A clutch includes a carrier defining an annular groove and a hub coaxial with the carrier and defining an outer surface. The hub is axially movable relative to the carrier between at least a first position and a second position. A wedge disk has a first edge disposed on the outer surface, a second edge disposed in the annular groove, and a face extending between the edges and defining an annular shoulder. The disk engages between the carrier and the hub when the hub is in the first position to lock the clutch, and the carrier and the hub are rotatable relative to each other when the hub is in the second position. An annular retainer is configured to prevent radial expansion of the disk when the hub is in the second position and to permit radial expansion of the disk when the hub is in the first position.