A clutch controller provides protective disengagement of a clutch between an engine and driven machinery to prevent engine failure due to rapid onset overload. Sensor signals of measured parameters are used by the controller to determine potential engine failure. Multiple, successive sensor signals and elapsed times are assessed during which the current sensor signal value and the scaled rate of change in signal values is compared against a predefined amount. The clutch controller sends a clutch disengagement signal if a calculation result is indicative of imminent failure.