A method of engaging a clutch in an agricultural machine

A method of coupling a load to a power source by means of a clutch, the method comprising a pre-fill first step of initially rapidly increasing pressure in an actuator 20 to bring pressure plates 40 into contact with the clutch plates 50. In a second step the pressure is gradually increased during a second time interval so that the pressure and clutch plates 40,50 start to rotate together. During the second step while the pressure is increasing the pressure is decreased at regular short intervals causing pressure dips. By creating the pressure dips while engaging the plates 40,50 an overall maximum torque is reduced. In a final third step after the second time interval the pressure is levelled off maintain the engagement of the pressure plates 40 with the clutch plates 50 to allow the load to be driven by the power source. The load may be a header of a combine/forage harvester and a safety clutch may be placed between the clutch and the header.