Present day autos use helical gears and synchromesh units inside the gearboxes, that synchronize the rotation of gears which have been about to mesh. This eliminates clashing in the gears and helps make gear shifting simpler. It had been first launched in 1939 for cars. It is made up https://sethhkmmk.pages10.com/the-basic-principles-of-gearbox-69158165