Non-steerable Auxiliary Lift Axle
Systems
SUBJECT: Operation and Preventive
Maintenance Procedures
LIT NO: OM-H757
DATE: September 2018 REVISION: C
TABLE OF CONTENTS
Section 1

Introduction
Recording Your Model(s) / Serial Number(s). . . . . . 2

Section 2

Product Description
Identifying your Lift Axle Suspension(s). . . . . . . . . . 3
Axle Tag Identification. . . . . . . . . . . . . . . . . . . . . . . 3
Non-steerable Models. . . . . . . . . . . . . . . . . . . . . . . 4

Section 3

Important Safety Notice . . . . . . . . . . . . . . . . 6

Section 4

Lift Axle Operation
Controlling Inside or Outside-Mounted Lift Axle
Air Control System Kits . . . . . . . . . . . . . . . . . . 10
Raising your Lift Axle . . . . . . . . . . . . . . . . . . . . . . 10
Lowering your Lift Axle . . . . . . . . . . . . . . . . . . . . . 10

Section 5

Preventive Maintenance
Daily / Pre-trip Operator Inspection. . . . . . . . . . . . 11
General Inspection. . . . . . . . . . . . . . . . . . . . . . . . 11
Hendrickson Recommended
Maintenance Intervals. . . . . . . . . . . . . . . . . . . 11
Hendrickson Recommended
Lubrication Specifications. . . . . . . . . . . . . . . . 11

Section 6

Air Pressure Load Information
How to Measure Ride Air Spring
Extension and Axle Lift. . . . . . . . . . . . . . . . . . . 12
Air Pressure Load Charts. . . . . . . . . . . . . . . . . . . . 13

Section 7

Torque Specifications. . . . . . . . . . . . . . . . . . 15

Section 8

Troubleshooting Guide. . . . . . . . . . . . . . . . 16

Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
SECTION 1

Introduction
This publication is intended to acquaint and assist maintenance personnel in the identification and operation of and preventive maintenance for Hendrickson non-steerable auxiliary lift axle suspension systems.
Refer to the current versions of Hendrickson product-specific technical procedures, including Publication
No. H621, for additional installation, service, repair, and rebuild instructions for such products.
NOTE

Use only Hendrickson Genuine Parts for servicing this suspension system.
It is important to read and understand this entire publication prior to operating or performing any maintenance of the product. The information in this publication contains product images, safety information,
product specifications, features and proper maintenance and operating instructions of Hendrickson
non‑steerable auxiliary lift axles.
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
1-800-660-2829 (toll-free U.S. and Canada), 1-740-929-5600 (Outside U.S. and Canada), or email:
liftaxle‌@‌hendrickson‑intl.com.
The latest revision of this publication is also available online at
www.hendrickson-intl.com.

Recording Your Model(s) / Serial Number(s)
Please utilize Table 1-1 to record the Model(s) and Serial Number(s) of your suspensions / axles for future
reference to help identify such equipment when contacting Hendrickson Specialty Products – Auxiliary Lift
Axle Systems. This information is necessary for warranty and / or customer service needs. To locate the
Model and Serial Number information refer to Figure 2-1.
NOTE

Refer to the current version of Hendrickson Publication No. H624 for information on the limited warranty
coverage and warranty claims process for Hendrickson auxiliary lift axle suspension systems.

TABLE 1-1

MODEL

SERIAL NUMBER

1.
2.
3.
4.
5.
6.
NOTES

Introduction

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Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
SECTION 2

Product Description
IDENTIFYING YOUR LIFT AXLE SUSPENSION(S)
NOTE

All Hendrickson Auxiliary Lift Axles are manufactured with a serial number plate to help in identification, see
Figure 2-1.
When identifying your Hendrickson Auxiliary Lift Axle visually, see Figures 2-2 to 2-7 to compare with your
suspension.

AXLE TAG IDENTIFICATION
The Serial Number Label shown in Figure 2-1 is stainless steel label attached to the body of the suspension
system. The label contains the model and serial number unique to that particular suspension system. These
two numbers are important to use when contacting Hendrickson for customer service, replacement parts
and warranty.
FIGURE 2-1 Serial Number Label

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Product Description

Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
NON-STEERABLE MODELS
Hendrickson’s line of non-steerable lift axles offer the rugged reliability expected from Hendrickson in
both truck and trailer applications. The non-steerable line is engineered for rugged on- and off‑highway
applications accommodating a wide range of ride heights. The Hendrickson product line includes the
popular COMPOSILITE™ FX and TOUGHLIFT™ FM and TOUGHLIFT™ FR with capacities ranging from 13,500
to 25,000 pounds.
FIGURE 2-2

COMPOSILITE™ FXT | TRUCK
The COMPOSILITE FXT, for non-steerable truck applications is designed
with a lightweight fabricated axle that accommodates both pusher and tag
applications. The COMPOSILITE FXT includes components that are common
with the SC steerable lift axle family to ease replacement and maintenance
procedures on the same vehicle.
Available in 8K and 10K and 13.5K pound capacities.

FIGURE 2-3

COMPOSILITE™ FXW • FXB | TRAILER
The COMPOSILITE FXW and FXB non-steerable trailer applications are designed
with a lightweight fabricated axle that accommodates both pusher and tag
applications. The FXW and FXB include components that are common with
the COMPOSILITE SC steerable lift axle family to ease replacement and
maintenance procedures on the same vehicle. Trailer applications of the FX13
are available in weld-on and bolt-on configurations.
Available in 13.5K pound capacity. Available in weld-on (FXW) or
bolt-on (FXB).
FIGURE 2-4

COMPOSILITE™ FXO | ROLL OFF TRUCK
The COMPOSILITE FX0 for non-steerable roll-off truck applications is designed
with a lightweight fabricated axle accommodating capacities up to 13,500
pounds.The FXO includes components that are common with the COMPOSILITE
SCO13 steerable lift axle to ease replacement and maintenance procedures on
the same vehicle. Its scalloped hangers, inbound-positioned ride springs, and
parallelogram components aid in the clearance around roll-off cylinders.
Available in capacities up to 13.5K pounds.

Product Description

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Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
FIGURE 2-5

TOUGHLIFT™ FMT | TRUCK
The TOUGHLIFT FMT is engineered for rugged on- and off-highway truck
applications accommodating capacities up to 25,000 pounds in both pusher
and tag axle configurations. The integration of Hendrickson’s TRI-FUNCTIONAL®
bushing helps absorb brake and acceleration forces while providing superior
roll-control. The QUIK-ALIGN feature simplifies the alignment process by
eliminating welding of the alignment collar.
Available in capacities up to 25K pounds.

FIGURE 2-6

TOUGHLIFT™ FMW • FMB | TRAILER
The TOUGHLIFT FMW and FMB are engineered for rugged on- and off‑highway
trailer applications accommodating capacities up to 22,000 pounds in
both weld-on and bolt-on configurations. The integration of Hendrickson’s
TRI-FUNCTIONAL bushing helps absorb brake and acceleration forces while
providing superior roll-control. The QUIK‑ALIGN feature simplifies the alignment
process by eliminating welding of the alignment collar.
Available in capacities up to 22K pounds. Available in weld-on (FMW) or
bolt-on (FMB).
FIGURE 2-7

TOUGHLIFT™ FRT | TRUCK
The TOUGHLIFT FRT is designed to provide high lifting capability, accommodate
various ride heights, and facilitate easier installation in truck applications. The
axle is positioned at the rear of the suspension, allowing for greater clearance
of the vehicle undercarriage. Available in short- and medium-beam versions to
accommodate a variety of frame packaging dimensions with a capacity up to
13,000 pounds.
Available in 13K pound capacity.

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Product Description

Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
SECTION 3

Important Safety Notice
Proper installation, maintenance, service, and repair is important for 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.
All safety related information should be read carefully to help prevent personal injury and to assure that
proper methods are used. Improper installation, maintenance, service or repair may damage the vehicle,
cause personal injury, render it unsafe in operation, or void manufacturer’s warranty.
Failure to follow the safety precautions in this manual can 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 installation, 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 to service personnel, or possibility of improper service methods which may damage the vehicle or
render it unsafe.
This is the safety alert symbol. It is used to alert you to potential personal injury hazards. Obey

all safety messages that follow 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.
INDICATES AN IMMINENTLY HAZARDOUS SITUATION, WHICH IF NOT AVOIDED, WILL RESULT IN SERIOUS INJURY
OR DEATH.
INDICATES A POTENTIAL HAZARDOUS SITUATION WHICH, IF NOT AVOIDED, CAN RESULT IN SERIOUS INJURY OR
DEATH.
INDICATES A POTENTIAL HAZARDOUS 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

A helpful suggestion that will make the servicing being performed a little easier and/or faster.
The torque symbol alerts you to tighten fasteners to a specified torque value. Refer to Torque Specifications
Section of this publication.

Important Safety Notice

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Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
■■

SAFETY PRECAUTIONS

LIFT AXLE RAPID MOVEMENT
LIFT AXLE RAPID MOVEMENT CAN CAUSE SEVERE PERSONAL INJURY OR DEATH.
IF LIFT AXLE IS OPERATED BY AN AUTOMATIC OR SEMI‑AUTOMATIC LIFT AXLE CONTROL SYSTEM, SUCH SYSTEM
MAY CAUSE LIFT AXLE TO AUTOMATICALLY RAISE OR LOWER UNDER DIFFERENT CONDITIONS.
LIFT AXLE ACTIVATION AND MOVEMENT MAY VARY DEPENDING ON THE BRAND, CONFIGURATION, AND
OPERATING CONDITION OF THE LIFT AXLE CONTROL SYSTEM AND / OR OTHER FACTORS. READ, UNDERSTAND,
AND COMPLY WITH ALL APPLICABLE OPERATING INSTRUCTIONS AND SAFETY INFORMATION PROVIDED BY THE
LIFT AXLE CONTROL SYSTEM MANUFACTURER AND VEHICLE MANUFACTURER.
ENSURE ALL PERSONNEL ARE CLEAR OF LIFT AXLE BEFORE AND DURING VEHICLE LOADING AND LIFT AXLE
ACTIVATION UP OR DOWN.

LIFT AXLE ACTIVATION
DO NOT LOWER LIFT AXLE WHILE THE VEHICLE IS MOVING IN REVERSE OR TRAVELING AT MORE THAN 15 MPH.
FAILURE TO DO SO CAN CAUSE COMPONENT DAMAGE.

NAVIGATING A 90 DEGREE CURVE OR TURN
TO MINIMIZE PREMATURE TIRE WEAR OR POSSIBLE DAMAGE TO LIFT AXLE COMPONENTS, THE LIFT AXLE MAY BE
RAISED TO THE UP POSITION PRIOR TO NAVIGATING A 90 DEGREE OR TIGHTER CURVE OR TURN. COMPLY WITH
ALL FEDERAL, STATE / PROVINCIAL AND / OR LOCAL WEIGHT, DIMENSION AND CONFIGURATION REGULATIONS
UNDER LOADED AND UNLOADED CONDITIONS.

LOAD CAPACITY
ADHERE TO THE PUBLISHED CAPACITY RATINGS FOR THE AUXILIARY AXLE. ADD-ON AXLE ATTACHMENTS (I.E.
SLIDING FIFTH WHEELS) AND OTHER LOAD TRANSFERRING DEVICES CAN INCREASE THE AUXILIARY AXLE
LOAD ABOVE THE RATED AND APPROVED CAPACITIES WHICH CAN RESULT IN FAILURE AND ADVERSE VEHICLE
HANDLING, POSSIBLY CAUSING PERSONAL INJURY OR PROPERTY DAMAGE.

DAILY/PRE-TRIP OPERATOR INSPECTION
DAILY (AND BEFORE EACH TRIP) INSPECT ALL LIFT AXLE COMPONENTS FOR PROPER OPERATING CONDITION
AND PROPER INSTALLATION TO THE TRUCK / TRAILER FRAME. THIS ESSENTIAL DAILY / PRE-TRIP OPERATOR
INSPECTION MUST ALSO INCLUDE A VISUAL INSPECTION OF ALL WHEEL SEALS AND GASKETS FOR LEAKS,
A VERIFICATION OF PROPER OIL LEVEL IN THE HUBS (IF APPLICABLE), INSPECTION OF ALL LIFT AND RIDE
AIR‑SPRINGS FOR WEAR, AND INSPECTION OF ALL TIRES FOR PROPER INFLATION AN ABNORMAL WEAR
PATTERNS. IDENTIFY AND REPAIR / REPLACE ANY LOOSE, DAMAGED OR IMPROPERLY INSTALLED COMPONENTS.
REFER TO THE CURRENT VERSION OF HENDRICKSON PUBLICATION NO. TP-H621 FOR ADDITIONAL SERVICE,
REPAIR, AND REBUILD INSTRUCTIONS.

REPAIR AND RECONDITIONING
THE REPAIR OR RECONDITIONING OF AUXILIARY AXLE COMPONENTS THAT ARE BENT, DAMAGED OR OUT
OF SPECIFICATION IS NOT ALLOWED. ANY AXLE COMPONENTS FOUND TO BE DAMAGED OR OUT OF
SPECIFICATION, MUST BE REPLACED. AXLE COMPONENTS CANNOT BE BENT, WELDED, HEATED, OR REPAIRED
WITHOUT REDUCING THE STRENGTH OR LIFE OF THE COMPONENT. FAILURE TO FOLLOW THESE GUIDELINES
CAN CAUSE ADVERSE VEHICLE HANDLING, POSSIBLE PERSONAL INJURY, DEATH, OR PROPERTY DAMAGE AND
WILL VOID APPLICABLE WARRANTIES.

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

PROCEDURES AND TOOLS
A MECHANIC USING A SERVICE PROCEDURE OR TOOL, THAT 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 ASSUME ALL RISKS OF POTENTIAL PERSONAL INJURY OR DAMAGE TO EQUIPMENT INVOLVED.

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Important Safety Notice

Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
FASTENERS
DISCARD USED FASTENERS. ALWAYS USE NEW FASTENERS TO COMPLETE A REPAIR. FAILURE TO DO SO
COULD RESULT IN FAILURE OF THE PART OR MATING COMPONENTS, ADVERSE VEHICLE HANDLING, PERSONAL
INJURY, OR PROPERTY DAMAGE.
LOOSE OR OVER-TORQUED FASTENERS CAN CAUSE COMPONENT DAMAGE, ADVERSE VEHICLE HANDLING,
PROPERTY DAMAGE, OR SEVERE PERSONAL INJURY. MAINTAIN CORRECT TORQUE VALUE AT ALL TIMES. CHECK
TORQUE VALUES ON A REGULAR BASIS AS SPECIFIED, USING A REGULARLY CALIBRATED TORQUE WRENCH.
TORQUE VALUES SPECIFIED IN THIS TECHNICAL PUBLICATION ARE FOR HENDRICKSON SUPPLIED FASTENERS
ONLY. IF NON‑HENDRICKSON FASTENERS ARE USED, FOLLOW TORQUE SPECIFICATIONS LISTED IN THE VEHICLE
MANUFACTURER’S SERVICE MANUAL.

MODIFYING 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, ADVERSE VEHICLE HANDLING, POSSIBLE PERSONAL
INJURY OR PROPERTY DAMAGE, AND WILL VOID APPLICABLE WARRANTIES. USE ONLY HENDRICKSONAUTHORIZED REPLACEMENT PARTS.
THE VEHICLE MANUFACTURER SHOULD BE CONSULTED BEFORE MAKING ANY CHANGES TO THE VEHICLE’S
FRAME. TYPICALLY, CUTTING OR ALTERING THE VEHICLE’S FRAME OR SIDE RAIL IS NOT PERMITTED AND MAY
AFFECT THE MANUFACTURER’S WARRANTY COVERAGE.
ANY INSTALLATION DEVIATIONS MUST BE APPROVED IN WRITING BY HENDRICKSON’S PRODUCT ENGINEERING
DEPARTMENT. FAILURE TO COMPLY WITH ANY OF THE ABOVE WILL VOID APPLICABLE WARRANTIES.

DAMAGED AXLE COMPONENTS
IF A VEHICLE EQUIPPED WITH A HENDRICKSON AUXILIARY AXLE IS INVOLVED IN A CRASH, A THOROUGH
INSPECTION OF THE AXLE MUST BE PERFORMED NOTING THE CONDITION OF THE AXLE BEAM, KINGPINS,
AND KNUCKLE ASSEMBLIES, INCLUDING THE AREAS OF AXLE-TO-KINGPIN INTERFACE, FOR ANY DAMAGE,
GAPS, KINGPIN MOVEMENT OR PLAY. IF ANY COMPONENT APPEARS DAMAGED, OR THE KINGPINS APPEAR TO
CONTAIN ANY DAMAGE, GAPS, MOVEMENT OR PLAY, THE COMPLETE AXLE ASSEMBLY MUST BE REPLACED.
IN ADDITION, IN THE EVENT A CRASH RESULTS IN EXCESSIVE SIDE LOAD DAMAGE TO ADJACENT PARTS, SUCH
AS A BENT WHEEL, HUB, OR SPINDLE, IT IS STRONGLY RECOMMENDED TO REPLACE SUCH ADJACENT PARTS
AND THE COMPLETE AXLE ASSEMBLY.
CONTACT HENDRICKSON TECHNICAL SERVICES DEPARTMENT WITH ANY QUESTIONS. FAILURE TO REPLACE
ANY DAMAGED COMPONENTS CAN CAUSE ADVERSE VEHICLE HANDLING, POSSIBLE PERSONAL INJURY,
DEATH, OR PROPERTY DAMAGE AND WILL VOID ANY APPLICABLE WARRANTIES.

LIFT AXLE CAMBER
UNAUTHORIZED WELDING OR MODIFICATIONS CAN CAUSE CRACKS OR OTHER LIFT AXLE STRUCTURAL DAMAGE
AND RESULT IN ADVERSE VEHICLE HANDLING, SEVERE PERSONAL INJURY OR DEATH. DO NOT BEND, WELD
OR MODIFY AXLE WITHOUT AUTHORIZATION FROM HENDRICKSON. AXLE CAMBER IS NOT ADJUSTABLE. DO
NOT CHANGE THE AXLE CAMBER ANGLE OR BEND THE AXLE BEAM. BENDING THE AXLE BEAM TO CHANGE
THE CAMBER ANGLE CAN DAMAGE THE AXLE AND REDUCE AXLE STRENGTH, CAN CAUSE ADVERSE VEHICLE
HANDLING, POSSIBLY CAUSING PERSONAL INJURY OR PROPERTY DAMAGE AND WILL VOID APPLICABLE
WARRANTIES.

IMPROPER JACKING METHOD
IMPROPER JACKING METHOD CAN CAUSE STRUCTURAL DAMAGE AND RESULT IN ADVERSE VEHICLE HANDLING,
SEVERE PERSONAL INJURY OR DEATH. DO NOT USE AXLE BEAM OUTBOARD OF AXLE SPRING SEATS. REFER TO
VEHICLE MANUFACTURER FOR PROPER JACKING INSTRUCTIONS.

Important Safety Notice

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Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
SUPPORT THE VEHICLE PRIOR TO SERVICING
PLACE THE VEHICLE ON A LEVEL FLOOR AND CHOCK THE WHEELS TO HELP PREVENT THE VEHICLE FROM
MOVING. PRIOR TO SERVICING A VEHICLE IN THE RAISED POSITION, PROPERLY SUPPORT THE VEHICLE WITH
SAFETY STANDS. DO NOT WORK AROUND OR UNDER A RAISED VEHICLE SUPPORTED ONLY WITH FLOOR
JACKS OR OTHER LIFTING DEVICES, FAILURE TO DO SO CAN CAUSE DEATH, PERSONAL INJURY OR DAMAGE TO
COMPONENTS.

SUPPORT THE LIFT AXLE PRIOR TO SERVICING
PLACE THE VEHICLE ON A LEVEL FLOOR AND CHOCK THE WHEELS TO HELP PREVENT THE VEHICLE FROM
MOVING. PRIOR TO SERVICING A LIFT AXLE IN THE RAISED POSITION, (1) PROPERLY SUPPORT THE LIFT AXLE
WITH SAFETY STANDS, AND (2) RELEASE ALL AIR PRESSURE IN THE LIFT AXLE AIR SPRINGS AND RIDE SPRINGS.
DO NOT WORK AROUND OR UNDER A RAISED LIFT AXLE SUPPORTED ONLY WITH FLOOR JACKS OR OTHER
LIFTING DEVICES, FAILURE TO DO SO CAN CAUSE DEATH, PERSONAL INJURY OR DAMAGE TO COMPONENTS.

AIR SPRINGS
AIR SPRING ASSEMBLIES MUST BE DEFLATED PRIOR TO LOOSENING ANY ADJACENT HARDWARE.
UNRESTRICTED AIR SPRING ASSEMBLIES CAN VIOLENTLY SHIFT. DO NOT INFLATE AIR SPRING ASSEMBLIES
WHEN THEY ARE UNRESTRICTED. AIR SPRING ASSEMBLIES MUST BE RESTRICTED BY SUSPENSION OR
OTHER ADEQUATE STRUCTURE. DO NOT INFLATE BEYOND PRESSURES RECOMMENDED BY AIR SPRING
MANUFACTURER. CONTACT HENDRICKSON TECHNICAL SERVICES FOR DETAILS. IMPROPER USE OR OVER
INFLATION MAY CAUSE AIR SPRING ASSEMBLIES TO BURST, CAUSING PROPERTY DAMAGE AND / OR SEVERE
PERSONAL INJURY.

AIR SPRINGS
EXHAUST ALL PRESSURE IN LIFT AXLE AIR SPRINGS AND VEHICLE AIR SYSTEM BEFORE WORKING ON OR
AROUND LIFT AXLE. FAILURE TO DO SO CAN CAUSE SEVERE PERSONAL INJURY OR DEATH.

AIR SPRINGS
PRIOR TO AND DURING DEFLATION AND INFLATION OF THE AIR SUSPENSION SYSTEM, ENSURE THAT ALL
PERSONNEL AND EQUIPMENT ARE CLEAR FROM UNDER THE VEHICLE AND AROUND THE SERVICE AREA, FAILURE
TO DO SO CAN CAUSE SEVERE PERSONAL INJURY, DEATH, OR PROPERTY DAMAGE.

AIR SPRINGS
INFLATE THE SUSPENSION SLOWLY AND MAKE SURE THE RUBBER BLADDER OF THE AIR SPRING INFLATES
UNIFORMLY AND IS NOT BINDING. FAILURE TO DO SO CAN CAUSE DAMAGE TO THE AIR SPRING AND / OR
MOUNTING BRACKETS AND WILL VOID APPLICABLE WARRANTIES.

OFF ROADWAY TOWING
HENDRICKSON DOES NOT RECOMMEND TOWING A VEHICLE BY THE AUXILIARY AXLE. DOING SO WILL DAMAGE
THE AXLE AND WILL VOID APPLICABLE WARRANTIES.

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:

1.
2.
3.
4.
5.

WEAR PROPER EYE PROTECTION.
WEAR CLOTHING THAT PROTECTS YOUR SKIN.
WORK IN A WELL VENTILATED AREA.
DO NOT USE GASOLINE OR SOLVENTS THAT CONTAIN GASOLINE. GASOLINE CAN EXPLODE.
HOT SOLUTION TANKS OR ALKALINE SOLUTIONS MUST BE USED CORRECTLY. FOLLOW THE
MANUFACTURER’S RECOMMENDED INSTRUCTIONS AND GUIDELINES CAREFULLY TO HELP PREVENT
PERSONAL ACCIDENT OR INJURY.

DO NOT USE HOT SOLUTION TANKS OR WATER AND ALKALINE SOLUTIONS TO CLEAN GROUND OR POLISHED
PARTS. DOING SO WILL CAUSE DAMAGE TO THE PARTS AND VOID APPLICABLE WARRANTIES.

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Important Safety Notice

Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
SECTION 4

Lift Axle Operation
CONTROLLING INSIDE OR OUTSIDE-MOUNTED LIFT AXLE
AIR CONTROL SYSTEM KITS
1. If vehicle is already running, please proceed to the appropriate section below.
2. Set parking brake of truck.
3. Turn your vehicle ignition to ON position.
4. Press ignition START switch and release when engine is started.
5. Allow the vehicle to idle until the vehicle’s air system pressure has reached compressor cut-out point,
(typically 120 psi).

RAISING YOUR LIFT AXLE
1. If the lift axle controls are mounted:
■■
■■

inside the vehicle cab – move the control panel mechanism (pull to lift) to the axle up position.
outside the vehicle cab – ensure vehicle is stopped and parking brake is set. Exit vehicle, go to and
open air control enclosure. Move the control panel mechanism to the axle up position.

2. Visually confirm that the lift axle is lifting.
NOTE

Air system pressure may drop during suspension lifting process.
3. Lift axle should be completely lifted when air system pressure returns to the air compressor cut‑out
point (typically 120 psi).

LOWERING YOUR LIFT AXLE
DO NOT LOWER LIFT AXLE WHILE VEHICLE IS MOVING IN REVERSE OR TRAVELLING MORE THAN 15 MPH. FAILURE
TO DO SO CAN CAUSE COMPONENT DAMAGE.

1. If the lift axle controls are mounted:
■■

■■

inside the vehicle cab – move the control panel mechanism (push to lower) to the axle down
position.
outside the vehicle cab – ensure the vehicle is stopped and parking brake is set. Exit vehicle, go
to and open air control enclosure. Move the control panel mechanism to the axle down position.

2. Using the regulator, adjust air system pressure on the gauge to appropriate air pressure for vehicle load
conditions, see Air Pressure Load Information Section of this publication.
NOTE

Air system pressure may drop during suspension lowering process.
3. Lift axle should be completely lowered and supporting pre-determined load when air system pressure
returns to the air compressor cut-out point (typically 120 psi).
NAVIGATING A 90 DEGREE CURVE OR TURN
TO MINIMIZE PREMATURE TIRE WEAR OR POSSIBLE DAMAGE TO LIFT AXLE COMPONENTS, THE LIFT AXLE MAY BE
RAISED TO THE UP POSITION PRIOR TO NAVIGATING A 90 DEGREE OR TIGHTER CURVE OR TURN. COMPLY WITH
ALL FEDERAL, STATE / PROVINCIAL AND / OR LOCAL WEIGHT, DIMENSION AND CONFIGURATION REGULATIONS
UNDER LOADED AND UNLOADED CONDITIONS.

Lift Axle Operation

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Owner’s Manual – Non-steerable Auxiliary Lift Axle Systems
SECTION 5

Preventive Maintenance
DAILY / PRE-TRIP OPERATOR INSPECTION
Daily (and before each trip) inspect all lift axle components for proper operating condition and proper
installation to the truck / trailer frame. This essential Daily / Pre-trip Operator Inspection must also include
a visual inspection of all wheel seals and gaskets for leaks, a verification of proper oil level in the hubs (if
applicable), inspection of all lift and ride air-springs for wear, and inspection of all tires for proper inflation
and abnormal wear patterns. Identify and repair / replace any loose, damaged or improperly installed components. Refer to the current version of Hendrickson Publication No. TP-H621 for additional service, repair,
and rebuild instructions.
NOTE

Replace any safety decals that are faded, torn, missing, illegible, or otherwise damaged. Contact
Hendrickson to order replacement labels.

GENERAL INSPECTION
Following appropriate inspection procedures is important to help ensure the proper maintenance and
operation of the suspension system and that component parts function to their highest efficiency.
■■

■■

Fasteners — Inspect for any loose or damaged fasteners on the entire lift axle suspension. Make sure
all fasteners are tightened to the specified torque. Refer to the Torque Specifications Section of this
publication if fasteners are supplied by Hendrickson. For non‑Hendrickson fasteners, refer to the vehicle
manufacturer. Use a calibrated torque wrench to check torque in a tightening direction. As soon as the
fastener starts to move, record the torque. Correct the torque if necessary. Replace any worn or damaged fasteners.
Air springs — Visually Inspect suspension for any debris rubbing against air springs or signs of chaffing. Clear debris and / or replace air springs with Hendrickson Genuine Parts as necessary.

HENDRICKSON RECOMMENDED MAINTENANCE INTERVALS
COMPONENT

INITIAL BREAK‑IN

Wheel Bearings
Brake Chamber
Wheel Seals

INTERVALS AFTER INITIAL BREAK‑IN

PROCEDURE

5,000 mi.

8,000 miles or every 2 months, whichever comes first