The very first automotive application in the lock-up theory was Packard's Ultramatic transmission, launched in 1949, which locked up the converter at cruising speeds, unlocking in the event the throttle was floored for fast acceleration or as the motor vehicle slowed. The lifespan of a failing torque converter is unpredictable. https://torqueconverterclutch82692.theideasblog.com/34468545/torque-converter-clutch-for-dummies