KitchenAid blender repair kits are available on Amazon and eBay, as of 2015. The blender repair kit includes two blender couplings and a blender gasket. Select blender parts are also available for purchase at eReplacementParts.com and PartSelect.
Replacing the plastic coupling on a KitchenAid blender involves unscrewing the old coupling and screwing on the new one. A problem arises when attempting to unscrew the old coupling because it turns the entire motor. Options to deal with this problem include prying the coupling off with a screwdriver, or putting an object through the bottom slats of the blender base to stop both the fan blades and the motor blades from turning.