Abstract: A supporting structure for control elements of an automatic transmission including a multiple-disc clutch having a piston operated by hydraulic pressure from a control valve unit and a cylinder slidably supporting the piston, and a one-way clutch having outer and inner races and a series of sprags placed between both of the races so as to mechanically jam depending on the rotational direction of the outer race, comprises a support member comprised of the cylinder and the inner race which are integrally formed with each other, and a transmission case for fixing the support member on the inner surface thereof from the inside of the transmission case by means of bolts.

Abstract: An automatic power transmission includes a clutch drum integrally connected with an one-way clutch which is fixed to a support secured on a transmission casing so that each one bearing is required for supporting the clutch drum and the one-way clutch. A sun gear is also supported by means of a single bearing and is integrally formed with a spline which is loosely engageable with a spline of the clutch drum so that the radial force may not act in the spline engagement while an engine output torque is transmitted therethrough.