Positraction Differentials

A positraction differential is a special traction differential. Its purpose is to improve the way your differential performs under adverse conditions. When one wheel starts to slip, these differentials transfer the torque to the wheel that is not slipping. The car can then continue to go forward. There are several different kinds of positraction differentials, but all of them are based on a friction device to provide resistance to normal differential operation. A positraction differential provides better traction, which is handy when roads are slippery. It also lends itself to fast acceleration. One type uses four differential pinions instead of two, with two pinion shafts. It also uses a series of four clutch discs. The differential pinions run into resistance when they try to turn the axle side gears. The resistance gets transferred to the pinion shafts driving the pinions. The shafts are forced to slide up little ramps. This action moves both shafts outward. The pinions cause the clutches to lock. Other types use cone clutches, or disc clutches under pressure from coil springs. By restricting the differential action, torque is delivered to the slipping wheel.