Pressurized differential valve

A hydraulic valve means for controlling a differential clutch comprising a control valve including a valve element adapted for selectively connecting and disconnecting a source of pressurized fluid to a differential clutch, means defining a sump chamber in said hydraulic valve means adapted for connection to sump, means defining a control chamber in said control valve, a spring means in said control chamber normally biasing said valve element for interruption of communication between said source of pressurized fluid and said differential clutch, a relay valve including a valve member for selectively providing communication and interrupting of communication between said source of pressurized fluid and said control chamber, resilient means normally biasing said valve member of said relay valve to a position providing communication between said source of pressurized fluid and said control chamber, means defining a hydraulic actuator defining an actuating chamber in said relay valve adapted for connection to a hydraulic brake system, said hydraulc actuating chamber receiving pressurized fluid to interrupt communication between said source of pressurized fluid and said control chamber against the force of said resilient means when said hydraulic brakes are actuated, said resilient means biasing said valve member of said relay valve for providing communication between said source of pressurized fluid and said control chamber for pressure biasing said control valve element to provide communication between the said source of pressurized fluid and said differential clutch when said brakes are released.