Mechanical limited slip differentials are arguably the most common type of differential due to their wide range of applications. They work by shifting a portion of the torque to the wheel with the most traction while limiting the slip on the wheel with the least traction. Because of this, limited slip differentials are often referred to as “torque sensing”.
Like an open differential, the wheels can rotate at different speeds. However, with a limited slip differential, torque is not always balanced between the wheels. This allows the wheel with traction to receive more torque in order to continue to move the vehicle. In other words, the differential is said to “bias” more torque to the higher traction tire. The amount of torque variation the differential can shift between wheels is referred to as the bias of the differential.
Eaton makes two types of limited slip differentials: the Eaton Posi (positraction) and the Detroit Truetrac.