Paccar is adding a new proprietary front axle for a range of Kenworth and Peterbilt vocational vehicles in the third quarter of 2017. The new 20,000- and 22,000-lb wide track steer axles are designed for applications such as construction, refuse and heavy-haul.
The steer axle is available with standard front air disc brakes or optional drum brakes as well as suspensions and wheel end options to meet the demanding applications. Both axle ratings will be available in a range of trucks including the flagship models Kenworth T880 and Peterbilt 567. Other Peterbilt models include the 520, 389, 367, 365, 348 and the 389 glider kit.
“The idea for Paccar to investigate a new proprietary front axle started in 2013. We utilized our Paccar engineering teams in both North America and Europe in the development of a heavy front axle to meet the North American market demands,” a Paccar spokeswoman told Truck & Off-Highway Engineering.
The new axle “uses an innovative tapered kingpin roller bearing, which simplifies the design and delivers enhanced steering efficiency,” Landon Sproull, Paccar vice president, said in a statement. Sproull is currently serving as SAE’s Commercial Vehicle Sector vice president as well (http://articles.sae.org/15169/).
A steering angle of up to 50 degrees is possible, depending on size of tires and wheel offset.
“The tapered kingpin design improves the strength in the axle by eliminating the need for draw pins. The roller bearings ensure smooth movement of the axle knuckle for better steering performance over typical bushings,” the spokeswoman said.
The design also offers a weight-savings benefit compared to previous axles—up to 23 lb (10 kg), according to Paccar spokesman Ken Hastings. “Every pound counts in the trucking world, especially for heavy loads—the lighter the truck, the more [payload] the truck can carry since you're limited by weight,” he told TOHE.
The main benefit of the axle, according to Hastings, is that it's qualified to Paccar's rigorous validation requirements, which enhances vehicle uptime for customers. He relayed the following information about how the new front axle was tested:
"Testing was developed using data recorded from the most harsh vocational applications. Every component was individually validated as well as the complete axle assembly on multiple truck durability, fatigue and lab tests exceeding the recorded loads from each of the vocational applications targeted for this new axle."
Validation testing took place at Paccar's technical center in Mount Vernon, WA. The front axle has a five-year or 750,000-mile warranty.