The Hy-Drive was a Chrysler Corporation semi-automatic transmission introduced in 1953 in US-market Plymouths.
[1] It was a hybrid manual transmission equipped with a torque converter, like an automatic.
Once underway, the driver could upshift and downshift using the gear shift without using the clutch or even lifting off the accelerator.
The industry was caught by surprise by the advent of the automatic transmission in the early-to-late-1940s.
[4]) Chrysler had previously offered a Fluid Drive fluid coupling (not a torque converter, as it did not multiply the torque) on their manual transmissions, and the Hy-Drive was an evolution of this.