The Purpose and Benefits of Adding a Trailer Lift Axle

August 29, 2022

What is a Trailer Lift Axle?

You might have seen a trailer lift axle and not even realized what you were looking at. Common on heavy haulers, semi-trucks, and flatbeds, this extra set of wheels is doing a big job--part-time. Where normally you would see two or even four sets of dual-wheeled axles while another set of wheels is just hanging in the air, inches from the ground, these wheels aren't just there for show or a nifty way of having a spare around. A trailer lift axle also referred to as a pusher or a tag axle, is there to assist in weight distribution, especially in the heavy haul industry.


Most often, you'll see them on sand trucks, flatbeds, or heavy equipment lowboy trailers. It works by having an extra set (or many) of axles with dual wheels that can be raised or lowered with the help of a pneumatic airbag controlled by the driver. The axle is dropped into place and locked there by air pressure in the trailer's air ride suspension system. Some trailer lift axles can be operated manually with a mechanical lift system. We carry an assortment of trailer lift axles of both varieties.

What is the Purpose of Lift Axles?

In the heavy-haul industry, trailers have to handle a lot of weight. All of that weight has to ride on a trailer, which has to distribute that weight under load to the road. Many roads and bridges aren't rated for excessive weight unless the tractor and trailer hauling the weight come within the proper rating by having enough axles to distribute the weight. For example, an 80,000 lb load on only four sets of wheels puts a lot of pressure onto a limited surface area. This kind of pressure, on a bridge or a country road, might have the same effect as an 80,000 lb pizza cutter over time rather than rubber tires. Adding lift axles allows for more weight to be evenly distributed across a larger surface area.

Benefits of Trailer Lift Axles

Not only is it better for the roads and bridges, but having lift axles also benefits the truck, trailer, and other equipment. Here are some of the ways having a lift axle (or many) can benefit your trucking experience.


  • Smoother ride: Having an extra set of tires underneath the trailer can make a big difference in how smooth a trailer rides, especially on unpaved roads. This helps to better stabilize freight and keep it from shifting or, in the case of transporting heavy equipment, falling off the trailer entirely.
  • Heavier loads: With more tires and axles underneath a heavy load, the weight is better distributed throughout the trailer on the surface of the road. This reduces the forces exerted on the tires and allows for an incredible amount of weight to ride on a trailer. Weight limit laws vary from state to state, and transporting material across state lines might require different displacement. Failure to comply with the law could result in fines for the driver or the company.
  • Fuel economy: When not in use, the extra axles can be raised out of position, thus reducing the drag the trailer has on the road. With less drag, less horsepower is required to move the trailer down the road, and less fuel needs to be used to make up the difference. Truck drivers who pay for their own fuel can already appreciate the savings at the pump a lift axle can give them.
  • Less wear and tear on trailer: Reducing wear and tear with lift axles works in two different ways. Under a heavy load, the weight is distributed throughout the system and relieves a lot of the pressure on the tires, axles, wheels, and suspension overall. When not in use, the axle can be raised, and that tread isn't making contact with the road any longer, reducing wear on tires as well as the stress on the motor hauling everything.
  • Easier on the roads: Again, having the lift axle lowered and assisting the other wheels reduces the impact on the road, which could be very bad under heavy weight. Without the added weight, the axle is lifted out of position, and less surface area comes into contact with the road, saving the asphalt from additional friction.
  • Reduced tolls: Some states allow for lower tolls on vehicles using fewer axles on the roads and bridges. This is to encourage trucks to be outfitted with equipment that helps prolong the life of the highway and interstate infrastructure.

Contact Cush Suspensions

If you would like to learn more about how you can outfit your trailers, lowboys, heavy haulers, flatbeds, and other freight hauling equipment with a trailer lift axle, contact us. You'll immediately see the difference, and your drivers will thank you for the improvement on the ride.

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