Abstract: A mixer drive unit includes a motor provided with a housing, and a sleeve-like shroud projects outwardly to be positionable in abutting engagement with a top wall of a tank in surrounding relationship to the projecting end of a mixing shaft. The drive unit has a quick-connect drive coupling disposed within the shroud. The coupling includes a drive plate which has a pair of driving flanges projecting downwardly in cantilevered relationship, which driving flanges are spaced radially outwardly from and on substantially diametrically opposite sides of a driving axis. The driving flanges are positionable substantially on diametrically opposite sides of the mixing shaft when the latter is inserted into a pilot opening in the drive plate. The driving flanges define thereon, in the rotational direction, leading drive faces which abut projecting ends of a drive pin secured to the end of the mixing shaft.