Abstract: A transmission actuator has gear steps for forming gears and a selector shaft supported rotatably for shifting gears and supported axially movably for selecting gears. The actuator has a gate with a fixed first gate part and an axially movable and rotatable second gate part, the one gate part having slots and lands alternating in a direction and the other gate part having at least one element which can interact with one of the lands at a time and is movable into one of the slots at a time. The element is moved in a prescribed direction past the lands and slots in a selecting motion and is moved into one of the slots in a shifting motion. When there is a collision between element and land during a shifting motion the movable gate part can be moved further in the prescribed direction of the selecting motion by an insertion chamfer and when there is a the movable gate part is not movable contrary to the prescribed direction of the selecting motion, but the shifting motion is stopped.