Twin-Traction Beam (TTB) is an independent suspension system for front drive axles in four-wheel drive Ford F-Series trucks and sport utility vehicles.
Twin-Traction Beam was invented by John A. Richardson and Donald G. Wheatley of Ford Motor Company covered by US patent 3,948,337 issued April 6, 1976. The patent name was “Independent front suspension for front-wheel drive” which was assigned to Ford Motor Company.[1][2]
The Dana Holding Corporation manufactured the TTB axle for Ford. It uses a universal joint in the center that allows the wheels to move independently of each other. The differential is offset to the driver's side, and a slip yoke is used on the long axle side to allow the shaft to change length. The TTB axles are variations of the Dana 28, Dana 35, Dana 44, and Dana 50.[3]
Common applications include: