Maximize uptime and lower costs by choosing the right axle

Making the right decision when selecting an axle for your commercial vehicle can prevent expensive repairs, wear and tear, and unnecessary vehicle downtime. Whether you are a prospective customer, an end user, or a sales consultant, asking the right questions and knowing the terminology will ensure the longevity and best performance of your vehicle. This article will cover some factors to consider when specifying your vehicle’s axles, including vehicle weight, terrain, duty-cycle and suspensions.  

To learn more about the importance of properly specifying the right axle for your application, or to learn where to go for more information, click on the video.

Why asking the right questions matters

Not all axles are built the same. Choosing the correct axle for your application will help avoid costly downtime and repairs not covered under warranty. Similarly, an improperly spec’ed axle could fail under excessive strain. Just as you would not use the same bag for different tasks, you should not expect one type of axle to fit all commercial vehicles. The following are some of the most important things to consider when selecting your vehicle’s next axle and suspension.  

Gross Weight vs. Payload: What Should You Focus On? 

The weight of your vehicle is crucial in deciding on the right axle. There are two critical metrics to understand: 

• Gross Vehicle Weight (GVW): This is the total weight of the vehicle, including the payload, fully loaded. GVW includes the weight of the vehicle itself plus all cargo, fuel, fluids, passengers, and equipment. 
• Payload: This is the weight the vehicle is designed to carry, calculated by subtracting the curb weight (the weight of the vehicle without the load) from the GVW.

It is essential to consider the vehicle’s gross combination weight (GCW) to ensure the axle can manage the weight. GCW includes the total loaded weight of the truck and any trailers it may be pulling. Remember that the capacity of a tandem axle is not the same as the capacity per axle. 

By carefully considering both the gross vehicle weight and payload, you can avoid overloading the axles, which may lead to premature failure and costly downtime. 

What terrain will the vehicle encounter? 

The environment in which the vehicle will operate plays a critical role in choosing the right axle. Knowing the expected road conditions allows you to choose an axle that will offer optimal performance. 

Four common terrain classifications: 

1. Turnpike: Long stretches of smooth, paved roads with minimal stops. 
2. On-Highway: Pavement that may include occasional sharp turns, moderate stops, and starts. 
3. On-Highway Mountain: Steeper grades, sharp turns and extended braking intervals. 
4. Off-Highway: Unpaved, rough roads with higher rolling resistance.  

What suspension system works best with the axle? 

The vehicle suspension type is closely tied to how well your vehicle handles its load. Choosing the correct suspension for the axle is crucial for maintaining vehicle stability and reducing axle stress. 

• Reactive Suspension: This system induces high torsional loads, making it more suitable for rugged terrains and heavier loads.
• Non-Reactive Suspension: This system does not use the axle as a suspension element; instead, it relies on other components to absorb the load.

Matching these suspension systems specifically to the vehicle’s operational needs will prevent unnecessary wear and prolong the lifespan of your commercial vehicle.

What does this mean for you?

Choosing the proper axle does not need to be complicated. While there are several options to choose from, asking the right questions will help you determine the proper axle for your vehicle. Understanding the difference between payload and gross vehicle weight will limit premature failure and costly downtime.

• Road conditions, duty cycle and terrain are important when choosing the proper axle for optimal performance. This will reduce emissions and overload to your vehicle and limit unwanted repairs and maintenance.
• Compatibility with vehicle suspension is essential to vehicle load stabilization and reduces stress on the axles, preventing unnecessary wear and keeping you on the road.

Cummins' Drivetrain and Braking Systems offers solutions tailored to each application, including axles, brakes, drivelines, transfer cases and all purpose-built to ensure your vehicle stays on the road longer with optimal performance and lower costs. To learn more about the importance of adequately specifying the right axle for your application, watch the video accompanying this article. To learn more about Cummins’ industry-leading portfolio of drivetrain solutions, contact a Cummins DriveForce representative.