Along with the 3-passage torque converter, two passages are employed for transmission oil (ATF) flow from the torque converter and for clutch cooling, even though the third passage is utilised independently to control the lock and unlock with the clutch. For vehicle homeowners encountering troubles with their torque converter clutch, https://torqueconverterclutch86396.thezenweb.com/torque-converter-clutch-for-dummies-72281934