Abstract: A gravity box grain cart has an auger assembly for conveying granular material. The auger assembly includes an auger with an axis and a helical flight along the axis, with the auger having a feed end, a discharge end and a central auger section therebetween. A cylindrical auger tube surrounds at least the central auger section, and the feed end of the auger extends outwardly from the tube. A sump for granular material is connected to the auger tube and surrounds the feed end of the auger. The auger, auger tube and sump are pivotable about approximately the feed end of the auger in approximately a first plane. The auger, auger tube and sump are further pivotable about approximately the feed end of the auger in a second plane approximately perpendicular to the first plane. The sump has a diameter through the axis of the auger which is about perpendicular to the second plane, and which is at least about 40-100% larger than the diameter of the auger tube.