Trailer Lift Axle
For trailers that spend a significant portion of their life with light loads, empty back hauls or diminishing load delivery applications, a lift axle can be utilized for a variety of benefits.
Introduction & Rationale
Lift axles have long been part of dump truck specs and have been growing in use on 6×2 chassis configurations. They are also now being seen on dry van trailers as well. Air pressure on the trailer suspension non-lift axle air bags operates the system automatically.
Several manufacturers have suspensions that will work for this application.
Eliminate the rolling resistance of one axle’s tires when empty or lightly loaded
The tractor is designed to have weight on the gear set, so lifting the front trailer axle puts more weight on the rear of the tractor. This minimizes tire slip and makes the gear set more efficient.
Reduced Tire Wear
Tire life of the lift axle’s tires is enhanced by reduced use when lifted: both due to normal rolling and due to scrub during turns. The trailer tires remaining on the ground also have better wear since they have an optimized trailer footprint.
Brake life of the lift axle is enhanced when it is not loaded and the other axle has better wear with the proper tire footprint.
Reduced Toll Costs
If the axle is not touching the ground, some tolling points will not charge for that axle. Kansas, Oklahoma, Florida, and Illinois are just some of the states where this can happen.
Although booth attendants will be able to see the lifted axle in daylight, don’t expect all of them to believe you in the dark of night. This feature is not that common yet. If using automated tolling, the benefit of a lifted axle may not be possible if the system cannot detect it.
Slightly higher than normal, especially since air ride suspensions are more expensive than spring rides.
Axle flex & roll stability
If you plan to run the single axle up to its weight rating, it is worth discussing whether a higher rating is better for your application.
What Others Are Saying
Joel Morrow, Ploger: “We added trailer lift axles for NACFE’s Run On Less demonstration and our experience with them has been very positive with no obvious downsides.”
Watson & Chalin