A gearbox or even a transmission program within an automobile can be a machine which works by using various gears, shafts and actuating elements to transmit energy from motor on the wheels. For more more details, here is a detailed article on gearboxes or transmission systems used in automobiles. A few other gears like 1st speed, 2nd speed, https://automobile-gearbox08529.blogunteer.com/33128200/rumored-buzz-on-automobile-gearbox