• Single source for comprehensive technical support,
training and warranty
* Contact your local Hendrickson representative for complete warranty
terms, conditions and limitations

INTRAAX Top-mount
®

AANT 23K

The definitive system for weight-conscious haulers
• Application: Straight-frame platforms, container chassis, liquid tankers,
bulk tankers, bottom dumps, grain and livestock trailers
• Capacity: 23,000 pounds
• Ride heights: 12 to 19 inches
• Trims an average of 50 pounds from what was already the lightest,
toughest integrated suspension-axle-brake system
• Tapered hanger design allows installation without additional gussets on
trailer frames as narrow as four-inches, giving improved installation efficiency
• Standard LDA™ Large-Diameter Axle provides heavy-duty performance from an ultra-light axle

INTRAAX Top-mount
AAT 23K • 25K • 30K

Reducing weight, improving ride, minimizing maintenance
and maximizing productivity
• Application: Ideal for platforms, tankers, dumps and loggers
• Capacities: 23 • 25 • 30,000 pounds*
• Ride heights: 13.5 to 19 inches
• Standard LDA™ Large-Diameter provides heavy-duty
performance from an ultra-light axle
• Lightest in its class
* Axle capacity 25,000 pounds

32

AIR SUSPENSIONS
INTRAAX Low-ride / Liftable
®

AANL 23K • AAL 23K • 25K • 30K

Designed specifically for low-ride heights and liftable axles
• Application: Ideal for configurations including platforms, dumps,
drop-decks, tankers, B-trains, livestock trailers and specialty trailers
• Capacities: 23 • 25 • 30,000 pounds*
• Ride heights: 6.5 to 19 inches (AAL)
6.5 to 17 inches (AANL)
• Lightest integrated liftable system available
• Compact UBL™ UNDER BEAM LIFT™ allows for closer axle spacing
• Standard LDA™ Large-Diameter Axle provides heavy-duty
performance from an ultra-light axle
* Axle capacity 25,000 pounds

INTRAAX Extreme-duty
AAEDT / AAEDL 30K

INTRAAX AAEDT

Extreme-duty top-mount and low-ride systems provide the muscle
needed for toughest off-road and heavy-hauling applications
• Application: Raw wood trailers including loggers and chip vans; dumps,
tankers, straight- and drop-deck platforms and specialty trailers
• Capacity: 30,000 pounds — suspension and axle
• Ride heights: Top-mount, 14 to 17 inches / low-ride, 9 to 19 inches
• The first integrated 30,000 pound structural and axle capacity system for severe-duty
and heavy-hauling operations
• Low-pressure air springs with steel pistons and full bottom plate coverage
• High-damping, extended-service shock absorbers
• Heavy-duty options include rear-mount shock absorbers and chain down-stops
INTRAAX AAEDL

INTRAAX Compact Low-ride
AANLS 20K

Brings advantages of system integration in a highly compact,
low-ride height suspension
• Application: Auto haulers, moving vans and drop frame trailers
• Capacity: 20,000 pounds*
• Ride heights: 6.25 to 12 inches
• Compact package ideal for the tight confines of the auto hauler and drop-frame
trailer designs
• System accepts 15- or 16.5-inch brakes allowing choice of 19.5- to 24.5-inch tires
• Air suspension package more than 120 pounds per axle lighter than comparable suspensions
* Axle capacity 25,000 pounds

UNDERSTANDING AIR SUSPENSIONS

33

TRAILER

UNDERSTANDING

Suspensions

Self-Steer

Benefits
• Standard with RTR® READY-TO-ROLL® wheel-end
packages

• QUIK-ALIGN® pivot connection — helps simplify axle
alignment

• Available with TIREMAAX® automatic tire inflation
systems

• TRI-FUNCTIONAL® bushings — proven technology
for mile after mile of trouble-free service

CONNEX -ST
™

Trailer self-steer suspension system
•
•
•
•
•

Application: Ideal for multi-axle trailer applications
Capacity: 25,000 lbs.
Ride heights: 14 to 19 inches
Assists with compliance of Ontario SPIF regulations
Helps increase maneuverability

CONNEX

™

CXU 23K / 25K
Unitized Air Suspension and Axle System
• Application: Low-ride height applications that require
12.25-inch drum brake package
• Capacities: 23,000 and 25,000 lbs.
• Ride heights: 5.5 to 6.5 inches
• Galvanized frame bracket option for bolt-on
frame brackets

34

AIR SUSPENSIONS

35

UNDERSTANDING

Common Components of an
Integrated Air Suspension System
SHOCK ABSORBER

FRAME BRACKET

PIVOT CONNECTION

BEAM ASSEMBLY

BRAKE SYSTEM
AIR SPRING

AXLE

CAM TUBE

Standard Terminology
Air Spring Terminology
AIR SPRING: An inflatable bag designed to hold a volume
of air. Sometimes referred to as air bag. Supports the trailer
with air pressure.
FLEX MEMBER: Inflatable rubber portion of the air spring.
PISTON: Bottom portion of the air spring that attaches to
the flex member. Used to mount the air spring to the
suspension beam
BEAD PLATE: Mounting surface of the air spring that is
attached to the flex member.

Axle Terminology
AXLE TRACK: The lateral distance between the center of
the dual tires on an axle.
HN SPINDLE: Similar to the D22 or TN spindle. A tapered
spindle with small outer wheel bearings and large inner
wheel bearings.
HP SPINDLE: Similar to the P22 or TP spindle. A straight
spindle with the same inner and outer wheel bearings.
36

LDA™ LARGE-DIAMETER AXLE: Replaced typical 5-inch
axle with a 5.75-inch diameter.

Beam Terminology
BEAM ASSEMBLY: Sometimes referred to as walking beams
or trailing arms. Load carrying structure that pivots at the
frame bracket, connects to the axle tube and the air spring.
“Y” BEAM: Suspension beam assembly that straddles the
trailer frame at the pivot.

Frame Bracket Terminology
FRAME BRACKET: Sometimes referred to as hangers, towers
or support boxes. Load carrying structure that bolts or welds
to the trailer frame and attaches to the beam assembly at the
pivot connection.
WINGED FRAME BRACKET: A frame bracket with an integral
gusset on the inside rear surface for lateral support.
WINGLESS FRAME BRACKET: A frame bracket that does not
include an integral gusset. Typically uses a separate 3-inch
C-channel to provide lateral support.

AIR SUSPENSIONS
WELD-ON FRAME BRACKET: A frame bracket that welds
to a steel trailer frame.
BOLT-ON FRAME BRACKET: A frame bracket with holes in
the top plate for bolting to an aluminum frame.
WELDABLE BOLT-ON FRAME BRACKET: A frame bracket
that bolts to an aluminum frame using OEM provided
mounting plate.

Hendrickson Product Terminology
T SERIES: Hendrickson’s first trailer suspension products.
Offered in various capacities and configurations.
HT™ SERIES: Hendrickson’s improvement on the T model;
similar capacities and configurations.
CONNEX™-ST: Trailer s elf-steer suspension system.

General Terminology

INTRAAX®: Hendrickson’s integrated axle, beam assembly
and brake system.

RIDE HEIGHT: Distance from the center of the axle to the
mounting surface of the suspension (bottom of trailer frame
or slider frame) at normal operating position.

INTRAAX®-SP: A durable and low maintenance slider system
designed specifically for platform and drop-deck trailers.

JOUNCE: The maximum upward motion of the axle from ride
height toward the frame, including bumper compression.
REBOUND: The maximum amount of downward axle travel
allowed by the suspension; controlled by the shock absorber.
TOP MOUNT: A suspension where the beam assembly is
on top of the axle.
UNDERSLUNG: A suspension where the beam assembly
is under the axle.
TRI-FUNCTIONAL® BUSHING: Rubber bushing located in the
beam assembly of the pivot connection. Controls horizontal,
vertical and roll forces on the vehicle.
SHOCK STRAP: Strap that is mounted around the shock that
is used to provide additional strength for limiting rebound.
PIVOT BOLT: The bolt that attaches the beam assembly to
the frame bracket at the pivot connection.
WELDED ALIGNMENT: Suspension alignment connection
where the alignment is secured by welding.
QUIK-ALIGN®: Suspension alignment connection where the
alignment is adjusted using an eccentric alignment washer
and secured by torquing the pivot bolt­­.
LOADED TIRE RADIUS: The distance between the axle spindle
centerline and the ground when the vehicle is in its loaded
condition. Determined by the size and design of the tire.

VANTRAAX®: Air suspension slider systems. Marries our
superior K-2® slider box technology with the patented
INTRAAX integrated suspension / axle / brake system.
SURELOK®: A device used to maintain trailer deck height
during loading and unloading. Also used in place of a dump
valve to protect against trailer walk.
HEIGHT CONTROL VALVE: Sometimes referred to as a leveling
valve. An air valve that automatically responds to position of
the axle and vehicle frame. It maintains the distance from the
centerline of the axle to the underside of the frame ride height.
DUMP VALVE: Air dump or exhaust valve. Added to the trailer
suspension air system to exhaust the air from the
air suspensions and increase stability during loading and
unloading.
LIFT KIT: An air-operated mechanism that is used to raise
a trailer axle off of the ground.
BUSHING TOOL: Special tool used to remove and replace
the TRI-FUNCTIONAL® Bushing of a beam assembly.

Slider Terminology
SLIDER: Sometimes referred to as a bogie or subframe.
Movable suspension mounting used to reposition the
trailer axle(s).
BODY RAIL: Steel rail that is mounted to the trailer.
Contains holes that align with the slider locking pins.
MANUAL STOP BAR: A bar that is inserted into a set of
slider body rails that is used to stop the movement of the slider
while being repositioned.
LOCKING PIN: Pin within a slider box assembly that keeps
the slider from moving. Retracts to allow for the repositioning
of the slider.

UNDERSTANDING AIR SUSPENSIONS

37

UNDERSTANDING

Applications

Primary (Fixed) Suspension Application Guide
Converter
Dollies

Suspension

Category

Single
Axle
4

Van Type Trailers

Tandem
Axle
4

Van Type
Frt. Van
Refrig.
Van

Chip Van
Highway
Transport

Livestock

Platform
Trailer
Straight
Frame

Platform
Trailer
Drop
Frame

Curtain
side

Equipment
Trailer
Lowboy

Extendable
Tandem
Axle

Extendable
Multi-Axle

Container
Chassis

Logging
Chassis

Chart A For Highway Use, Good Paved Roads, Well Maintained Unpaved Roads

Model
AANT 23K

Drop
Frame
Van
Furniture
Van

Frame Type Trailers

R

R

O

R

R

R

R

R

AAT 23K
INTRAAX®
Top Mount

R

AAT 25K

R

AAT 30K
AAEDT 30K

R

AANLS 20K
AANL 23K
INTRAAX
Low Mount
or Liftable

O

O

O

O

O

R

O

O
O

AAL 23K

R

O

AAL 25K

O

AAL 30K
AAEDL 30K
CONNEX™
Underslung

CXU 23K

O

O

O

R

O

R

O

O

CXU 25K

O

O

O

R

O

R

O

O

HT190T
HT™ Series
Top Mount

HT230

O

HT Series
Liftable

O

O

O

O

O

O

O

HT300

O

HT250T

O
O

O

O

O

O