Kenworth introduces new light-weight suspension

Kenworth Truck has announced the introduction of the AG380 lightweight air suspension. The new suspension can be spec’d on Kenworth’s complete Class 8 line of over-the-road tractors for highway applications – up to 80,000 lb (GCW) – with full production slated for June.

The suspension weighs about 650 lb fully installed, or 200 to 400 lb less than the trailing arm suspensions typically used on other Class 8 trucks. In addition, the Kenworth AG380 is lighter than most 4-spring suspensions.

Kenworth made extensive efforts to ensure that the new suspension would provide truckers with a stable ride and good handling. Jim Bechtold, Kenworth’s chief engineer, noted that the AG380 received over two years of extensive ride, handling, stability and durability testing on the road and in the lab before being brought to market.

“We know that a stable ride and good handling are essential to customers, so we got them involved in the testing process,” he said. “We had 13 customer units in the field, producing over 4 million miles of actual service data along with extremely valuable customer feedback.”

The AG380’s key components also underwent the equivalent of 6 million miles of road service during rigorous quality testing conducted in the lab at the PACCAR Technical Center.

To increase reliability, Kenworth engineers designed the AG380 with about half the parts of other truck suspensions. In addition, the new suspension is maintenance free with no lubrication points, Bechtold said, adding the suspension is the industry’s first use of 64-inch taperleaf springs and composite springs.

“During this project, we found that the traditional trailing arm suspension isn’t a structurally efficient way to utilize the stiffness of the axle housing for roll stability,” he said. “Instead, we used a smaller elliptic spring in the front end connected to a stiff, but lightweight, aluminum beam. This combination is more structurally efficient than a trailing arm spring and weighs a lot less. The result is a lighter and more structurally robust suspension for our customers.”