The invention pertains to a corn head (14) having a frame (18). The corn head (14) includes a plurality of row units (20, 22, 24), a common drive shaft (36), a like plurality of slip clutches (50, 52) each coupling an individual row unit (20, 22, 24) with said drive shaft (36).At least one vibration sensor (58, 60, 62, 64, 66 ) fixed to said frame (18) is proposed for providing signals indicative of sensed vibrations and a processing unit for receiving and processing the vibration sensor signals to indicate slipping of at least one slip clutch (50, 52).
