Abstract: In a hydraulically actuated friction clutch or brake for an automatic transmission, contact between a pressure plate and retaining ring, each drivably engaged with an axially spline, is located at radialy outer position on the retaining ring, either because the adjacent surface of the pressure plate is relieved to produce contact at that location or because the retaining ring has a lateral surface that is relieved locally or tapered away from the surface of the retaining ring. Bending through the thickness of the component in which the spline teeth engage the pressure plate and retaining ring is reduced because the reaction force is applied to that component closer to the neutral axis than if contact between the pressure plate and retaining ring were distributed over a greater radial dimension of the retaining ring.