Abstract: A mechanism for controlling the direction of flow of concrete from the discharge opening of a concrete mixing drum, preferably mounted on a vehicle having a chassis with a cab at the front end wherein the discharge opening of the mixing drum is adjacent the cab. The apparatus includes a rigid support frame with a collecting hopper rigidly mounted on the frame adjacent the discharge opening of the mixing drum for receiving concrete flowing through the discharge opening of the mixing drum. An outlet is provided in the hopper for the discharge of concrete therethrough. A bearing is mounted around the outlet. A driven gear is rotatably carried by the bearing for movement in a substantially horizontal plane about a substantially upright axis. An elongated discharge chute is pivotally carried by the driven gear for movement with the driven gear for movement about a horizontal axis and is positioned for receiving concrete flowing through the outlet of the hopper.