John Deere Auger Gearbox Assy. With Impeller-from JD726John Deere complete auger gearbox assy. 1″ Diameter auger shaft and 1″ diameter impeller shaft. 11 1/2 Diameter impeller. The item “John Deere Auger Gearbox Assy. With Impeller-from JD726″ is in sale since Thursday, January 7, 2016. This item is in the category “Home & Garden\Yard, Garden.