With a standard open diff.... If one of the four wheels loses traction, lets say the right rear, the rear differential senses this as less resistance and makes that wheel spin. A spinning wheel does not move the vehicle. The other wheel on the same axle (on firm ground with plenty of traction) gets the same amount of torque as the spinning wheel. Not much. Both wheels together do not produce enough torque to move the car. A differential always distributes torque equally. The amount of torque generated at the wheel with the least traction determines how much the other wheel will get - the same amount of very little. Little torque because traction is low at the spinning wheel.
Click the pic for a better view.
Limited Slip Differentials, the name says it all, they limit wheel slip. The Trac-Lok transmits equal torque to both wheels when driving straight. However, when one wheel spins due to loss of traction, a patch of ice, mud, too much throttle, etc., then the unit automatically provides more power to the wheel that has traction. Highly effective for daily driving and works well in rain, mud and snow.
Our Jeep Liberty limited slip is driven by a series of clutch disc located behind the side gears. The discs are held under tension with springs. As the slip increases the tension increases between the different layers of disc and provides resistance to limit the slip between the wheels.
Our limited slip is an ideal choice for those who want better traction, but feel that a locker is a little too extreme for their needs. Its a good balance between a useless stock open differential (in slippery or lifted tire situations), and a full-time locked differential. This is the same unit which would have come from the dealership in your Jeep if it had the new factory limited slip option... only for HUNDREDS less!