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| Illustration 1 | g00942979 |
Flow of Oil in the Torque Converter Drive. (1) Flywheel pilot (2) Rotating housing (3) Lockup clutch (4) Turbine (5) Impeller (6) Stator (7) Inlet passage for converter oil (8) Yoke (9) Hub (10) One-way clutch (11) Outlet passage for converter oil (12) Carrier (13) Output shaft | |
The torque converter consists of the following components:
- Rotating housing (2)
- Lockup clutch (3)
- Turbine (4)
- Impeller (5)
- Stator (6)
- One-way clutch (10)
The one-way clutch (10) holds stator (6) when the torque converter is used. The one-way clutch (10) allows stator (6) to turn freely when the torque converter is not used. In all FORWARD and REVERSE speeds, the operation of the lockup clutch is controlled by the Transmission Electronic Control Module (ECM). The transmission can be in either torque converter drive or direct drive in all FORWARD and REVERSE speeds.
The torque converter cover is fastened directly to the flywheel housing. The torque converter cover provides an oil reservoir and a location for two valves. Flywheel pilot (1), rotating housing (2), and impeller (5) are fastened together. Flywheel pilot (1), rotating housing (2), and impeller (5) are driven as a unit by the flywheel. Yoke (8) of output shaft (13) is connected to the upper drive shaft of the transfer case. Power is sent through the upper drive shaft to the transfer gears of the transmission.
One-Way Clutch
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| Illustration 2 | g00944644 |
Detail of One-Way Clutch (6) Stator (14) Cam (15) Rollers (16) Springs (17) Openings in cam (18) Carrier | |
Splines connect stator (6) to cam (14). Cam (14) is turned by the stator. Carrier (18) does not turn.
Rollers (15) are the mechanical connection between cam (14) and carrier (18). Rollers (15) are in openings (17) of cam (14). Springs (16) are also in openings (17). The left side of openings (17) are smaller than the right side of openings (17) because the opening has a taper. Normally, springs (16) retain rollers (15) in the taper at the left side of openings (17) .
When the speed of impeller (5) and turbine (4) is slow, stator (6) is held stationary. Rollers (15) are held in the taper of openings (17) by springs (16). There is a mechanical connection between cam (14) and carrier (18). Since carrier (18) is held stationary, cam (14) is held stationary. Since cam (14) can not turn, stator (6) does not turn. Stator (6) can deliver oil back to impeller (5) .
As the speed of impeller (5) and turbine (4) increases, stator (6) starts to turn in the same direction as impeller (5) and turbine (4). When the stator (6) starts to turn, cam (14) starts to turn. The movement of cam (14) causes rollers (15) to move from the tapers of openings (17). The mechanical connection between cam (14) and carrier (18) is broken. Stator (6) and cam (14) turn freely. Stator (6) does not deliver oil back to impeller (5) .
Lockup Clutch
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| Illustration 3 | g00944683 |
Oil Flow to the Lockup clutch (1) Flywheel pilot (2) Rotating housing (3) Lockup clutch (4) Turbine (5) Impeller (6) Stator (8) Yoke (9) Hub (10) One-way clutch (11) Outlet passage for converter oil (12) Carrier (13) Output shaft (19) Inlet passage (20) Piston (21) Plates (22) Discs (23) Plate | |
Lockup clutch (3) is part of the torque converter. Lockup clutch (3) is located between the engine flywheel and turbine (4). The lockup clutch is engaged as the output speed of the transmission increases in all FORWARD and REVERSE speeds. When the lockup clutch is engaged, impeller (5) and turbine (4) turn at the same speed as the engine and there is no loss of power in the torque converter. The connection between the engine and the transmission is now direct.
Rotating housing (2) is connected to the engine flywheel by splines. Rotating housing (2) is fastened to impeller (5) by bolts. Piston (20), plates (21) and plate (23) are also connected to rotating housing (2) by splines. Discs (22) and output shaft (13) are connected to hub (9) by splines. Turbine (4) is fastened to hub (9) .
Operation of the Lockup Clutch
The transmission electronic control module (ECM) activates the lockup clutch valve which sends pressure oil for operation to the lockup clutch. Oil from the lockup clutch valve goes through inlet passage (19) in carrier (12). The oil goes through a passage in the center of output shaft (13). The oil then goes through flywheel pilot (1) and rotating housing (2) to piston (20). The pressure of the oil causes piston (20) to move toward plate (23). This causes plates (21) and discs (22) to be held together. The plates and the discs turn at the same speed. The plates and discs become a direct connection between rotating housing (2) and output shaft (13). The machine is in direct drive.
When the lockup clutch is engaged the pressure sensor for the lockup clutch sends a signal to the transmission electronic control module (ECM). The transmission ECM controls the amount of pressure in the lockup clutch. This prevents spikes in the lockup clutch.
When the lockup clutch is not engaged, the operation of the torque converter is normal.
Direct Drive
Oil under pressure from the lockup clutch and solenoid valve causes lockup clutch (3) to engage. As the engine flywheel turns, lockup clutch (3) connects rotating housing (2) with hub (9). This causes turbine (4) and impeller (5) to turn at the same speed. Stator (6) turns freely. At this time, the torque converter is not in operation.
The flow of power is from rotating housing (2) through lockup clutch (3), hub (9) and output shaft (13). The power goes directly through the torque converter. The power then goes through the upper drive shaft to the transfer gears of the transmission.