A new truck air suspension system has been developed which provides excellent roll stability and articulation capability without compromising the exceptionally soft ride characteristics of air suspension. The concurrent realization of roll stability and articulation capability for tandem driving axles has been achieved by designing a semirigid, roll-resisting, rear rear axle, to be used in conjunction with a freely articulating, forward rear axle. This principle applies equally well for single driving axle vehicles, where the rigid axle provides the same roll stability and articulation, not really a problem on single axle vehicles, is provided by frame and front axle suspension flexibility.
The new suspension was designed to fit vehicle models ranging 23,000-54,000 lb gvw, and a saddle arrangement was developed to attach the rear axle housing to the trailing arm. Aluminum forgings were used in an effort to achieve minimum weight in every suspension part and all chassis components.