Hence, gearbox is necessary to regulate output velocity & torque. According to the necessity in the vehicle, we could accomplish distinctive speeds or torque with the assistance of a gearbox. The final Motors Hydra-Matic turned the main mass-generated automatic transmission following its introduction in 1939 (1940 product 12 months). Available https://lanedqwdd.techionblog.com/34175232/the-5-second-trick-for-gearbox-auto