Abstract: A multiple ratio automatic transmission control system for an automotive vehicle comprising a multiple ratio gear set and a simple planetary gear set arranged in series. The control system has multiple control modes including an automatic control mode in which upshifts and downshifts between adjacent ratios are achieved by engaging and releasing friction clutches and brakes in the simple planetary gear set and in the multiple ratio gear set and wherein a manual shift control mode includes a select-shift control. Engine braking is available in each gear for both operating modes. In the select-shift manual control mode, a particular gear can be chosen by the operator for continuous single-ratio operation. The control system includes variable force solenoids that are multiplexed in combination with pressure modulator valves for achieving each operating mode.

Abstract: A control valve system for a multiple ratio automatic transmission having a reaction brake for forward drive and a reaction brake for reverse drive. A first clutch establishes a driving connection between an input gear element and a torque input shaft establishes a forward drive torque flow path when the forward drive brake is engaged. A second clutch connects a different torque input gear element of the transmission to the torque input member when the reverse reaction brake is applied. A pressurized valve circuit with three variable force solenoids, including one variable force solenoid, establishes a controlled circuit pressure, a second variable force solenoid is dedicated for reverse engagement control and a third variable force solenoid is dedicated for forward engagement control, whereby independent reverse engagement pressures and independent forward engagement pressures on the clutches and brakes, are established.

Abstract: An automatic transmission having a multiple ratio gearset arranged in series with an overdrive gearset wherein ratio upshifts and downshifts are effected by separate reaction brakes for each gearset, each brake being independently controlled to achieve an enhancement of shift quality using closed loop control of reaction brake pressure and high ratio clutch pressure as a function of turbine speed, output shaft speed, brake drum speed for the multiple ratio gearset and input shaft speed in establishing control of upshifts and downshifts.

Abstract: A control system for engaging and releasing a torque converter bypass clutch and for varying the torque capacity of the clutch by adjusting the torque converter torus chamber pressure in accordance with changing operating variables, the bypass clutch including a clutch release pressure chamber that is maintained at a calibrated pressure threshold valve whereby pressure clutch capacity control is achieved by controlling pressure differential in the converter.

Abstract: Multiple-speed, hydrokinetic-mechanical change-speed gearbox controlled by an hydraulic control valve system for a motor vehicle comprising multiple ratio gearing and a simple planetary gear unit located between the hydrokinetic portion and the multiple ratio gearing.