The Intraax suspension system, manufactured by Hendrickson, is a popular air-ride suspension found on many heavy-duty trailers. Understanding its parts is essential for proper maintenance and repair. This guide provides a detailed intraax suspension parts list, describing each component and its function.
What Is the Intraax Suspension System?
Intraax is an integrated air-ride suspension and axle system that combines the suspension, axle, and brake components into a single unit. This design reduces weight and improves durability compared to separate systems. The main components include beams, air springs, shocks, torque rods, and a height control valve. Each part plays a critical role in ride quality, load support, and safety.
Complete Intraax Suspension Parts List
Beam Assembly
The beam is the primary structural member that connects the axle to the trailer frame. Intrrraax beams are typically made of high-strength steel and are designed to absorb road shocks. The beam includes welded-on axle seats and frame brackets. Over time, beams can crack or bend under extreme loads. Regular inspection for cracks or deformation is important.
Air Springs (Air Bags)
Air springs are the key components that provide ride height and load support. They are rubber bellows filled with compressed air. The Intraax system typically uses two air springs per axle. When the trailer is loaded, the air springs compress, and the height control valve adds air to maintain ride height. Air springs can develop leaks or punctures from debris. Visual inspection for cracks or sagging is recommended.
Shock Absorbers
Shocks dampen the oscillations of the springs, improving ride stability and tire wear. Intraax uses hydraulic shock absorbers mounted between the beam and frame. Worn shocks can cause excessive bouncing and poor handling. Signs include fluid leaks or reduced damping force. Shocks should be replaced in pairs.
Torque Rods
Torque rods control the fore-aft and lateral movement of the axle. They connect the axle to the frame and prevent axle wrap during braking and acceleration. Intraax systems typically have two upper and two lower torque rods per axle. The ends have bushings that wear over time. Loose or worn torque rods can cause misalignment and uneven tire wear.
Height Control Valve
This valve automatically adjusts the air pressure in the air springs to maintain a constant ride height, regardless of load. It is mounted on the frame and connected to a linkage on the axle. A malfunctioning height control valve can cause the ride height to be too high or too low, leading to poor handling or damage to other components.
Brake Components
Intraax integrates the brake system, including brake chambers, slack adjusters, and brake drums. The system uses S-cam air brakes. Components like brake shoes, drums, and chambers require regular inspection and replacement as part of routine brake maintenance. Worn brakes can affect stopping distance and safety.
Alignment Adjusters
Some Intraax models include alignment adjusters on the torque rods or other points to correct axle alignment. Proper alignment ensures even tire wear and tracking. Adjusters can seize from corrosion, so periodic lubrication is recommended.
Bushings and Fasteners
Bushings are used in torque rods, beam pivots, and shock absorber mounts. They are typically rubber or urethane and degrade over time. Worn bushings create play in the suspension, causing vague handling and noise. Fasteners, including bolts and nuts, must be torqued to specifications. Loose bolts can lead to component failure.
How to Identify the Right Parts for Your Intraax System
To order the correct replacement parts, you need the model number of your Intraax system (e.g., Intraax AA, Intraax AAL, etc.) and the axle capacity. The model number is stamped on a plate attached to the beam or frame. Also, check the specific part numbers for items like air springs and shocks, as they vary by application. Using OEM parts is recommended for compatibility and durability.
Maintenance Tips for Longevity
- Visual Inspections: Walk around your trailer and look for leaking air springs, damaged torque rod bushings, or cracked beams. Address issues immediately.
- Air System Checks: Test the height control valve by measuring ride height at load and unload. Correct if needed.
- Lubrication: Grease bushings and adjusters per the manufacturer's schedule.
- Torque Checks: Verify that all bolts are tight, especially after replacing components.
- Shock Replacement: Replace shocks every 100,000-150,000 miles or sooner if leaking.
- Brake Inspection: Include brake components in your regular maintenance routine.
Final Recommendation
Maintaining your Intraax suspension system requires knowing the parts and their functions. Always use OEM or reputable aftermarket parts that meet Hendrickson's specifications. If you are unsure about a repair, consult a qualified trailer technician. Regular inspections and prompt replacement of worn parts will keep your trailer riding smoothly and reliably.