Technical
Procedure
Hendrickson Trailer
Standard Service Wheel End
SUBJECT:Wheel-end Maintenance Procedures

LIT NO: L496
DATE: August 2012
REVISION: G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Table of Contents
Conventions Applied in this Document�� 3
Explanation of Signal Words�� 3
Links�� 3
General Service Notes�� 3
During Service:�� 3
Important Safety Notices�� 3
Contacting Hendrickson�� 5
Relative Literature�� 5
Preparing Trailer for Service�� 6
Hendrickson Wheel-end Types�� 7
Hendrickson Standard Service�� 7
Hendrickson Extended Service™ (HXS®)�� 7
Introduction�� 8
ADB Hub/Rotor�� 8
Tools Required�� 9
Inspection�� 9
Checking for Seal Leaks�� 10
Checking for Smooth Rotation�� 10
Checking End Play�� 11
Removing and Installing Hub�� 12
Hub Removal�� 12
Spindle Preparation�� 14
Prepare Hub for Install�� 14
Assemble Hub�� 14
Install Spindle nut�� 17
Install Hubcap�� 20
Hub Lubrication�� 20
Completing Installation�� 21
Approximate Hub Lube Capacity�� 21
Hub SF Grease Dam�� 21
Torque Values�� 23
Wheel Stud Removal / Installation Procedure�� 24
Stud Removal�� 24
Stud Installation�� 25
Brake Drum And Wheel Assembly�� 26
Assembly Procedures�� 27
2
L496 G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Conventions Applied in this
Document
General Service Notes
Important: Special attention should be paid to the
information included in Explanation
of Signal Words.
This section explains the techniques used in this
document to convey important information, safety
issues, how to contact Hendrickson and how to apply
hyperlinks.
Before you begin:
Read, understand and comply with:
• All instructions and procedures.
• All signal word (CAUTION, WARNING and
DANGER) statements to help avoid personal injury
or property damage.
• Company’s maintenance, service, installation and
diagnostic practices.
• Vehicle manufacturer’s safety instructions when
working on the vehicle.
• Vehicle manufacturer’s instructions for
recommended practices not described in this
manual.
• Local safety regulations.
Explanation of Signal Words
Hazard signal words (such as DANGER, WARNING
or CAUTION) appear in various locations throughout
this publication. Information accented by one of these
signal words must be observed at all times. Additional
notes are utilized to emphasize areas of procedural
importance and provide suggestions for ease of repair.
The following definitions comply with ANSI Z535.4
and indicate the use of safety signal words as they
appear throughout the publication.
DANGER:Indicates immediate hazards
which will result in severe
personal injury or death.
WARNING: Indicates hazards or unsafe practices
which could result in severe personal
injury or death.
During Service:
• Work must be carried out by trained personnel.
• Sudden release of tensioned springs (e.g. the
spring brake part of the brake chamber or the brake
return spring) may cause injury.
• Use recommended tools only.
• Before releasing trailer back into service, perform
operational checks and test the trailer to make sure
brakes are working correctly.
CAUTION: Indicates a hazardous situation
which, if not avoided, could result in
minor or moderate injury.
Notice:Indicates hazards or unsafe practices
which could result in damage to
machine or equipment.
Hendrickson reserves the right to make changes and
improvements to its products and publications at any
time. Consult the Hendrickson website
(www.hendrickson-intl.com) for the latest version of
this manual.
IMPORTANT: An operating procedure, practice
or condition that is essential to
emphasize.
Safety alert symbol used to indicate
a condition exists that may result in
personal injury or harm to individuals.
It must be applied to DANGER,
WARNING and CAUTION statements,
which emphasize severity.
Important Safety Notices
Proper maintenance, service and repair is important
to the reliable operation of the suspension system
and components. The procedures recommended by
Hendrickson and described in this publication are
methods of performing inspection, maintenance,
service and repair.
Links
This documents includes links that can be applied
when viewed electronically. Links are identified by a
dark grey line under the linked text.
L496 G
The warnings and cautions should be read carefully
to help prevent personal injury and to assure that
proper methods are used. Improper maintenance,
service or repair can cause damage to the vehicle and
other property, personal injury, an unsafe operating
condition or void the manufacturer’s warranty.
3
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Carefully read, understand and follow all safety related
information within this publication.
• While Hendrickson does not offer
asbestos brake linings, long term
affects of some non-asbestos
fibers have not been determined.
Current OSHA Regulations
cover exposure levels to some
components of non-asbestos
linings but not all. The following
precautions and considerations
must be applied when handling
these materials:
WARNING:DO NOT modify or rework parts.
Use ONLY Hendrickson authorized
replacement parts. Use of substitute,
modified or replacement parts not
authorized by Hendrickson may not
meet Hendrickson’s specifications. It
can also result in failure of the part,
loss of vehicle control and possible
personal injury or property damage.
Do not modify parts without written
authorization from Hendrickson.
• Compressed air or dry brushing
must never be used for cleaning
brake assemblies or work area.
warning: Always wear proper eye protection
and other required PPE (personal
protective equipment) when
performing vehicle maintenance,
repair or service.
• Hendrickson recommends that
workers doing brake work must
take steps to minimize exposure
to airborne brake lining particles.
Proper procedures to reduce
exposure include working in well
ventilated area, segregation of
areas where brake work is done,
use of local filtered ventilation
systems or use of enclosed cells
with filtered vacuums.
Warning: Solvent cleaners can be flammable,
poisonous and can cause burns. To
help avoid serious personal injury,
carefully follow the manufacturer’s
product instructions and guidelines
and the following procedures:
• Respirators approved by the Mine
Safety and Health Administration
(MSHA) or National Institute for
Occupational Safety and Health
(NIOSH) should be worn at all
times during brake servicing.
• 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.
• Workers must wash before eating,
drinking or smoking; shower after
working and should not wear work
clothes home. Work clothes should
be vacuumed and laundered
separately with out shaking.
• 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.
• OSHA Regulations regarding
testing, disposal of waste and
methods of reducing exposure for
asbestos are set forth in 29 Code
of Federal Regulations §1910.001.
These Regulations provide
valuable information which can
be utilized to reduce exposure to
airborne particles.
WARNING: Avoid creating dust. Dust from brake
pads and/or parts is a possible cancer
and lung disease hazard.
• Material Safety Data Sheets
(MSDS) on this product, as
required by OSHA, are available
from Hendrickson.
4
L496 G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
1
CAUTION: A mechanic 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 provided
instructions assume all risks of
consequential personal injury or
damage to equipment.
•
CAUTION: Brake lining contains non asbestos
fibers. Wear approved eye protection
and respirator when working on or
near the brakes to prevent a possible
health hazard.
•
•
•
•
Notice:When welding to or on the axle, take
every caution to prevent bearing
damage. When grounding welding
equipment to axle, prevent current
from passing through the wheel
bearings
Phone
Contact Hendrickson directly in United States
at 866‑RIDEAIR (743‑3247) or in Canada at
800‑668‑5360. From the menu, select:
• Technical Services/Warranty for technical
information.
• Other selections include:
–– Aftermarket Sales for replacement parts
information and ordering.
–– Original Equipment Sales for parts inquires and
ordering for trailer manufactures.
A connection that places a wheel
tearing between the ground cable
connection and the weld area can
damage the bearing by electric
arcing.
Contacting Hendrickson
Contact Hendrickson Trailer Technical Services for
technical assistance as needed. To do so, several
options are available.
Email
For Hendrickson Trailer Technical Services, use the
following e-mail address:
Prior to contacting Technical Services, it may be
best to have the following information about your
Hendrickson suspension available (all that apply):
• Suspension ID Tag information (Refer to
Hendrickson Lit. No. L977 ID Guide, page 2 for tag
location and details):
–– Suspension model number
–– Suspension serial number
–– Approximate number of suspension miles.
[email protected]
Relative Literature
If you suspect your version of this or any other
Hendrickson manual is not “Up-to-Date”, the most
current version is free online at:
www.hendrickson-intl.com/literature/
• Vehicle VIN number. Refer to trailer OEM manual for
VIN plate location.
–– Trailer Type (van, reefer, flat bed, etc...)
–– Manufacturer
–– VIN (vehicle identification number)
L496 G
–– In-service date If applicable, description of the system problem,
part number and/or part description of the reported
non-functioning part.
–– Date of failure
–– Where applicable: location of problem on
suspension / trailer; e.g., road side, front axle,
rear axle, curb side rear, etc
–– Symptoms»» Systems, components or function effected by
failure.
»» When does failure occur?
»» How often do they occur?
»» Etc...
What troubleshooting and/or measurements have
been performed?
What service data literature do you have or need?
Digital photos of suspension and damaged areas.
Special application approval documentation
(if applicable).
Available Hendrickson documentation can be viewed
or downloaded from this site.
1 If the in-service date is unknown or not available, the vehicle date of
manufacture can be substituted.
5
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Preparing Trailer for Service
All Hendrickson online documentation are PDF files
that require Adobe Acrobat Reader to open. This is a
free application downloadable from Adobe’s home
page (http://get.adobe.com/reader/).
NOTE:DO NOT service a suspension or any
component that is under warranty without
first Contacting Hendrickson Technical
Services.
Other relative literature may include:
Lit No.
Description
L583
Comprehensive Warranty Statement
L776
HUS® Wheel-end Maintenance Procedures
L974
Drum Brake Maintenance Procedures, section
“RETRACTING THE BRAKE SHOES OR SLACK
ADJUSTER CONTROL ARM(S)”
T71004
ADB Torque Plate Mounting Specifications
T71005
PRECISION320™ Nut Installation poster
T72002
HXL7® Wheel-end Maintenance Procedures
T72004
HLS® Wheel-end Maintenance Procedures
T72005
HVS® Wheel-end Maintenance Procedures
T72006
HXL3™ Wheel-end Maintenance Procedures
T72007
HXL5™ Wheel-end Maintenance Procedures
T77001
PRECISION320™ Nut Compatibility
T77002
PRECISION240™ Nut Compatibility
ConMet
PreSet™
Refer to Vendor Links on the Hendrickson Literature
web page.
warning: To prevent serious eye injury, always
wear safety glasses when performing
trailer maintenance and service.
Table 1: Relative wheel-end literature
TMC RP
Figure 1: Trailer preparation
Description
RP 211
Rim and Wheel Selection and Maintenance
RP 217
Attaching Hardware for Disc Wheels
RP 219
Radial Tire Wear Conditions and Causes
Before beginning any work on a trailer suspension
system, the following steps help to ensure conditions
are safe. Refer to General Service Notes on
page 3.
RP 222
User’s Guide to Wheels and Rims
1. Park the trailer on a level, debris-free surface.
RP 238
Troubleshooting Disc Wheel Looseness
RP 609
Manual and Automatic Slack Adjuster Removal,
Installation and Maintenance
RP 622
Wheel Seal and Bearing Removal, Installation, and
Maintenance
RP 624
Lubricant Fundamentals.
4. Exhaust the air from the trailer suspension.
RP 631
Recommendations for Wheel End Lubrication
RP 644
Wheel End Conditions Analysis Guide
5. Release the trailer parking brakes.
RP 656
Hub and Spoke Wheel Fastener Maintenance
2. Set the trailer parking brakes.
3. To prevent the trailer from moving, chock the
wheels of an axle not being raised.
6. Using a jack, raise trailer until wheels clear the
work surface.
Table 2: TMC Recommended Practice (RP) for wheel ends
7. Support the raised trailer with safety stands.
warning: Do not work under a trailer supported
only by jacks. Jacks can slip or fall
over, resulting in serious personal
injury.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Hendrickson Wheel-end Types
Hendrickson Long-Life System™ (HLS®) and
Hendrickson Value System™ (HVS®)
The differences are warranty period and types
of lubricant. With a five-year limited warranty,
HLS systems feature synthetic semi-fluid grease
(Chevron Delo® Synthetic Grease SF), while HVS
comes with oil bath lubrication (75W-90 synthetic
gear lube or SAE 80W / 90W gear oil) and a threeyear limited warranty. Spindle types include HN
(tapered) or HP (parallel). All components are field
serviceable however, no service of any kind should be
attempted without first Contacting Hendrickson.
Several types of hub/wheel-end assemblies can be
found on Hendrickson suspensions. These fall into
one of two categories: Hendrickson Standard
Service or Hendrickson Extended Service™
(HXS®). (refer to Table 1 on page 6 for a list of
documentation on the various wheel-end types):
Hendrickson Standard Service
The Standard Service wheel end is a conventional
wheel end (with hub, seal, lubricant and bearings)
that is factory installed by Hendrickson. Spindle
types include HN (tapered) or HP (parallel). Refer to
Introduction on page 8.
Hendrickson Extended-Life 3-year System™
(HXL3™)
HXL3 comes with oil bath lubrication (75W-90
synthetic gear lube or SAE 80W / 90W gear oil) and a
three-year limited warranty. Spindle types include HN
(tapered) or HP (parallel). All components are field
serviceable, however, no service of any kind should be
attempted without first Contacting Hendrickson.
Hendrickson Extended Service™
(HXS®)
Hendrickson Extended Service Wheel Ends offer
premium performance and are factory pre-assembled,
adjusted, sealed and lubricated on a Hendrickson
dressed axle. Hendrickson selects the components
and controls the seal installation, internal cleanliness,
environment, bearing adjustment and assembly
for an extended-service warranty beyond that of a
Standard Service Wheel End. All components are field
serviceable however, no service of any kind should be
attempted without first Contacting Hendrickson.
Hendrickson Extended-Life 5-year System™
(HXL5™)
HXL5 systems feature synthetic semi-fluid grease
(Chevron Delo® Synthetic Grease SF). Spindle types
include HN (tapered) or HP (parallel). All components
are field serviceable, however, no service of any
kind should be attempted without first Contacting
Hendrickson.
ConMet PreSet™
The hub, seal, spacer and bearings are factory
assembled and installed as a complete subassembly,
eliminating the need for individual seal and bearing
installation and adjustment. All components are field
serviceable. Spindle types include HN (tapered) or HP
(parallel). Refer to vendor literature for information and
maintenance procedures.
Hendrickson Extended-Life 7-year System™
(HXL7®)
HXL7 systems features ductile iron, ADI or
aluminum hub and synthetic semi-fluid grease
(Chevron Delo® Synthetic Grease SF). Spindle type
includes HP (parallel) only. All components are field
serviceable, however, no service of any kind should be
attempted without first Contacting Hendrickson.
Hendrickson Unitized System™ (HUS®)
A unitized hub system that is fully integrated, preadjusted and permanently sealed and lubricated.
It also is installed as a complete subassembly,
eliminating the need for individual seal and bearing
installation and adjustment. Except for the shoulder
seal, hubcap, hubcap O-ring, wheel studs and lug
nuts, no components are field serviceable. Should it
become necessary, the entire hub must be replaced as
an assembly.
Notice:Accessory-type hubcaps, such as
the chrome “top hat” style hubcap,
increase wheel-end temperatures
during operation and are not
recommended for use on Hendrickson
HLS®, HVS®, HUS®, HXL3™, HXL5™ or
HXL7® extended-service wheel ends.
Note:Hendrickson recommends HP spindle type
for super single tire applications. Refer to
L846 Wide Base Tire Configurations for more
details.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
3-piece nut detail view
Installed set screw
HP spindle
Cast / Spoke hub
Hub seal
Inner Bearing
HN spindle
Stemco® PRO-TORQ®
one-piece spindle nut
Standard Service (conventional) hub:
Aluminum, Ductile iron or
ADI (Austempered ductile iron)
Castle nut washer
Castle nut
Cotter key
Outer bearing
Rotor
Air disc brake (ADB)
hub and rotor assembly
Hub fill plug
and port
3-piece nut system
•Inner adjusting nut
•Lock washer / set screw
•Outer jam nut
Hubcap gasket
Hubcap
Hubcap
oil fill port
Figure 2: Hendrickson’s Standard Service wheel-end parts identification
Introduction
considered conventional hubs that are maintained and
assembled similarly.
Hendrickson’s Standard Service Hub Assembly is
a basic hub that applies conventional assembly
processes
defined in this document and the
2
TMC (Table 2 on page 6). For this process,
components (hub, seal, inner and outer bearings) are
specified and individually assembled, one at a time,
onto the spindle (or into hub bore). The Standard
Service wheel end includes components available
from Hendrickson, but specified by the customer.
Whereas Hendrickson’s Extended Service wheel
ends are Hendrickson specified by RTR model and
factory installed at Hendrickson. Each are delivered
as complete subassemblies on a dressed axle (see
Table 1 on page 6).
ADB Hub/Rotor
For air disc brake (ADB) systems, the caliper must
be removed before removing the hub and rotor
assembly. ADB rotor and caliper mounting is defined
in T71004 ADB Torque Plate Mounting Specifications.
Original mounting hardware must be discarded, once
removed, and replaced with new hardware installed as
instructed in T71004.
For information on ADB component replacement or
repair, refer to the respective ADB caliper supplier
documentation. Links to Bendix and Haldex ADB
literature is provided on Hendrickson Trailer’s literature
web site.
The Standard Service hub may be constructed of
aluminum, austempered ductile iron (ADI) or ductile
iron and vendors include by ConMet®, Walther EMC,
Meritor™ or Webb. Spindle types include HN (tapered)
or HP (parallel). In these procedures, all hubs are
2 In some cases, Hendrickson’s recommended procedures may differ
from that of the TMC, in which case, Hendrickson’s procedure must
take precedence.
8
L496 G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Inspection
Tools Required
The following tools may be required during the
performance of some maintenance procedures:
Tool 1
End-play measurement. Refer to
Figure 5 on page 11.
Hub-mounted seal
driver (Figure 12)
Available from seal manufacturer
Spindle-mounted seal
driver (Figure 11)
Available from seal manufacturer
Torque Wrench
(10 - 400 ft-lb or
13 - 542 N•m)
To be used with sockets for torqued
bolts and nuts listed in this table.
/2 inch socket
Hubcap fasteners
/4 or /16 inch hex key
Lube fill port plug
1
5
HN spindle
33/4 inch socket
Note: Suggested inspection intervals are based on
an average trailer usage of 100,000 miles
(160,000 km) per year. Higher usage would
require more frequent inspections. Conversely,
lower usage would require less inspection.
Refer to T12001 Inspection and Lubrication
for more details.
Inspections should be performed:
• Daily pre-operation check. This would include a
general walk around to check for signs of obvious
damage, wear or other abnormalities.
• Every month, visually inspect back of hub and
hubcap gasket for leakage. Refer to the section
titled Checking for Seal Leaks for complete
inspection details.
• Every three to four months:
–– Perform monthly inspection.
–– Check for smooth rotation.
»» Refer to the section titled Checking for
Smooth Rotation for details.
»» If hub feels rough, sounds noisy or does not
rotate freely; Checking End Play and/or
make necessary repairs.
• During brake service and relining when the wheel
end will be dismantled enough to easily make
these inspections. In addition to the inspection
at brake service, always maintain current shop
preventive maintenance and pre-trip inspection
practices.
Stemco® Pro-Torq® nut
For three-piece nut system
3 /8 inch socket
Inner Adjusting nut
31/4 inch socket
Outer jam nut
7
/64 inch hex key
5
Set screw
4 /4 inch socket
Stemco Pro-Torq nut
4 /4 inch socket
Castle nut
3
3
HP spindle
warning: Prior to performing inspection
procedures, help ensure conditions
are safe by following steps in section
Preparing Trailer for Service.
Where Used
Dial Indicator, with
mounting stand
(resolution to 0.001",
0.0254 mm)
1
As a general practice, the hub assembly should be
checked for seal leaks and smooth rotation.
For three-piece nut system
47/8 inch socket
Inner Adjusting nut
4 /8 inch socket
Outer jam nut
3
/64 inch hex key
5
Set screw
Table 3: List of required tools
Important: Torque cannot be properly applied
with an ordinary wrench. A calibrated
torque wrench must be used to
tighten fasteners to specified values
with even distribution of applied forces.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Checking for Seal Leaks
Checking for Smooth Rotation
The hub assembly is filled with grease or oil at the
factory during the assembly process. On the inboard
side, lubricant is contained in the hub by the hub seal
where leakage can occur (Figure 2 on page 8).
Many factors can effect smoothness of rotation.
Primary causes include:
• Bearing wear
• Damaged hub seal
• Moisture
• Unwanted debris
NOTE:A reasonable assessment can be performed
without removing tires and rims. However, this
procedure is best performed with hub only as
shown in Figure 6.
1. Ensure trailer is secure per Preparing Trailer
for Service on page 6.
Figure 3: Check back side of hub for grease seal leak
2. Disengage brakes and, if brake shoes, remove
brake drum (recommended).
To check for leaks, look at the inboard side of the hub,
(Figure 3). A small amount of lubricant may be visible
at the hub seal. This is a normal occurrence and
does not necessarily indicate a seal leak.
Some grease
may appear in
this area
3. While maintaining physical contact, slowly rotate
hub in both directions at least five revolutions.
4. During rotation, ensure smooth and quiet
rotation. Bearings should move smoothly. Feel
for any resistance in movement. Any debris in
bearings should be felt as it moves over rollers in
bearings.
Hubcap
gasket
Outboard
side
Inboard
side
Important: Any mechanical system with moving
parts is going to experience some
wear between its parts. If rotation feels
rough, sounds noisy, or does not rotate
freely. Take corrective action. DO NOT
place the suspension back into service.
Spindle bearing
shoulder
A. If rotation feels normal, return to previous
procedure or reassemble and restore trailer to
normal operation.
Figure 4: Spindle bearing shoulder
A small amount of lubricant may also appear at the
spindle bearing shoulder to hub joint (Figure 4) This
is also normal and does not necessarily indicate a
seal leak. It should be wiped clean to minimize any
accumulation of dirt.
B. If rotation sounds noisy, check end play.
C. If rotation feels rough or does not rotate freely,
refer to Contacting Hendrickson on
page 5.
NOTICE:Pressure or steam washing should be
avoided in this area as water could
be forced past the seal and degrade
lubricant performance and corrode
bearings.
If the hub seal is leaking, a large quantity of lubricant
will be present. Oil will be spattered on rim and tires.
If this is the case, the seal and other components may
need to be replaced. Take corrective action as needed.
10
L496 G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Checking End Play
This procedure should be performed when:
• Issues are identified during Checking for
Smooth Rotation.
• After installing hub and when instructed by spindle
nut installation procedure.
Rotate and
push hub
1. If not already done so:
A. Perform Preparing Trailer for Service
on page 6.
B. Remove wheel (tires and rims).
C. Remove hubcap and discard gasket.
D. Disengage brakes and, if brake shoes,
remove brake drum (recommended).
Figure 6: Checking inward end-play
Important: End play can be checked with brake
drum installed or removed (preferred).
If installed, make sure all brake
drum wheel fasteners are installed
and tightened to manufacturers
specifications before checking end
play.
7. Grasp hub as shown in Figure 6, and rotate the
hub in both directions while pushing the hub
inward until the dial indicator reading remains
constant. Record reading.
Rotate and
pull hub
2. Ensure hub hubcap mounting surface and end of
spindle are clean and totally free of any burrs or
debris.
Figure 7: Checking outward end-play
8. While still grasping hub (Figure 7), pull hub
outward until the dial indicator reading remains
constant. DO NOT rotate while pulling. Record
reading.
Figure 5: Checking end play
3. Rotate hub at least 5 revolutions to ensure
bearings are fully seated.
9. Calculate difference between recorded values of
Step 7 and Step 8 to determine end play, record
value.
4. Attach dial indicator (Table 3) with magnetic
base to flat surface at end of spindle (Figure 5).
Important: End play should be between 0.001"
(0.0254 mm) and 0.005" (0.127
mm).
5. Adjust dial indicator so its pointer line of action is
parallel to spindle axis and touches hub.
A. If end play is within specification, no bearing
adjustment is necessary. Continue to final
Step 10.
6. Zero indicator.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Removing and Installing Hub
B. If checking after Install Spindle nut on
page 17 and end play is less than 0.001"
(0.0254 mm); Loosen spindle nut and adjust
to next closest position of lock washer.
warning: Prior to performing maintenance
procedures, ensure conditions are
safe. Refer to Preparing Trailer
for Service on page 6.
Note:If using a three-piece spindle nut system and
a smaller loosening increment is desired”:
i. Remove lock washer from spindle, flip
it over, reinstall it on spindle and loosen
inner adjusting nut so its dowel aligns
with the previous alignment hole in lock
washer.
ii. Slide lock washer up against inner
adjusting nut and install outer jam nut.
Tighten nut according to Table 4 on
page 18.
iii. Return to step 3 on page 11 and
repeat end play procedure.
Note:In order to maintain warranty status,
Contacting Hendrickson is recommended
before removing the hubcap and disturbing
the spindle nut.
Removal of hubcap fasteners and/or hubcap
(old gasket must be discarded and replaced
with new, torque fasteners to 5±3 ft. lbs.,
20±2 N•m) is allowed when:
• Attaching hubometer bracket.
• Performing a TIREMAAX installation.
C. If end play is greater than 0.005" (0.0254
mm), tighten spindle nut (Install Spindle
nut on page 17) or refer to Contacting
Hendrickson Technical Services.
Hub Removal
Use the following procedure to remove hub assembly:
1. Remove tire / wheel assembly.
Important:Do not place suspension back into
service without correcting the problem.
2. Disengage brakes and
If brake shoes, remove brake drum.
10.If:
If ADB, remove caliper according to
manufacturer’s procedures. Refer to T71004 ADB
Torque Plate Mounting Specifications, page 2. New
caliper mounting hardware must be used.
A. Performing end play check only, ensure
spindle nut system is securely in place, go to
Install Hubcap on page 20.
B. Checking as part of spindle nut installation,
return to Install Spindle nut on page 17
to complete spindle nut assembly:
Spindle Nut System
step 10 on page 18
Stemco PRO-TORQ
Install Hubcap on page 20
Castle spindle nut
Install Hubcap on page 20
®
Remove Spindle Nut
One of three spindle nut systems (Figure 8 through
Figure 10) is used to secure a standard service hub to
the spindle/axle:
• Standard three-piece spindle nutst
• Stemco® PRO-TORQ® one-piece spindle nut
• Castle spindle nut (HP spindles only)
Return to
Standard three-piece
®
3. Remove hubcap bolts (Table 3) and hubcap,
discard gasket.
Each of these spindle nut systems has a different
locking mechanism which must be disengaged before
spindle nut(s) can be removed (Step 1).
1. Disengage spindle nut locking mechanism as
follows:
12
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
A. Standard three-piece nut (Figure 8)-
ii. Slide keeper off spindle keyway.
C. Castle spindle nut system, HP spindle only
(Figure 10) - Remove and discard cotter pin.
Inner adjusting
nut
Lock washer
Cotter pin
Spindle
Outer jam
nut
Set
screw
Figure 8: Three-piece nut system components
i. Using a 5/64 inch hex key, remove set
screw from interlock washer.
ii. Remove spindle nuts and lock washer.
Figure 10: Castle spindle nut system (HP spindles only)
2. Remove spindle nut(s) and washer or lock
washer (if equipped).
B. Stemco PRO-TORQ one-piece nut (Figure 9) -
Remove Hub
After the spindle nut is removed, the hub is free to
be gently removed from the spindle while avoiding
damage to spindle and spindle threads.
Spindle
Caution: For safety reasons and to prevent
damage to hub and spindle, lifting
equipment may be required to lift
and support the hub as it is being
removed from the spindle.
Keeper
NOTICE:Any damage to spindle or hub
machined surfaces can affect wheel
end performance.
Pry here with
screwdriver
1. Carefully pull hub assembly slightly toward
spindle end. A short quick motion should allow
outer bearing to exit the hub. Be prepared to catch
outer bearing if it slides off the end of the spindle.
Otherwise, simply remove it.
Undercut groove
Figure 9: Stemco® PRO-TORQ® one-piece spindle nut system
(HN & HP spindles only)
2. Remove hub from spindle. The inner bearing is
held in hub by the hub seal and should come off
with hub.
i. Using a flat-blade screwdriver, remove
orange keeper from nut. Carefully pry both
keeper arms from undercut groove in the
nut until keeper releases.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Assemble Hub
3. Remove and discard hub seal:
Now that the spindle and hub are cleaned and
lubricated, hub assembly can begin. Hub assembly
includes:
• Hub Seal and inner bearing
–– Spindle-mounted seal
–– Hub-mounted seal
• Hub and Outer Bearing (Oil Lube only) on
page 15
• Hub and Outer Bearing (SF Grease Only) on
page 16
• Hub and Bearings (NLGI #2 Grease) on
page 16
A. If the seal is in the hub - a pry bar can be
used to carefully remove seal from hub bore.
Damage to hub and hub surfaces must be
avoided.
B. If the seal is on the spindle - Using a brass,
leather or other soft-faced mallet, drive seal off
spindle by carefully striking seal from the back
side.
Spindle Preparation
Before installing hub, follow this procedure to ensure
spindle machined surfaces are clean and undamaged.
1. Remove old lubricant and thoroughly clean
spindle.
Notice:The HUB SEAL CAN BE DAMAGED or
prematurely fail if:
2. Inspect machined spindle seal surface for nicks,
scratches, burrs or marks. If needed, use crocus
cloth or emery cloth to repair any damaged areas.
• Hub seal is improperly installed.
• Hub seal is rammed into the
spindle bearing shoulder.
3. Clean spindle threads and keyway thoroughly
with a wire brush to avoid false bearing
adjustments and to avoid introduction of
contaminants into the lubricant cavity.
• Hub is not kept supported and
aligned with spindle until the
outer bearing and axle nut are
installed.
4. Thoroughly clean spindle machined surfaces of
rust, dirt, grease or any contaminants that could
damage the hub seal and cause it to leak.
• Do not mix lube types during hub
assembly.
Caution: For safety reasons and to prevent
damage to hub and spindle, lifting
equipment may be required to lift
and support the hub as it is being
installed on the spindle.
5. Lubricate spindle with same lube used to fill hub.
Prepare Hub for Install
The hub and bearings should be cleaned and
inspected prior to installation.
1. Thoroughly clean the hub bore of any dirt, grease,
rust or any other substance that may be present.
Spindle-mounted seal
This type of seal is mounted on the spindle before
installing the hub. The replacement seal should be
same brand and type as originally installed by the OE.
A recommended installation tool, with instructions, is
available from the seal manufacturer.
2. Inspect hub seal bore for roughness. If needed,
use emery cloth to remove any burrs or old bore
sealant, and wipe hub clean.
3. Remove all sharp edges, nicks and burrs from
seal bore, hubcap bore and hubcap mounting
surface of the hub.
4. Ensure hubcap mounting surface is smooth and
free of debris.
5. Lubricate hub bearing surfaces with same lube
used to fill hub.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Seal
Drive tool
Drive tool
Seal
Figure 11: Spindle-mounted seal installation
1. Lubricate seal according to seal manufacturer’s
recommendations, then place it on the spindle
(Figure 11).
Figure 12: Hub-mounted seal installation
1. Lubricate hub. Refer to TMC RP 631 (Table 2 on
page 6) for complete lubrication details.
2. Place installation tool over the spindle and drive
seal until it is flush with the bearing shoulder.
2. Apply lubricant to spindle, bearing journal ,
hub cavity (between bearing cups), bearings
cups within hub, bearing and cones. If NLGI #2
grease is used, pack bearing with grease before
installing.
3. Rotate installation tool and apply several light
blows to ensure seal is properly seated against
bearing shoulder.
4. Lubricate inner bearing journal and cone. If NLGI
#2 grease is used, pack bearing with grease
before installing.
Notice:To inhibit fretting, use same lube
used to fill hub.
5. Install inner bearing onto spindle. If it becomes
misaligned, using a small hammer, tap lightly
on the unmachined part of the axle tube. This will
create vibration and help realign the bearing on
the spindle and ease installation.
3. Install inner bearing into hub against inner
bearing cup properly.
4. Lubricate seal according to the seal
manufacturer’s recommendations, then place it on
an installation tool (Figure 12).
Hub-mounted seal
This type of seal is mounted directly to the hub inner
bore before installing hub. The replacement seal
should be same brand and type as originally installed
by the OE. A hub-mount seal installation tool, with
instructions, is available from seal manufacturer.
A. Align tool with hub seal bore.
B. Drive seal until it bottoms out in the hub seal
bore.
C. Rotate installation tool and apply several light
blows to ensure seal is properly seated.
D. Check inner bearing to make sure it rotates
freely.
Hub and Outer Bearing (Oil Lube only)
With seals in place, the hub and outer bearing can
now be installed onto spindle.
1. Gently slide hub onto spindle, taking care not to
damage seal.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
2. Lubricate outer bearing and install into hub.
Notice:When complete, the hub should be
filled to 50% of hub cavity (to 3 & 9
O’clock position when viewing from
end of spindle) as defined in RP 631.
Any air bubbles or aeration of grease
may result in insufficient grease
quantity, bearing spalling and wheelend damage.
Note:While sliding hub onto spindle, oil is collected
at the spindle bearing shoulder inboard of the
hub (Figure 4 on page 10).
3. Clean spindle and hub area as needed.
4. Refer to TMC RP 631 for more details and tips for
lubricating hub bearings.
3. Pre-lube outer bearing.
5. Continue with Install Spindle nut on
page 17.
4. Place grease coated outer bearing over spindle
and against the Hub SF Grease Dam.
Hub and Outer Bearing (SF Grease Only)
5. Slide dam out as the bearing is inserted into the
hub bearing race.
Important: This procedure only applies to the
use of semi-fluid (SF) grease and the
use of the Hub SF Grease Dam on
page 21.
6. While sliding hub onto spindle, grease is collected
at spindle bearing shoulder inboard of hub. Clean
as needed.
7. Refer to TMC RP 631 for more details and tips for
lubricating hub bearings.
With seals in place, the hub, grease and outer bearing
can now be installed, in that order.
8. Continue with Install Spindle nut on
page 17.
Note:This procedure assumes equipment required
to dispense grease through the hub fill port
(Figure 2 on page 8) is not available
and the use of a Hub SF Grease Dam on
page 21, must be applied.
Hub and Bearings (NLGI #2 Grease)
With seals in place, the hub, grease and outer bearing
can now be assembled onto the spindle, in that order.
1. Gently slide hub onto spindle, taking care not to
damage seal.
1. Pack hub cavity with grease. Be sure to fill
cavity, all around, to the level of the bearing races
according to TMC RP 631.
Notice:The HUB SEAL CAN BE DAMAGED if:
Notice:The inner bearing should also have
been previously packed with NLGI #2
grease before installation.
• Hub seal is improperly installed.
• Hub seal is rammed into the
spindle bearing shoulder.
2. Gently slide hub onto spindle, taking care not to
damage seal.
• H
ub is not kept supported and
aligned with spindle until the
outer bearing and axle nut are
installed.
3. Lubricate outer bearing and install into hub.
Note:While sliding hub onto spindle, grease is
collected at the spindle bearing shoulder
inboard of the hub (Figure 4 on page 10).
2. Fill hub cavity to 50% capacity with grease
according to TMC RP 631. Table 6 includes
estimated quantities for various hubs.
4. Clean spindle and hub area as needed.
Note:The use of a Hub SF Grease Dam on
page 21 is recommended as defined in RP
631. Refer to Making a Hub SF Grease Dam
on page 21 for instructions on making the
dam and its application.
5. Pack outer bearing with grease, then install onto
spindle and into hub.
6. Refer to TMC RP 631 for more details and tips for
lubricating hub bearings.
7. Continue with Install Spindle nut.
16
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Install Spindle nut
Spindle
keyway
slot
Three types of spindle nut systems may be used to
secure a conventional hub to the spindle/axle:
• Standard three-piece spindle nut
• Stemco® PRO-TORQ® spindle nut on
page 18
• Castle spindle nut (HP spindles only)
on page 19
Dowel
Lock washer
Each nut system is assembled and torqued differently.
Figure 14: Adjusting nut and lock washer installation
WARNING: FAILURE TO FOLLOW THESE
INSTRUCTIONS COULD CAUSE WHEEL
TO COME OFF AND CAUSE BODILY
INJURY.
1. Install inner adjusting nut (Figure 14) on spindle,
dowel side out, and tighten to 200 ft. lbs. (271
N•m) of torque while rotating wheel.
2. Back off inner adjusting nut one full turn.
OVER-TIGHTENING NUT COULD
CAUSE BEARINGS TO RUN HOT AND
BE DAMAGED.
3. Rotate wheel at least 5 revolutions to seat
bearings.
Standard three-piece spindle nut
The three-piece spindle nut system (Figure 13 on
page 17) includes an inner adjusting nut, lock
washer and inner jam nut.
Inner adjusting
nut
Lock washer
Tang
Inner adjusting nut
4. Tighten inner adjusting nut to 50 ft. lbs. (68
N•m) of torque while rotating wheel.
5. Back off the inner adjusting nut ¼ turn.
Spindle
Dowel and hole aligned
Outer jam
nut
Set
screw
If dowel and hole do not
align, flip lock washer over
Figure 15: Align adjusting nut dowel with hole in lock washer
6. Install lock washer (Figure 14). Make sure lock
washer tang fits in the spindle keyway slot and
inner adjusting nut dowel fits in one of the holes
in the lock washer. If this alignment cannot be
achieved, remove the lock washer, flip it over and
reinstall it on spindle (Figure 15).
Notice:DO NOT tighten inner adjusting
nut for dowel pin alignment. This
can excessively pre-load bearings,
resulting in premature failure.
Figure 13: three-piece nut system components
If the dowel and hole still don’t line up, loosen the
inner adjusting nut slightly until alignment occurs.
7. Install outer jam nut (Figure 2 on page 8).
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
8. Tighten outer jam nut to:
Spindle
Torque
HN
315 ft. lbs. (427 N•m)
HP
385 ft. lbs. (522 N•m)
Stemco® PRO-TORQ® spindle nut
Follow this procedure to install Stemco Pro-torq nut on
Hendrickson wheel ends.
Tab
Table 4: Outer jam nut torque values.
9. Perform Checking End Play on page 11.
Return to next step when procedure is complete.
Keyway tang
10.Install set screw (Figure 2 on page 8) into
an accessible threaded hole in lock washer
(Figure 13). Set screw must contact inner
adjusting nut. Tighten to 16-20 in. lbs. (1.8-2.2
N•m) of torque.
These tabs, (and the tab
at top) fit into undercut
groove in PRO-TORQ®
spindle nut.
Spindle
keyway
Inspecting Installation
To ensure correct installation, follow these procedures:
Keeper
1. Make sure lock washer is properly positioned
and flush with inner adjusting nut at dowel pin
(Figure 13 and Figure 15).
2. Ensure set screw contacts nut face. When properly
installed, the set screw will be approximately half
the height of the outer jam nut.
3. Test for free hub rotation, perform Checking for
Smooth Rotation on page 10.
Figure 16: Stemco® PRO-TORQ® spindle nut and keeper
Install and Adjust Nut
1. If necessary, remove keeper from PRO-TORQ nut
(Figure 9 on page 13). Using a screwdriver,
carefully pry the keeper arm from the undercut
groove on each side until the keeper releases.
2. Install PRO-TORQ nut onto spindle and hand
tighten.
3. Using a torque wrench, tighten nut to 200 ft. lbs.
(271 N•m) of torque. This ensures bearing cups
are properly seated in the hub.
4. Rotate hub at least one full revolution.
5. Repeat Step 3 and Step 4 two more times, but do
not rotate after final torque.
6. Back off nut until it is loose.
7. Using a torque wrench, tighten nut to 100 ft. lbs.
(135 N•m) of torque.
8. Rotate hub at least one full revolution.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
9. Repeat Step 7 and Step 8 two more times, but do
not rotate after final torque.
Castle spindle nut (HP spindles only)
Refer to Figure 10 on page 13 for illustration.
10.Back off nut:
1. Install castle nut washer and castle nut onto
spindle.
A. For HN spindle, 1/4 turn.
2. Tighten to 200 ft. lbs. (271 N•m) of torque while
rotating hub at least one full rotation.
B. For HP spindle, 1/8 turn.
Install Keeper
Keeper was removed in Step 1 of previous procedure.
3. Back off castle nut until it begins to feel loose. Do
not exceed ½ turn.
1. With bent legs and orange side facing out
(Figure 16 on page 18), Insert tab into
undercut groove in nut and engage keeper keyway
tang in spindle keyway.
4. Tighten castle nut to 50 ft. lbs. (68 N•m) of
torque while rotating hub at least one full rotation.
2. Engage mating teeth (Figure 9 on page 13).
With teeth engaged, if keeper tang does not align
with axle keyway, loosen nut slightly until it does.
DO NOT loosen nut more than one tooth (six
degrees).
6. Insert cotter pin through a groove in castle nut
and into a hole in spindle. Bend the long leg of
cotter pin to minimize castle nut movement.
5. Back off nut 1/8 turn.
Note:The cotter pin should extend into center of the
spindle (Figure 17). If a hole in the spindle
does not align with castle nut, loosen nut
slightly until closest spindle hole aligns with a
groove in castle nut.
3. Using a screwdriver, compress and insert keeper
arms, one at a time, into undercut groove in the
nut.
WARNING: DO NOT BEND OR MANIPULATE
KEYWAY TANG IN ANY WAY. DOING
SO MAY CAUSE TANG TO BREAK,
ALLOWING WHEEL TO COME OFF AND
CAUSE BODILY INJURY.
1.0"
4. Inspect installation. Make sure:
A. Keeper tab and keeper arms are fully seated in
the undercut groove.
B. Keyway tang does not contact the bottom
of the keyway. If contact exists, immediately
notify your PRO-TORQ representative.
5. Perform Checking for Smooth Rotation on
page 10.
Figure 17: Cotter pin/TIREMAAX potential interference
7. If the wheel end includes TIREMAAX®, it is likely
necessary to trim cotter key (Figure 17) to avoid
interference. Refer to T57001 TIREMAAX CP
& PRO Wheel-end considerations for details.
for more information on TIREMAAX, refer to the
literature website.
8. Perform Checking for Smooth Rotation on
page 10.
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Install Hubcap
Hub Lubrication
After hub installation and inspection is complete, the
hubcap can be installed.
For complete lubrication details, refer to:
• TMC RP 631 Recommendations for Wheel End
Lubrication.
• Seal and bearing manufacturer’s recommendations
for compatibility.
• Hub manufacturer for volumes.
• OEM or fleet recommendations.
Important: Always install a new gasket when
reinstalling hubcap.
Notice:Interference between nut system
and hubcap could occur if improper
components are used. Use only
genuine Hendrickson or Hendrickson
approved replacement components.
Refer to Relative Literature
on page 5 or Contacting
Hendrickson on page 5 as
needed.
For adding lubricant, most hubs have a fill port and
plug (Figure 2 on page 8), located on the side of
the hub approximately halfway between the bearings.
Hubs can be lubricated with either oil or semi-fluid
grease, as specified during original trailer build and/or
fleet requirements.
1. Visually inspect hubcap, hub mating surface, bolt
holes and new gasket for:
• Signs of damage
• Debris, such as silicon gasket sealer
• Burrs or sharp edges
• Cracks
Oil Lubricant
1. Remove fill port plug (Figure 2 on page 8) on
the side of the hub or at hubcap window plug (if
included).
2. Fill wheel end with oil. Refer to Table 5 on
page 21 for lube capacity at room temperature
(60° F, 16° C).
2. Clean, repair or exchange as needed. Protect
any exposed grease during the process. Replace
any quantity of grease lost during the process.
3. Check oil level at hubcap window.
Note:Allow sufficient time for oil to settle prior to
final oil level check (it may be necessary
to add oil more than once to adequately fill
wheel end)
3. Align hubcap and new gasket onto hub and
insert bolts.
4. Hand-tighten bolts.
5. Using a star pattern, torque hubcap bolts to 15±3
ft. lbs. (20±4 N•m) torque.
4. If oil was inserted through fill port in hub, Install
fill port plug and tighten to 22±2 ft. lbs. (30±3
N•m) torque.
Notice:Do not overtighten hubcap bolts.
Overtightening will distort metal
hubcap mounting flange, which will
prevent hubcap from achieving a
leak-free seal.
If oil was inserted through hubcap side fill port,
Install fill port plug and tighten to 7±2 ft. lbs.
(9±3 N•m) torque.
Otherwise, reinstall hubcap oil plug in window.
20
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Approximate Hub Lube Capacity
Semi-Fluid Grease Lubricant
Semi-fluid grease lubricant should only be used in
hubs with a fill port in the side of the hub.
Table 6 lists an approximate hub capacity for
semi‑fluid grease only. The values listed are intended
for reference only as hub manufacturers make design
changes which may effect the capacity. Less may be
required for NLGI #2 grease. Oil is filled to the “FULL”
level on the hubcap window and equates to less than
the SF grease capacity listed in the table.
Note:For more complete and alternative procedures,
refer to TMC RP 631 Recommendations for
Wheel End Lubrication.
1. Remove fill port plug (Figure 2 on page 8) on
the side of the hub.
Hub
Hub Type Capacity 1
Material
(Pints / Liters)
Material
HN
HP
Aluminum
1.18 / 0.56
2.60 / 1.23
Ductile iron
1.18 / 0.56
2.60 / 1.23
1.10 / 0.52
1.80 / 0.85
(Pints / Liters)
Drum
ConMet
Approximate Capacity 3
2
HN
HP
Aluminum
1.18 / 0.56
2.60 / 1.23
Ductile iron
1.18 / 0.56
2.60 / 1.23
Motor Wheel
Ductile iron
ConMet
Motor Wheel
Ductile iron
1.10 / 0.52
1.80 / 0.85
Walther EMC
Dura-Light (ADI) 2.00 / 0.95
2.70 / 1.28
Walther EMC
Dura-Light (ADI)
1.80 / 0.85
2.60 / 1.23
Webb
Ductile iron
1.20 / 0.57
2.00 / 0.95
Webb
Ductile iron
1.20 / 0.57
2.00 / 0.95
HN
HP
Aluminum
1.18 / 0.56
2.60 / 1.23
Ductile iron
N/A
3.40 / 1.60
1.10 / 0.52
1.90 / 0.90
Disc
ConMet
Gunite
1
2
3
4
Refer to TMC RP 631 general grease fill methods and procedures
that apply to all hub types.
Capacities stated are for the purposes of securing enough SF grease
to lubricate one hub to 50% full.
Austempered Ductile Iron (ADI)
Table 6: Approximate hub SF grease capacity
Capacity may very with hub design changes.
Hub SF Grease Dam
Refer to Hub and Outer Bearing (SF Grease Only)
on page 16 for instructions for grease lubricated
hub assembly.
Table 5: Lube (grease) capacity
2. Fill hub with grease. Refer to Table 5 for lube
capacity at room temperature (60° F, 16° C).
Making a Hub SF Grease Dam
To make a grease dam, follow the instructions on the
face of the template (Figure 18 on page 22). Use
cardboard, plastic or other flat stiff material.
3. Install fill port plug and tighten to 22±2 ft. lbs.
(30±3 N•m) torque.
Completing Installation
Applying the Hub Sf Grease Dam
Refer to Step 2 of Hub and Outer Bearing (SF
Grease Only) on page 16 for instructions on how
to use the Hub SF Grease Dam. Reference
TMC RP 631 for more application details, tips and
usage.
1. Spin hub more than three revolutions to distribute
lubricant equally in hub bore.
2. If brake shoes, Install brake drum and wheel (tire
and rim assembly) Refer to Brake Drum And
Wheel Assembly on page 26.
If ADB, install brake caliper according to
manufacturer’s procedures. Refer to T71004 ADB
Torque Plate Mounting Specifications, page 2. New
caliper mounting hardware must be used.
3. If service is complete, restore trailer to normal
operation.
L496 G
4
21
22
Hub SF Grease Dam
Cut out
and
discard
For assistance contact Hendrickson Technical Services
866-RIDEAIR (743-3247) or in Canada at 800-668-5360
1. Print one template for each spindle type (HN & HP).
2. Make a HN or HP grease dam from cardboard, plastic or other flat stiff material.
3. Use this grease dam when filling hub with semi-fluid grease to 50% full level.
4. Slide outer bearing over spindle and slide grease dam out while inseting bearing into hub.
For more details, refer to TMC RP 631.
HP Spindle
radius
HN Spindle
radius
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Figure 18: Hub SF Grease Dam template
L496 G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Torque Values
Table 7 lists torque values for wheel-end fasteners.
Fastener
Torque
ft. lbs.
N•m
Hubcap Screws
15±3
20±4
Hub fill port plug
22±2
30±3
475±25
644±25
Wheel Nuts 1, 2
Standard three-piece spindle nut on page 17
HN outer jam nut
HP outer jam nut
Set screw
315
427
385
522
18±2 in. lbs.
2.0±0.2
Stemco® PRO-TORQ® spindle nut on page 18
Adjust nut according to procedure listed.
Castle spindle nut (HP spindles only) on page 19
Adjust nut according to procedure listed.
1
2
These fasteners are incrementally tightened according to procedures
defined in this manual and superseded by OE documentation, where
applicable.
Re-torque all wheel nuts after 50 to 100 miles of service.
Table 7: Standard Service Wheel-end fastener torque values
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Wheel Stud Removal /
Installation Procedure
For a list of literature relative to hub and stud
maintenance, refer to Relative Literature on
page 5.
Stud Removal
1. Follow procedure Preparing Trailer for
Service on page 6 to secure trailer before
continuing to next step.
2. Raise axle so that wheel requiring stud removal /
replacement is off the ground.
3. Remove tire and wheel assembly.
Figure 21: Retracting brake shoes
Note:In some instances, it may be necessary to
slightly retract the brake shoes so the drum
can clear the brake shoe / lining assembly
(Figure 21).
For detailed slack adjuster instructions, see
to Table 1 on page 6 for “RETRACTING
BRAKE SHOES OR SLACK ADJUSTER
CONTROL ARM(S)” in L974 or Table 2 on
page 6 for TMC RP 609 instructions.
Figure 19: Identifying “old” studs
4. Using a paint stick or some other suitable marker,
mark studs to be replaced so they do not get
mixed up with new replacement studs (Figure 19).
Figure 22: Extracting studs
6. Use a stud remover (Figure 22) to extract stud(s).
Figure 20: Brake drum removed
Notice Do not use a hammer to remove
hub studs. Use of a hammer can
cause impact damage to the bearing
raceway, reducing bearing life.
5. If brake shoes, remove brake drum (Figure 20).
24
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Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
7. Discard all removed studs.
8. Record serial number of hub for future reference
and service records.
Stud Installation
This procedure is for installation of one stud. If more
stud is to be installed, repeat each step as needed.
1. Clean all related flat surfaces on hub with buffer
or crocus cloth.
Figure 24: Stud draw-in process
5. Complete stud draw-in process using a torque
wrench set to 300 ft. lbs. (407 N•m) (Figure 24).
With threads protected by a nut, a jack stand can
be used to prevent the hub from turning.
Figure 23: Installing new studs
2. Install new stud into hub (Figure 23). If possible,
line up knurls on the replacement stud with
impressions (grooves) in the hub stud hole.
3. Apply no more than two drops of oil to original
lug nut to ensure nut spins freely (Do not use
more than 2 drops of oil), and place nut on newly
installed stud.
Note:Some studs have threads that do not go the
full length of the stud. For these studs, the nut
will not contact with hub outer surface and
provide the clamp load necessary to pull-in
the stud. Either install stud with drum in place
or use hardened washers.
Figure 25: Checking stud installation
4. Use a ½ inch drive impact wrench to tighten nut
and draw replacement studs tight to hub inner
surface.
L496 G
6. Check stud installation with a 0.0015 inch feeler
gauge to make sure the bolt is seated (Figure 25).
7. Remove and discard nut when done. Do not
reuse this nut in new assembly.
25
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
Brake Drum And Wheel Assembly
With the stud pilot system (also known as the ball
seat, ball seat cap nut or double cap nut system;
Figure 27), the brake drum is centered on a pilot
boss just like the hub pilot system, but a spherical
radius contact area between the mounting nut and the
wheel centers the wheel on the hub. The entire wheel
assembly is fastened together by a single cap nut on
each wheel stud (for single wheel applications) or by
inner and outer cap nuts on each wheel stud (for dual
wheel applications).
Both hub pilot (Figure 26) and stud pilot (Figure 27)
wheel mounting systems are available on Hendrickson
suspensions.
With the hub pilot system (Figure 26), pilot bosses
(which are machined into the hub) center the brake
drum and tire/wheel assembly on the hub. The entire
wheel assembly is fastened together by a single flange
nut on each wheel stud for both single and dual wheel
applications.
Before reusing flange nuts that have already
been used in service, apply two drops of oil
at one point between the flange and the hex.
Flange
Hex
Brake Drum
Tire/wheel assembly
Flange Nut
Hub
Single
Dual
Figure 26: Hub pilot wheel mounting system
Tire/wheel assembly
Brake Drum
Spherical radius
contact area
Inner cap nut
Outer cap nut
Hub
Single
Dual
Figure 27: Stud pilot wheel mounting system
26
L496 G
Standard Service Wheel-end Maintenance Procedures Standard ServiceWheel-end Maintenance Procedures
The following information is intended to provide basic
brake drum and wheel installation instructions. Finer
details such as whether or not to use a corrosion
inhibitor, whether or not to lubricate the hub pilots,
use a wheel dolly or sling, etc., are left to the reader’s
discretion. Refer to hub and / or wheel manufacturer’s
installation instructions, TMC and your company’s
maintenance, service and installation practices for
complete installation details.
10
8
3
6
5
4
Assembly Procedures
7
1. Clean all mating surfaces on hub, drum, wheels
and nuts.
1
9
2
Figure 28: 10 stud tightening sequence
2. Rotate hub so a pilot boss is at the top (12
o’clock) position.
3. Mount brake drum on hub so it seats on drum
pilot and against hub face.
1
4. Mount wheel on hub. One or more wheel nuts can
be started in order to hold wheel and drum into
position.
5. Tighten top wheel nut first. Apply 50 ft. lbs. (68
N•m) of torque to draw wheel and brake drum up
fully against the hub.
6. Install remaining wheel nuts. Using sequence
shown in, tighten all wheel nuts to 50 ft. lbs. (68
N•m) of torque.
4
3
8
2
Figure 29: 8 stud tightening sequence
8. Check seating of wheel and brake drum at the
pilot bosses. Rotate wheel and check for any
rotational irregularity.
9. If so equipped, follow above steps for outer
wheel.
CAUTION: Re-torque all wheel nuts after 50 to
100 miles of service on the initial
“in-service” following any installation
of wheels to hub assembly.
L496 G
7
5
7. Repeating sequence shown in Figure 28 or
Figure 29, retighten all wheel nuts to 475±25 ft.
lbs. (644±34 N•m) of torque.
6
27
www.hendrickson-intl.com
Hendrickson Canada
250 Chrysler Drive, Unit #3
Brampton, ON Canada L6S 6B6
905.789.1030
Fax 905.789.1033
L496 Rev G 08-12 ECN 21353
Trailer Commercial Vehicle Systems
2070 Industrial Place SE
Canton, OH 44707-2641 USA
866.RIDEAIR (743.3247)
330.489.0045
Fax 800.696.4416
Hendrickson Mexicana
Circuito el Marqués Sur #29
Parque Industrial El Marqués
Pob. El Colorado, Municipio El Marqués,
Querétaro, México C.P. 76246
+52 (442) 296.3600
Fax: +52 (442) 296.3601
Information contained in this literature was accurate at the time of publication. Product changes may have been made after the copyright date that are not reflected.
© 2012 Hendrickson USA, L.L.C. (U.S. Rights) Hendrickson International Corporation (Rights Outside U.S.) All Rights Reserved
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