Abstract: A control system, for a rotating clutch having a rotating housing with a cavity adapted to axially slidably receive a clutch actuating piston therein and defining a clutch actuating chamber therebetween, includes a source of fluid, a control valve for infinitely variably supplying the fluid through a path in the housing to the actuating chamber so that the actuating piston is biased in a direction to engage the clutch, a plurality of passages in the housing disposed in fluid communication with the actuating chamber and the path, and including a fluid exhaust passage connecting therewith, and a differentially sensitive centrifugal valve slidably disposed in the passages for relieving fluid from the actuating chamber to the exhaust passage in response to centrifugal force and to fluid pressure in the actuating chamber, and in opposition to fluid pressure in the path in a differential area ratio responsive manner.