When spec'ing a truck or tractor with lift axles, it is important to consider the following: lift axle location, weight needed to be supported by the lift axle and lift axle regulator location. These variables will affect how the chassis is evaluated for both Frame and Creep review. If the frame or axles are not capable of withstanding the payload, the chassis will receive lower axle ratings (de-rating). Some options to avoid this are selecting a bigger frame rail size, adding an insert, or relocating the loads. In some instances, relocating the lift axle controls outside of the cab will allow the frame to be approved for your application. In other instances, a more extensive review may be required.
When in doubt, you can always send a spec and detailed body drawing to firstname.lastname@example.org for an in depth analysis. This can take the guess work out and eliminate future potential required changes once the order is in. Whatever the case may be for your order, the Sales Engineering team can help you through any lift axle questions that may arise.
Another thing to consider when spec’ing lift axles is bridge law. Keep in mind that each state has different requirements and lift axle spacing needs to be double checked to make sure the spec will be legal for your area of operation. While sales engineering can be a great resource for working through this, the responsibility ultimately falls on the dealer to make sure that the spec is in compliance with local and federal laws.