Dually Axles

What is a dually axle?

chevrolet dually rear axle

 

Since you are researching dually axles, you probably already know what dually rear

axles are but just in case there is any confusion, a dually axle has two pairs of rear wheels totalling six wheels on the vehicle. They are also often abbreviated as DRW meaning ‘dual-rear-wheel’.

How do you identify a dually axle?

A dually is easy to identify given the additional rear wheel on either side of the axle adding to the overall width of the vehicle. This commonly means that when installed on a vehicle, the rear fenders are larger in order to accommodate covering the extra wheels.

dually rear axle with large fenders

What is the benefit of a dually axle?

Dually axles have a number of benefits primarily related to load endurance. The additon of extra wheels on either side of the axle provide additonal contact with the road helping spread the weight across a wider area. In doing so, less pressure is concentrated on a single wheel and transferred to a narrower road surface. Additionally, this provides increased stability and balance due to the additonal axle width, plus, additional traction due to the extra surface contact.

Another design characteristic is the makes the axle what is termed full floating meaning the vehicles weight is not carried on the axle but instead, is placed on the bearing hubs at the outer ends of the axle. This makes the axle more robust than axles deisgns where the vehicle weight is carried by the axle.

Why get a vehicle equipped with a dually axle?

Dually axles tend to have a higher payload than axles with single wheels. The actual payload capacity depends on the brand but as an example, the 3500HD DRW from chevrolet (in 2020), increased the payload 2215 lbs over the standard 3500HD single wheel axle.

Vehicles with dually axle carrying heavy equipment

Additional benefits include the optional use of a gooseneck towing attachment (fifth-wheel attachement point) in the bed of the vehicle above the axle which improves the max towing capacity ability of the vehicle.

With additional towing capacity, comes the need for additional braking ability. Dually axles often come with upgraded brakes to help stop the heavier loads.

What are vehicles with dually axles used for?

Due to the large towing capacity and payload capacity, vehicles with a dually axle can be used for a much larger variety of tasts than their single wheel alternatives. Where they are ideal for industrial/commercial applications, they are also ideally suited for recreational purposes such as RV trailer hauling, horse boxes, boat trailers and ATVs  for example.

RV being hauled on a dually axle

With such a variety of abilities, one of the biggest benefits is the peace of mind that that just about any towing or payload task can be handled using a vehicle equipped with a dual wheel axle.

What are the disadvantages of a dually axle?

If you are considering getting a vehcile with a dually axle, the first major difference you will notice is the cost. A dually vehicle will cost thousands more than a single rear wheel vehicle.

Due to the additional weight of the axle, frictional losses and extra contact with the road surface, operating costs (fuel efficiency) for a vehicle with a DRW axle are increased.

Vehicles equipped with dual rear wheels are less comfortable than their single wheel counterpart.

The most obvious disadvantage of a DRW vehicle is the cost to replace 2 additional tires.

Should I buy a dually?

If you are happy to live with the disadvantages listed above and require the benefits of having a dually, then you should buy a dually. Having confidence in your vehicle to achieve the task at hand is always worthwhile.

What dually axle options are available?

Unlike the variety of models of pickup trucks available these days, there are a much more limited variety of dually vehicles available. However, each of the major american vehicle manufacturers offers a dually version fo their pickup truck. These include:

  • Ford F-350 Super Duty and F-450 Super Duty
  • GMC Sierra 3500HD
  • Dodge Ram 3500HD
  • Chevrolet Silverado 3500HD

Which to choose is your choice. To make your choice, keep these variables in mind for your purposes:

  • Payload Capacity
  • Towing Capacity

These two factors vary among the different manufacturers and may be a factor in your final choice. Nothing beats a test drive of course!