A harvesting machine crop unloading spout assembly includes an unloading tube elbow terminating at a first end in a first flange that is secured to the outlet of a harvesting machine crop tank. The first flange includes one or more bearings permitting it to swivel about a swivel axis and the unloading tube elbow includes a cranked portion terminating at a second end in an opening. The spout assembly further includes a fixed member adjacent the unloading tube elbow, the unloading tube elbow connected to the fixed member by way of a pivot the axis of which coincides with the swivel axis. The spout assembly includes a rotatable drive gear and a motor drivingly engaged therewith for causing rotation of the unloading tube elbow about the swivel axis, the axis of rotation of the drive gear also coinciding with the swivel axis.