Present day automobiles use helical gears and synchromesh devices inside the gearboxes, that synchronize the rotation of gears which have been going to mesh. This eradicates clashing in the gears and would make equipment shifting easier. Examples of these types of transmissions are used in helicopters and wind turbines. https://connerfynbo.howeweb.com/34435167/gearbox-can-be-fun-for-anyone