Locking differentials have a different variation from a standard car differential. The difference is increased traction versus the open or standard differential, which is accomplished by restricting each of the axle wheels to the same rotation speed.
Locked differentials are useful for off-road vehicles since they have the same parts as open ones but the hydraulic, pneumatic, and electricmechanisms offer uniqueness because they lock output pinions together. A switch activated manually puts any of these mechanisms in use locking both wheels at the same speed, regardless of whether one wheel is on the ground or not.
An unlocked differential or open differential would give each of the two wheels the ability to rotate at different speeds thus avoiding any type of tire scuffing which would be an advantage during turns. Each wheel on the axle would have the same torque or rotational force even if rotating at different speeds or even if one tire isn’t rotating at all.
An automatic locker differential locks and unlocks with no help at all from the driver. This type of differential guarantees engine power to each wheel no matter whether there is traction or not, and unlocks under certain conditions say if a wheel needs to rotate faster than the other which is true during turns.
An example of this is the Detroit Locker which replaces the differential carrier assembly entirely. There is also what’s referred to as the lunchbox locker which replaces an internal spider gear and shaft with interlocking plates. Both of these auto lockers will allow for a variate wheel speed while cornering, but otherwise lock both shaft axles when and if traction conditions demand it to do so.
The selectable locker is yet another type of locked differential allowing the driver to lock and unlock at any time from the driver seat. This happens through the use of compressed air or pneumatics, and cable devices. With these components the differential can be locked and unlocked whenever necessary.
Race cars use locking differentials for constant traction mainly during high speed turns and maneuvers as well as fast acceleration. Heavyequipment vehicles like forklifts, tow trucks, tractors and the like would also use this type of differential mainly for traction on soft uneven surfaces.