Auxiliary Axle

The axle is rated based on the lowest capacity component fitted to that axle.  As an example; running certain single tire and rim combinations on an axle with a Trailer type spindle, for example, an ‘N’ or ‘P’ spindle, can significantly reduce the rating approved by the hub manufacturer.  The installer should check that the tire and rim combination meets the load requirements.  The rating information on the Hendrickson vendor provided hubs can be found at:

For KIC wheel ends (standard fit):
www.kic-group.com/pdf/KIC_Tech_010913.pdf

For Conmet wheel ends (optional):
www.conmet.com/pdfs/bulletins/10009934-RevF-12142011.pdf
 

A non-steerable lift axle that is not raised when turning, especially in a tight corner, will scrub concrete and impose high lateral stress on the wheels and chassis components of your vehicle. Raising the fixed axle when cornering will help decrease tire wear, reduce maintenance costs, and ensure proper functionality of the auxiliary lift axle when in use.

It is also important to be aware of the regulations within the states that your vehicle will operate in. Some state authorities prefer the auxiliary lift axles stay lowered and in operation when turning OR that the auxiliary controls remain outside of the vehicles cab. In these cases, it may be best to specify a steerable auxiliary lift axle for your vehicle.
 

The COMPOSILITE brand consists of both steer and non-steer lift axles with a two piece fabricated axle system. This axle system with integrated brakes allows for ease of use and maintenance with common components for both steer and non-steer single tire applications.

The TOUGHLIFT brand boasts Hendrickson’s round tube axle concept for rigorous environments in both steer and non-steer applications. This proven fully integrated axle system increases rigidity and is perfect for heavy duty on- and off-road single or dual-tire applications.

Hendrickson Specialty Products – Auxiliary Axle Systems would like to remind you that it is important for our customers to implement the recommended preventative maintenance (PM) into their regularly scheduled PM intervals to ensure optimal performance of their auxiliary axles. 

See the table below for quick look at our recommended PM schedules and Warranty Program.

 8AM – 5PM EST at 800-660-2829

Steer axle installation guide (H633)
Non-steer axle installation guide (H621)

 Application ride height is calculated by taking the loaded vehicle frame to ground measurement and subtracting the loaded tire radius of the selected lift axle tire. The difference will be the Application ride height.

If the loaded frame to ground dimension cannot be obtained, then the application “sag” (primary suspension deflection spec plus 1” for primary tire deflection) can be subtracted from the unloaded measurement, giving a reasonable approximation of the loaded measurement.
See illustration below:



Ex: 30” loaded frame to ground – 17” loaded tire radius = 13” application ride height

This would translate to a 12.5” Auxiliary Axle ride height (rounded down to maximize under tire ground clearance)

Determine any legal requirements and regulations in the area the vehicle is running

Fill out and return a copy of the H750 - Truck Spec Guide, H764 -Trailer Spec Guide,  or H722 - Loose Axle Spec Guide and contact [H] CS with any questions

8AM – 5PM EST at 800-660-2829