Abstract: A transmission gear train has a clutch designed to minimize shift shock upon engagement while still exhibiting relatively rapid initial engagement. To this end, a face cavity is formed in the clutch actuating piston which acts as an accumulator into which hydraulic fluid flows for a period of time after initial clutch engagement. This fluid flow causes clutch pressure to be lower than system main pressure while the accumulator is filling, thereby providing a cushioning effect which reduces shift shock. Use of the accumulator or face cavity eliminates the need for a stepped piston and the additional seals and flow passages normally required for a stepped piston, thus simplifying clutch manufacture and operation.