Torque Converter Clutch Application

Prerequisite: Read "Intro to the Torque Converter Clutch"

The clutch in a lockup torque converter is quite a bit different from any "typical" clutch seen in other applications. It is made up of a spring steel, with clutch lining on the outer diameter of one face, that mates with a corresponding "flat spot" on the inside of the torque converter housing. The torque converter housing is directly bolted to the engine flexplate (some people call it the flywheel), so it is obvious that the converter housing turns at exactly engine speed. The spring steel clutch is splined to input shaft (it is actually splined to the turbine, which is then splined to the input shaft), so it is also obvious that the clutch turns at exactly turbine, or transmission input shaft speed.

Fluid enters the torque converter through the input shaft, where it is "dumped" in behind the spring steel clutch, inbetween the clutch, and the converter cover, creating a highpressure area behind the clutch, forcing the clutch to spring away from the converter cover, and keeping the converter "unlocked". Fluid then enters the rest of the converter, leaking past the "gap" between the clutch, and the cover and does its normal job within the "pump", "turbine", and "stator", before exiting through the hub, and on to the cooler passage.

When conditions are right for a "lockup" to occur, fluid is reversed, by the lockup valve; Fluid enters the converter through the hub area, does it's job within the "pump", "turbine", and "stator", and creates a high pressure area on the opposite side of the clutch, forcing the clutch against the converter cover. The clutch material "grabs" the converter cover; The clutch, which is splined to the input shaft, becomes "one" with the converter cover, allowing no slippage between the two; .....lockup.

More to come.........