In the event of sliding mesh gearbox, the output shaft gears continually rotate with the output shaft though in other gearbox, the output shaft gears are mounted with bearings that's why these gears rotates separately. Dual-clutch automatic gearboxes commenced to appear in street autos in 2003, notably in the Audi https://gearbox-auto87306.answerblogs.com/34005930/the-basic-principles-of-gearbox-auto