE OF THE TWO REAR DRIVE AXLES. WHEN LIFTING OR
SUPPORTING TH EVEHICLE USING THE DRIVEAXLES. ENSURE BOTH DRIVE AXLES ARE LIFTED AND
SUPPORTED TOGETHER. READ, UNDERSTAND AND COMPLY WITH ANY ADDI TIONAL VEHICLE LIFT
AND SUPPORT INSTRUCTIONS PROVIDED BY THE VEHICLE MANUFACTURER OR LIFT EQUIPMENT
MANUFACTURER.

A

WARNING

PARTS CLEANING
SOLVENT CLEANERS CAN BE FLAMMABLE, POISONOUS, AND CAUSE BURNS. TO HELP AVOID
SERIOUS PERSONAL INJURY. CAREFULLY FOLLOW THE MANUFACTURER'S PRODUCT INSTRUCTIONS
AND GUIDELINES AND THE FOLLOWING PROCEDURES:
l . WEARPROPEREYE PROTECTION.
2. WEARCLOTHING THAT PROTECTS YOUR SKIN .