HEAVY-DUTY VEHICLE FRAME

A primary frame for a heavy-duty vehicle includes a pair of spaced-apart, parallel, elongated and longitudinally extending main members. Each one of a pair of hangers is attached to and depends below a respective one of the main members. An axle/suspension system is mounted on the hangers. A vertically disposed brace structure extends between and is attached to the hangers or, alternatively, to both the hangers and the main members. The brace structure includes a hanger cross member disposed perpendicularly between the hangers and a pair of inclined members each of which extend between and are attached to the hanger cross member and a respective one of the main members or an upper wing of a respective one of the hangers. The brace structure efficiently dissipates loads from the axle/suspension system into the primary frame adjacent the hangers and eliminates the need for additional cross members within the frame.