Positive Traction Differentials: Description

Positive traction type differential that directs major driving force to wheel with greatest amount of traction. This is accomplished by a spring loaded multiple disc clutch pack behind each side gear. Each clutch pack uses friction surfaced clutch discs splined to the side gear and steel clutch plates held by the differential case. The only major difference in the designs is the type of preload spring used.

The Eaton design uses 4 coil springs held by a spring retainer plate located between the side gears. The Dana design incorporates a Belleville type spring behind each side gear. The G.M. design employs a single "S" shaped spring located between the side gears to provide outward pressure on the gear and clutch pack assembly.

In operation, the preload spring pressure is accompanied by the side gear thrust load to compress the clutch packs providing resistance to normal differential action. Preload spring pressure is calibrated to allow some slippage of the clutch packs under variable torque conditions (turning corners, etc.). All designs use a 2 pinion, single piece case assembly.