So this 1 set of gears can create all these distinct gear ratios without needing to interact or disengage every other gears. The handbook valve is just what the change lever hooks up to. Determined by which equipment is chosen, the handbook valve feeds hydraulic circuits that inhibit certain gears. https://gearbox-auto86306.blog-eye.com/34279484/the-basic-principles-of-gearbox-auto