An unload auger assembly for a combine harvester includes a drive coupler configured between adjacent first and second auger segments. The coupler includes a driver component and associated driver cog coupled to the first auger segment. A driven component and associated driven cog is coupled to the second auger segment. The driven cog is rotationally engaged by the driver cog to transmit rotational drive from the first auger segment to the second auger segment. A friction clutch is configured in-line between the driver component and driven component and rotationally couples the driver component to the driven up to a release torque value wherein the friction clutch disengages the driver component from the driven component.