A valve body for an automotive transmission includes a pressure regulator valve in the casting for controlling oil pressure within the torque converter. The valve has a bore to provide fluid communication with an exhaust circuitry in the transmission when the valve is moved by oil pressure from a first position to a second position. The regulator valve prevents excessive pressure and damage from ballooning of the torque converter housing. In an alternative non-lockup torque converter, a check ball in a modified separator plate moves to open and close an oil path in the plate to thereby control oil pressure.

A hydraulic control device includes: a pressure regulation valve that regulates a hydraulic pressure of oil supplied from an oil pump; a discharge oil passage through which the oil discharged from a fluid coupling flows when a lockup clutch is disengaged; a lubrication oil passage that supplies the oil from the discharge oil passage to a location to be lubricated; a return oil passage that returns the oil drained from the pressure regulation valve to a suction port of the oil pump; a connection oil passage that connects the lubrication oil passage and the return oil passage; and a flow direction regulation valve that is provided in the connection oil passage.

A valve body for an automotive transmission includes a pressure regulator valve in the casting for controlling oil pressure within the torque converter. The valve has a bore to provide fluid communication with an exhaust circuitry in the transmission when the valve is moved by oil pressure from a first position to a second position. The regulator valve prevents excessive pressure and damage from ballooning of the torque converter housing. In an alternative non-lockup torque converter, a check ball in a modified separator plate moves to open and close an oil path in the plate to thereby control oil pressure.

A transmission, includes a transmission mechanism including a torque converter having a lock-up clutch; an oil pump configured to discharge an oil to be supplied to the transmission mechanism; a lock-up oil pressure control valve configured to adjust a pressure of the oil discharged from the oil pump and supply the oil to the lock-up clutch; a lubricating oil pressure control valve configured to adjust the pressure of the oil discharged from the oil pump and supply the oil to a portion to be lubricated of the transmission mechanism; and a controller configured to control the lock-up oil pressure control valve. The controller controls the lock-up oil pressure control valve so that a precharge time when a lubricating oil pressure which is an oil pressure supplied from the lubricating oil pressure control valve is a first lubricating oil pressure becomes shorter than another precharge time when the lubricating oil pressure is a second lubricating oil pressure which is lower than the first lubricating oil pressure when performing a precharge of supplying the oil to the lock-up clutch.

A hydraulic control device includes: a pressure regulation valve that regulates a hydraulic pressure of oil supplied from an oil pump; a discharge oil passage through which the oil discharged from a fluid coupling flows when a lockup clutch is disengaged; a lubrication oil passage that supplies the oil from the discharge oil passage to a location to be lubricated; a return oil passage that returns the oil drained from the pressure regulation valve to a suction port of the oil pump; a connection oil passage that connects the lubrication oil passage and the return oil passage; and a flow direction regulation valve that is provided in the connection oil passage.

A hydraulic circuit supplies pressurized hydraulic fluid to and from a torque converter that is operatively associated with a lockup clutch. The torque converter is disposed upstream of an outlet regulator that maintains a predetermined pressure in the torque converter. Power transmission in a powertrain can be directed through the torque converter during a hydrodynamic mode and can be directed through the lockup clutch during lockup mode. To switch between the hydrodynamic mode and the lockup mode, the hydraulic circuit includes a diverter valve to selectively direct pressurized hydraulic fluid between the torque converter and the lockup clutch. When operating in the lockup mode, the diverter valve further diverts hydraulic fluid discharged for the torque converter to bypass the outlet regulator disposed downstream of the torque converter.

A hydraulic circuit supplies pressurized hydraulic fluid to and from a torque converter that is operatively associated with a lockup clutch. The torque converter is disposed upstream of an outlet regulator that maintains a predetermined pressure in the torque converter. Power transmission in a powertrain can be directed through the torque converter during a hydrodynamic mode and can be directed through the lockup clutch during lockup mode. To switch between the hydrodynamic mode and the lockup mode, the hydraulic circuit includes a diverter valve to selectively direct pressurized hydraulic fluid between the torque converter and the lockup clutch. When operating in the lockup mode, the diverter valve further diverts hydraulic fluid discharged for the torque converter to bypass the outlet regulator disposed downstream of the torque converter.

A hydraulic circuit supplies pressurized hydraulic fluid to and from a torque converter that is operatively associated with a lockup clutch. The torque converter is disposed upstream of an outlet regulator that maintains a predetermined pressure in the torque converter. Power transmission in a powertrain can be directed through the torque converter during a hydrodynamic mode and can be directed through the lockup clutch during lockup mode. To switch between the hydrodynamic mode and the lockup mode, the hydraulic circuit includes a diverter valve to selectively direct pressurized hydraulic fluid between the torque converter and the lockup clutch. When operating in the lockup mode, the diverter valve further diverts hydraulic fluid discharged for the torque converter to bypass the outlet regulator disposed downstream of the torque converter.

A hydraulic circuit supplies pressurized hydraulic fluid to and from a torque converter that is operatively associated with a lockup clutch. The torque converter is disposed upstream of an outlet regulator that maintains a predetermined pressure in the torque converter. Power transmission in a powertrain can be directed through the torque converter during a hydrodynamic mode and can be directed through the lockup clutch during lockup mode. To switch between the hydrodynamic mode and the lockup mode, the hydraulic circuit includes a diverter valve to selectively direct pressurized hydraulic fluid between the torque converter and the lockup clutch. When operating in the lockup mode, the diverter valve further diverts hydraulic fluid discharged for the torque converter to bypass the outlet regulator disposed downstream of the torque converter.

The hydraulic circuitry of the factory installed automotive automatic transmission of the General Motors Corporation identified as the Allison 1000 and 2000 Series is modified to include a new return spring to decrease clutch pressure and mainline pressure so as not to exceed a predetermined pressure to reduce the time to complete an upshift, to replace the main regulator valve spring to increase main line pressure at road speed based on road conditions, and to provide a new valve with an internal exhaust circuit operatively associated with the TCC (Torque Converter Clutch) to lower balance circuit pressure resulting in the increase of converter clutch apply pressure. The methods and systems for modifying the factory installed transmissions improve the overall operation and efficiency of the transmission during operation of the motor vehicles in which the transmissions are installed.