In this kind of gearbox, each of the gears of the primary shaft are in regular mesh with the corresponding gears from the countershaft (layshaft). Because the figure shows, two sliding Pet dog clutches are provided on the primary shaft. A device need to be licensed to enable the engine crankshaft https://zaneuvsoi.blogsuperapp.com/34716443/little-known-facts-about-automobile-gearbox