The Constellation 5800 is typically employed in concrete mixer, heavy dump,crane and utility applications, as well as a concrete block truck. The new twin steer option features a 40,000-pound combined rating for the twin front steer axles and provides a maximum GVW of 86,000 pounds.
"The twin-steer factory option is great news for Constellation 5800 customers," said John Merrifield, senior vice president of sales and marketing for Sterling Truck Corporation and Western Star Trucks. "By incorporating twin-steer on the Western Star assembly line, we can maintain truck integrity, offer full warranty and service and ensure the truck, suspension and front axles combine to provide top performance and maximum up-time."
According to Merrifield, the new configuration features a 50-inch setback to the first steer axle with an 86-inch setback to the center of the steer tandem. This configuration--in combination with the 5800's short BBC--provides exceptionally good weight transfer and allows more operator payload. A 72-inch spread between the steer axles is perfectly matched to the cabin door position to allow for simple and safe entry and exit from the cab.
With the new twin-steer option, Western Star has optimized the steering geometry so the linkages of the steering arms match the suspension movement. This eliminates road 'kick-back' through the steering wheel and extends tire life by minimizing bump steer and tire scrubbing.
The steering system incorporates the latest in Sheppard M110 steering gears via a master gear, a slave gear and two linear assist cylinders, providing power steering at all four wheels and reducing stress in the steering linkage and axle steering arms.
Both front axles and the steering system are tuned to provide optimal steering performance. Western Star's proprietary shackle four-spring suspension is incorporated into the front axle design for lower maintenance costs and light weight performance.
With the addition of this twin-steer option, three twin-steer configurations are now available for Constellation models: the new 109-inch BBC with a 50-inch setback for the Constellation 5800 SS; the 109-inch BBC with a 33-inch axle forward for the Constellation 4800 FX; and the 123-inch BBC with a 50-inch setback for the Constellation 4900 SX.