Using the 3-passage torque converter, two passages are useful for transmission oil (ATF) flow with the torque converter and for clutch cooling, although the third passage is employed independently to regulate the lock and unlock on the clutch. The torque converter clutch is usually a cornerstone of contemporary automatic transmission https://torque-converter-clutch41889.blogdigy.com/the-best-side-of-torque-converter-clutch-51321854