Snow blowers with driver-selectable locking differential

Differential unlock

— the differential is found exclusively in self-propelled units; it is a mechanism that allows the drive wheels to rotate at different speeds when powered by the engine.

By default, the differential (if there is one at all) is locked, and both wheels have the same rotational speed. This has a positive effect on cross-country ability, but creates inconvenience when cornering: during a turn, the wheel on the outside must rotate faster than the wheel on the inside. Unlocking the differential eliminates this inconvenience. On the other hand, a relatively small and light snow blower can be deployed manually by disengaging the clutch and turning the unit on freely rotating wheels. Therefore, this function is provided only in powerful and heavy models, in which "manual" rotation is difficult.