Technical
Procedure

Trailer Suspension Systems
Axle/Beam Weldment

SUBJECT: Replacement Procedures

LIT NO: L533 
DATE: December 2018
REVISION: A

TABLE OF CONTENTS
Important Safety Notices........................................................................................................................ 2
Related Literature......................................................................................................................................... 2
Introduction........................................................................................................................................... 2
Removing Existing Axle/Beam Weldment................................................................................................ 2
Install HALFTRAAX® ............................................................................................................................... 5

Axle/Beam Weldment Replacement Procedures 

IMPORTANT SAFETY NOTICES

INTRODUCTION

Hendrickson literature number T12007 Technical
Procedure General Safety Precautions and Information,
available at www.Hendrickson-intl.com/TrailerLit,
includes important preparation, precautionary and
safety information pertaining to the procedures
included in this document.

A HALFTRAAX™ or HTRAAX is an axle/beam weldment
configured as an aftermarket replacement for an
INTRAAX®, INTRAAX-SP, VANTRAAX® or ULTRAA-K® axle.
The replacement can be configured with or without
brakes or RTR® READY-TO-ROLL® wheel-end components
and TIREMAAX® tire pressure control system. It will not
include shocks, air springs or frame brackets.

To help prevent personal injury and equipment
damage; warnings, cautions and other related
statements included in T12007 must be read
carefully and applied during the performance of the
procedures included in this document.

Follow the procedures in this manual to replace an
existing axle/beam weldment with an aftermarket
HALFTRAAX.
NOTE: DO NOT service a suspension or any
components that are under warranty without
first contacting Hendrickson Trailer Technical
Services.

Improper maintenance, service or repair can cause
damage to the vehicle and other property, personal
injury, unsafe operating conditions and potentially void
the manufacturer’s warranty.

REMOVING EXISTING AXLE/BEAM
WELDMENT

RELATED LITERATURE

Ensure the trailer is secure as stated in T12007.

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:

1. Release parking brakes.
2. Using a jack capable of lifting the entire trailer,
raise the trailer until the wheels of the affected axle
assembly clear the surface.

www.Hendrickson-intl.com/TrailerLit
Available Hendrickson documentation can be viewed or
downloaded from this site.

3. Support the trailer with jack stands to prevent
possible damage to the equipment or injury if
slippage from the jack should occur.

All Hendrickson online documentation is in PDF format
that requires PDF reader software to open. A free
application is downloadable from Adobe at http://get.
adobe.com/reader/.

4. Remove wheels from both ends of the axle to be
replaced.
5. Remove brake components as needed.

Other related literature may include:
NAME
B31

Torque Specifications

L551

Shock Absorber Inspection Procedures

L578

Preventive Maintenance Guide

L579

Alignment Procedures

L583

Comprehensive Warranty Statement

L635

INTRAAX Shock Mount Assembly Procedure

L974

A. For drum brakes, remove drums and hub
assembly according to manufacturer’s
documented procedures. If Hendrickson, refer
to applicable literature listed online at www.
Hendrickson-intl.com/TrailerLit Brake & Wheelend Components.

DESCRIPTION

NOTE: Retract the brakes to remove the brake drum.
Follow the brake chamber manufacturer’s
procedure and cautions for manual brake
chamber release.

®

Drum Brake Maintenance Procedures

T12007

Technical Procedure General Safety Precautions and
Information

T71004

Hub and Rotor Assembly, Caliper Mounting

B. For ADB, remove brake calipers at both
ends of the axle. See Hendrickson literature
number T71004 and ADB manufacturer’s
documentation for more details.

Table 1: Related literature

Hendrickson reserves the right to make changes and
improvements to its products and publications at any
time.

NOTE: Vendor documents are listed at
www.Hendrickson-intl.com/TrailerLit.
2

L533 A

Axle/Beam Weldment Replacement Procedures
6. Perform these steps if the Height Control Valve
(HCV) is mounted on the affected axle: (If not
applicable, skip to Step C.)

Brake chamber

Spline inner
washers

Spline
retaining ring

A. Record the position of the HCV control arm so
it can be properly rotated into position after the
new HALFTRAAX is installed.
Retaining
ring

DO NOT
DISASSEMBLE

Slack
adjuster

Brake chamber
push rod

Axle in
Jounce

Clevis

S-cam journal washer
Figure 2: Brake chamber clevis

7. If exchanging brake chambers and slack
adjusters:

HCV

A. Remove the cotter and clevis pins from the
brake chamber clevis at the slack adjusters
(Figure 2).

Lower linkage
connection to beam,
bracket or band
clamp. If connected to
bracket, disassemble
from bracket.

B. Remove slack adjuster and mounting hardware
(Figure 2, shaded) from the camshaft using the
procedure outlined in Hendrickson literature
number L974, heading S-CAM REPLACEMENT
PROCEDURES. Discard used brake hardware.

Figure 1: HCV linkage lower connection

B. Remove HCV linkage (Figure 1) from the lower
connection only. DO NOT disassemble linkage.

IMPORTANT: Removing camshafts and camshaft
hardware is optional after the affected
axle assembly has been removed from
the trailer.

NOTE: If the HCV linkage is connected to a lower
bracket, the bracket will be removed when
applicable component fasteners are removed.
In this case, disconnecting the linkage from the
bracket is optional.

NOTE: Hendrickson recommends the use of new
hardware when installing camshafts.

If the lower bracket is a band clamp, care must
be taken to relocate the clamp at the same
location and rotation on the new HALFTRAAX
axle. Ride height may need to be readjusted
after installing the new HALFTRAAX. Refer to
Hendrickson literature number L459 Checking
Trailer Ride Height.
C. If exchanging drum brake shoes, remove
both sets of brake shoes using the procedure
outlined in Hendrickson literature number L974,
heading BRAKE SHOE REMOVAL - ALL MODELS.
Discard used brake hardware.

Figure 3: Brake chamber

NOTICE: Hendrickson recommends the use
of new mounting hardware when
installing brake shoes.

L533 A

8. If replacing brake chambers, remove the air lines
from the brake chambers (Figure 3) and plug the
lines to prevent contaminants from entering the air
system.
3

Axle/Beam Weldment Replacement Procedures 
CAUTION: DO NOT remove air lines from brake
chambers if system air is being used.
Component damage or personal
injury could occur.

AANT

NOTE: Removal of the air lines is not required if the
brake chambers can be stored out of the way.
Brake chambers should not be allowed to hang
from the air lines.

AANL

AAT

AANLS

9. Remove brake chambers by removing the nuts from
the mounting studs (Figure 3). If applicable, retain
HCV lower bracket for later reinstallation.
10. Use a floor jack, or equivalent, to raise the affected
axle assembly.

Figure 5: Sample lower shock mount hardware

CAUTION: Care must be taken when raising and
lowering the jack. The axle is attached
at the pivot joint, which tends to move
on the jack while being raised or
lowered. Caution should be exercised
to ensure the HALFTRAAX assembly
does not slip off the jack, causing
component damage or injury.

12. Remove lower shock mounting hardware (Figure 5)
to disconnect shocks from the beams.
NOTE: Removing shocks from the trailer is not
mandatory. The shocks are only required to be
disconnected from the suspension beams. They
may hang from the frame brackets until the
new HALFTRAAX® is installed. See Hendrickson
literature numbers L551 Shock Absorber
Inspection and L635 INTRAAX® Shock Mount
Assembly.

Lower air
spring
mounting
hardware
varies with
suspension
type

13. Lower and remove the floor jack(s). The end of the
suspension beams should rest on the surface.
14. Using a floor jack, or equivalent, support affected
axle assembly beams.
CAUTION: After pivot bolts and alignment
collars are removed, the suspension
beams are free to drop out of
the frame brackets. Support the
suspension beams during pivot bolt
removal to prevent personal injury or
damage to components.

Figure 4: Air spring bottom fastener(s)

11. Remove the air spring lower mounting nut from the
suspension beams (Figure 4). If applicable, retain
HCV lower bracket for later reinstallation.

15. Remove the pivot connection. Refer to Hendrickson
literature number L579 Alignment Procedure.
NOTE: L579 will also be referenced for pivot
connection reassembly and axle alignment.

NOTE: Removal of the air springs from the trailer is not
required.

16. Remove and save the alignment collars for reuse.
17. Remove suspension beams from the frame
brackets. It may be necessary to pry down on
suspension beams at the pivot connection until
they are clear of the frame brackets. Discard wear
pads.
4

L533 A

Axle/Beam Weldment Replacement Procedures
18. Removal of the affected axle is complete. Check
frame brackets and trailer sub-frame for damage if
the suspension was involved in an accident. Repair
or replace defective material.

INSTALL HALFTRAAX®
1. Clean and inspect reusable parts (hubs, drums,
lining. etc.) for wear or damage. Repair as needed.
NOTE: Where applicable, Hendrickson recommends
use of new brake shoe mounting kits, camshaft
kits and QUIK-ALIGN® pivot bolts.

Figure 8: HTRAAX in frame bracket

Figure 6: Bushing tube spacer installation

6. Carefully guide the suspension beams and wear
pads into the frame bracket (Figure 8). The masking
tape (Figure 6) may remain on the wear pads
during installation.

2. Using masking tape, attach wear pads to the pivot
bushings (Figure 6). The tape will hold the wear
pads in place during reassembly.

7. Line up the holes in the bushings with the
alignment slots in the frame brackets.

Figure 7: New HALFTRAAX™ secured to transmission jack

3. Position a jack, preferably a transmission jack,
under the center of the HALFTRAAX (Figure 7).
Secure the HALFTRAAX to the jack if possible. Move
the assembly into an installation position under the
trailer.

Figure 9: Installing new pivot connection hardware

8. Reinstall new pivot connection hardware for both
sides (Figure 9). Refer to Hendrickson literature
number L579 Alignment Procedure.

4. Raise the HALFTRAAX assembly with the jack and
attach shock absorbers to suspension beams using
new mounting hardware (Figure 5).

NOTICE: DO NOT over tighten the pivot joint
hardware, ensure the hardened
washers are free to spin.

5. Torque bolts to specifications listed in Hendrickson
literature number B31.

L533 A

9. Guide the air spring bottom mounting studs into
the mounting brackets on the suspension beams
(Figure 4).
5

Axle/Beam Weldment Replacement Procedures 
10. Install lower air spring nut and, if applicable, HCV
lower bracket.
11. Torque nut to specifications listed in Hendrickson
literature number B31.
NOTE: The transmission jack can be replaced with a
floor jack for the remaining operations.
12. Install applicable brake components. Care must be
taken to follow all notes, cautions and warnings.

Clevis

A. If drum brakes, follow procedures in
Hendrickson literature number L974.

Slack
adjuster

B. If ADB, follow procedures in Hendrickson
literature number T71004 and ADB
manufacturer’s documentation for more details.

Clevis pin
Pushrod

IMPORTANT: If ADB, the hub and rotor are installed
before brake components.

Cotter pin

Brake chamber

13. Install hubs and brake drums using the component
manufacturer’s installation procedures. Adjust
the wheel bearing using the procedure in the
applicable wheel-end manual.

Figure 10: Brake chamber/slack adjuster connection

18. Attach the clevis of the brake chamber pushrod to
the slack adjuster using the clevis pin (Figure 10).

14. Mount the brake chamber on the mounting bracket
(Figure 3). If applicable, install HCV lower bracket.

19. Install cotter pin in the clevis pin.
20. Attach HCV linkage to HCV lower bracket or mount.

15. Torque nuts to specifications listed in Hendrickson
literature number B31.

IMPORTANT: Adjustment of the height control
valve linkage may be necessary
after installation of the HALFTRAAX is
completed.

16. If used, remove and store the brake chamber
release tool following the brake chamber
manufacturer’s procedure. The brake chamber
manufacturer’s warnings and cautions must be
observed.

21. Install tires and wheels.
22. Adjust slack adjusters following the slack adjuster
manufacturer’s adjustment procedure.

17. If removed, install the brake chamber air lines and
tighten the fittings.

23. Lower axle assembly and remove the jack.

CAUTION: DO NOT use thread tape on fittings in
the air system. Contamination of the
air system could occur.

24. Align trailer following the procedure in Hendrickson
literature number L579 Alignment Procedures.

6

L533 A

Axle/Beam Weldment Replacement Procedures

Figure 11: Trailer connections

25. Complete final checks of the suspension and
brake system by supplying air to the trailer
(Figure 11).
26. Inflate air springs and check:
A. For air leaks.
B. Ride height, adjust if necessary. Refer to
Hendrickson literature number L459 Checking
Trailer Ride Height.
C. Fluid level in wheel-end hubs.
D. Ensure pivot joints are tight and the TORQRITE nuts are sheared. Refer to Hendrickson
literature number L579 Alignment Procedure.
27. Road test the trailer and check for proper brake and
suspension operation.
28. Check for air and fluid leaks.
For assistance in the United States and Canada, call
Hendrickson Trailer Technical Services at 866‑RIDEAIR
(743‑3247) or e-mail HTTS@Hendrickson-intl.com

L533 A

7

Call Hendrickson at 866.RIDEAIR (743.3247) for additional information.

www.hendrickson-intl.com

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 Canada
250 Chrysler Drive, Unit #3
Brampton, ON Canada L6S 6B6
800.668.5360
905.789.1030 • Fax 905.789.1033

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

L533 Rev A 12-18 ECN #####
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.

©2018 Hendrickson USA, L.L.C. All Rights Reserved

Printed in United States of America