Fashionable cars and trucks use helical gears and synchromesh units from the gearboxes, that synchronize the rotation of gears which have been going to mesh. This gets rid of clashing of the gears and will make gear shifting less complicated. It was initially introduced in 1939 for automobiles. It https://gearbox86308.blazingblog.com/33825465/the-gearbox-diaries