what is differential lock

A locking differential is a mechanical component commonly used in vehicles to overcome the limitations of a standard open differential by essentially "locking" both wheels on an axle together as if on a common shaft. Locking differentials can lock the axles together to provide 100% of available torque to the wheel with traction, increasing traction by forcing both tires on an axle to rotate at the same speed. Locking differentials are considered essential equipment for serious off-road driving, and they are commonly used in agricultural equipment, military trucks, tow trucks, forklifts, tractors, and heavy equipment to maintain traction, especially when driving on soft, muddy, or uneven surfaces. Some farm tractors have a pedal that can be stepped on with the operators heel to lock the differential as needed. Four-wheel drive vehicles that drive off-road often use a locking differential to keep from getting stuck when driving on loose, muddy, or rocky terrain. Many such vehicles have a locking differential on the central differential (between the front and rear axles), rear differential and front differential, or any combination of any of the three. Differential locking can also be used in the sport of drifting as an alternative to a limited-slip differential.