AIR DIRECTIONAL CONTROL VALVE ( 4630630020 )

The Gearbox Valve has several functions & purposes & the valve body consists of a number of valves.

The valves are referred to by the shifts they are responsible for. For example, the third-fourth valve determines an upshift from third gear to fourth gear & the fourth-third is responsible for a downshift from fourth gear to third. Each valve is connected to a shifter in the vehicle. The manual valve is the one controlled by the driver.