Torque Converter - Description

DESCRIPTION










The torque converter is a hydraulic device that couples the engine crankshaft to the transmission. The torque converter consists of an outer shell with an lock-up damper (1), lock-up piston (3 ), pump impeller (4), turbine runner (5), stator (6), and one-way clutch (7). The converter clutch provides reduced engine speed and greater fuel economy when engaged. Clutch engagement also provides reduced transmission fluid temperatures.

The torque converter is a sealed, welded unit that is not repairable and is serviced as an assembly.

CAUTION: The torque converter must be replaced if a transmission failure resulted in large amounts of metal or fiber contamination in the fluid.


IMPELLER




Figure 2 - Impeller





The impeller (Figure 2) is an integral part of the converter housing. The impeller consists of curved blades placed radially along the inside of the housing on the transmission side of the converter. As the converter housing is rotated by the engine, so is the impeller, because they are one and the same and are the driving members of the system.

TURBINE




Figure 3 - Turbine





The turbine (Figure 3) is the output, or driven, member of the converter. The turbine is mounted within the housing opposite the impeller, but is not attached to the housing. The input shaft is inserted through the center of the impeller and splined into the turbine. The design of the turbine is similar to the impeller, except the blades of the turbine are curved in the opposite direction.

STATOR










The stator assembly (Figure 4) is mounted on a stationary shaft which is an integral part of the oil pump. The stator (1) is located between the impeller (2) and the turbine (4) within the torque converter case.

The stator contains an one-way clutch (1-4), which allows the stator to rotate only in a clockwise direction. When the stator is locked against the over-running clutch, the torque multiplication feature of the torque converter is operational.

Torque Converter Solenoid

In order to reduce heat build-up in the transmission, the TCM can turn on or off the Torque Converter Solenoid as needed. This function can occur at various times depending on the following variables:

- Shift lever position
- Current gear range
- Transmission fluid temperature
- Input speed
- Throttle angle
- Engine speed