摘要 |
A method of controlling a torque-transmitting mechanism in a multi-speed transmission includes providing structure forming a pressurizable reaction chamber at a reaction surface of an apply piston opposing an apply surface of the piston. The reaction chamber is pressurized to a first pressure during engagement of the torque-transmitting mechanism to establish a first speed ratio and a first torque capacity. The reaction chamber is pressurized to a second pressure level during engagement of the torque-transmitting mechanism to establish a second speed ratio and a second torque capacity. Thus, because pressure in the reaction chamber may be controllably varied, a greater reaction pressure is established during the second speed ratio, allowing a greater apply pressure level to be used to establish the second torque capacity. A clutch capacity control system is also provided that allows better control of torque-transmitting mechanisms engagable in different speed ratios to establish different torque capacities.
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