So this one list of gears can produce most of these various equipment ratios without needing to have interaction or disengage another gears. The guide valve is what the shift lever hooks up to. Depending on which equipment is chosen, the handbook valve feeds hydraulic circuits that inhibit certain gears. https://gearboxauto97395.ivasdesign.com/55612331/gearbox-auto-things-to-know-before-you-buy