General Description

This transmission is a fully automatic unit consisting primarily of a three-element hydraulic torque converter and a compound planetary gear set, see image. Three multiple disc clutches, a roller clutch and a band provide the friction elements required to obtain the desired function of the compound planetary gear set The compound planetary gear set provides three forward speeds and reverse.

The torque converter couples the engine to the planetary gears through oil and provides torque multiplication. It consists of a pump or driving member, a turbine or driven member and a stator assembly. The stator is mounted on a one-way roller clutch which allows the stator to turn clockwise but not counterclockwise.

The torque converter housing is filled with oil and rotates at engine speed. The converter pump is an integral part of the converter housing, therefore the pump blades rotating at engine speed set the oil within the converter into motion and direct it to the turbine causing the turbine to rotate. As the oil passes through the turbine it travels in such a direction that if it were not redirected by the stator it would strike the rear of the converter pump blades and impede its pumping action. Therefore at low turbine speeds, the oil is redirected by the stator to the converter pump in such a manner that it actually assists the converter pump to deliver power or multiply engine torque. As turbine speed increases, the direction of the oil leaving the turbine changes and flows against the rear side of the stator vanes in a clockwise direction. Since the stator is now impeding the smooth flow of oil, its roller clutch releases and it revolves freely on its shaft. Once the stator becomes inactive, there is no further multiplication of torque within the converter. At this point the converter is acting as a fluid coupling since the converter pump and turbine are being driven at about the same speed, or at a one-to-one ratio.

The hydraulic system in this transmission is pressurized by a gear type pump to provide the working pressures required to operate the friction elements and automatic controls.





The 180C transmission is the same in operation as the 180 with the addition of a torque converter lock-up clutch. It is a fully automatic unit consisting primarily of a four element hydraulic torque converter and a compound planetary gear set, see image.

Three multiple disc clutches, a roller clutch, and a band provide the friction elements required to obtain the desired function of the compound planetary gear set.