This rubber coupling transmits torque from the gearbox output to the header drive input on a self-propelled forage harvester. It sits between the two flanges, absorbing torsional vibration and accommodating minor misalignment between the shafts. A cracked or worn coupling produces driveline chatter and can lead to spline or bearing damage on the connected shafts. The coupling is molded to match the original flange pattern so that the bolt holes align without reaming. On installation, ensure the flanges are clean and the bolts are torqued to the specified value.