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| Illustration 1 | g01319495 |
Basic diagram for the power train systems | |
The power train is made up of three basic systems. The following systems are the three systems:
- Power Train Electronic Control Module
- Torque Converter
- Planetary and Transmission
The three basic systems have a hydraulic connection, an electrical connection, a magnetic connection, or a mechanical connection.
Power is supplied from the engine to the torque converter. Power goes from the torque converter to the transmission. If the transmission is in gear power flows from the transmission to the output shaft.
The operation of the power train begins at the Power Train Electronic Control Module (Power Train ECM). The Power Train ECM receives information from the selected speed of operation through sensors in the electrical system. The Power Train ECM uses the information from sensors in the electrical system to control the torque converter and the transmission hydraulic system.
The rotating housing of the torque converter is fastened directly to the engine flywheel. The torque converter has a lockup clutch for direct drive and a one-way clutch for torque converter drive. During torque converter drive, the torque converter drives the transmission hydraulically. During direct drive, there is a direct connection between the engine flywheel and the transmission.
The Power Train ECM will activate the lockup clutch solenoid when direct drive is necessary. When the lockup clutch solenoid is activated, the lockup clutch is hydraulically engaged. The lockup clutch becomes a direct connection between the rotating housing and the output shaft of the torque converter. The full power from the engine flywheel is transmitted through the torque converter when the torque converter is in direct drive.
The output shaft of the torque converter is connected to the transmission.
The Power Train ECM will activate the appropriate ECPC valves when shifts are needed. These valves engage the correct transmission clutches. The transmission clutches mechanically connect the transmission input shaft to the output shaft.
The transmission has seven forward speeds. The selection of the desired speed is done manually.
When the transmission is in a forward gear, the torque converter will be in either torque converter drive or direct drive. This is dependent on load factors, output speed of the torque converter and output speed of the transmission. The torque converter will be in torque converter drive for a short time during transmission shifts. This provides smoother engagement of the transmission clutches.
The torque converter hydraulic system uses oil that is also common with the transmission hydraulic system. These systems use the same section of the transmission case.
Some of the components in the torque converter hydraulic system include a torque converter inlet relief valve, a gear pump, a torque converter hydraulic filter, and a torque converter lockup clutch.
The pressurized oil that will engage the lockup clutch comes from the transmission section of the gear pump to the transmission oil filter. Oil flows through the transmission oil filter. Some of the oil is sent to the transmission hydraulic control and some of the oil will be sent to the torque converter lockup clutch. When the torque converter lockup clutch and synchronizing valve gets a pressure signal from the lockup solenoid, pump oil from the gear pump will be sent through the torque converter lockup clutch. This oil engages the torque converter lockup clutch.
Oil from the torque converter charge pump section goes through the torque converter hydraulic filter. The oil goes through the torque converter inlet relief valve and into the torque converter. Oil exits the torque converter and flows through the lubrication relief valve. The oil flows from the lubrication relief valve to the planetary.
Components of the transmission hydraulic system include a transmission hydraulic control, a transmission gear pump, a transmission hydraulic filter, a transmission magnetic screen, and a transmission oil cooler.
The transmission charging section of the transmission gear pump sends oil through the transmission hydraulic filter. The oil from the transmission charge pump section then goes to the transmission hydraulic control. The basic components of the transmission hydraulic control are the ECPC valves and the pressure control valve. This oil also supplies the lockup clutch solenoid.
The pressure control valve sends oil at the correct rate so that the correct clutches in the transmission are engaged smoothly.