Steering shaft lock function on both sides so that the rotating shaft on both sides.Make the transmission from the engine to the wheels.By the time the wheels the other side free.
Acting lock the drive shaft on both sides. The two shafts rotate simultaneously to transmit power from the engine to the wheels more efficiently by the free wheel side.
A lock drive shaft on both sides. To make the shaft on both sides to rotate at the same time for power transmission from the engine to the wheels with more effective as other free wheel