The Tilton Flow Control Valve works by restricting the return flow of hydraulic fluid by a tunable amount, reducing shock loads to the driveline by allowing the clutch to slip slightly during engagement. It does not restrict flow during release. Shock load is the result of an abrupt clutch engagement when the crankshaft and input shaft speeds are not precisely matched. The Flow Control Valve is designed to reduce the risk of traction loss when downshifting or damaging driveline components (broken axles, transmission, etc).