Dual Wheel Trucks (Dually)
A dual wheel vehicle, or “dually,” has four tires on the rear axle instead of only two for increased load capacity.
Benefits of a Dual Wheel
Dual wheel vehicles are ideal for towing and hauling heavy loads for an extended period of time. They provide even distribution of the vehilces load and can increase traction in most driving conditions. The majority of these vehicles are equipped with diesel engines for low end torque to provide smooth transitions and shifting.
Dual wheel Tire Maintenance
Tire maintenance is important for safety, and this is especially true with dual wheel vehicles. One of the most critical aspects of your "dually" tires is the spacing of the rear dual wheels and the distance between the sidewalls of the rear tires. When dual tires are under a load they deflect outward. If they deflect too much, due to either under inflation or overloading, the tires can touch sidewalls leading to serious tire damage. We recommend checking your air pressure at least once a month in order to maintain proper dual wheel spacing and to help prevent tire damage.
Dual Wheel Tire Sizing and Tread Depth
It is critical that dual tires be of the same size and tread depth to ensure the weight is ditributed evenly across all four tires. If the tires are different heights, the taller tire has to carry the majority of the load which can lead to premature wear or complete tire failure.
Dual Wheel Tire Rotations
Regular tire rotations will help prevent uneven wear and ensure the tires are of the same tread depth. The air pressure should be set to the vehicle specifications for each tire, including the spare, and adjusted to account for any additional towing/load requirements.
Installing Dual Wheels
The front and inside rear wheels have extremely positive offsets. The outside rear wheels will have an extremely negative offset. The rear wheels are then mounted face-to-face allowing the spacing required for the dual wheel application.
Some Dual wheels will have a locator pin to help with installation. This pin ensures that the wheels are lined up correctly to enable access to both inner and outer valve stems to add/remove air as needed.
The inner dual wheel will be installed first. The additional hole in the wheel should be lined up with the locator pin for proper alignment.
The outer wheel will be flipped opposite of the inner wheel. The locator pin should allow the valve stem location on the wheels to be 180 degrees from each other to allow easy access. In some applications, a flexible metal valve stem extension will be required to allow easier access to the valve stems.
The completed installation of the dual wheels should have the locator pin lined up with both the inner and outer wheels and the valve stems should be accessible. Before installing the lug nuts to fasten the wheels, be sure to check for this alignment and accessibility.
Aftermarket Wheels for a Dually
Lots of drivers like the aggressive look of aftermarket wheels on their trucks. If you decide to step up the style on your dually truck with aftermarket dual wheels, here are some things to keep in mind.
Because it’s so important to maintain load capacity, tire/wheel width, and dual wheel spacing, there are typically fewer aftermarket dually wheel options.
It’s important to make sure that the new tires are of a compatible width. If the tires are too wide, the dual wheel spacing can be impacted, which can lead to serious tire damage. If your new tires are too wide for their wheels, they will likely develop irregular wear.
Many aftermarket dually wheels can’t be rotated from their position on the vehicle. This means that a full tire rotation requires that all six tires and wheels be dismounted, remounted, and rebalanced. This can increase the time and cost it takes to do simple maintenance, and it’s something to think about before moving forward with a new set of tires and wheels on your dual wheel truck.