Modern cars use helical gears and synchromesh units during the gearboxes, that synchronize the rotation of gears that happen to be going to mesh. This gets rid of clashing with the gears and can make gear shifting less difficult. Spur and helical gears are Utilized in the sliding mesh https://jeffreyobjtd.ampedpages.com/not-known-factual-statements-about-gearbox-60774667