Originally Posted by Liguori
Instruction Sheet for KitchenAid Blender Coupling Drive Installation
1) Unplug Blender
2) With blender facing you, insert flat blade screwdriver (3/8 to 7/16 inch) between the black coupling drive and the blender housing.
3) Raise up on the screwdriver to turn the coupling drive clockwise (it is a left hand thread so the coupler keeps tight during use). Keep making ¼ turns until the coupling drive comes off. Do not worry about bending the old coupling drive. You are going to throw it away.
4) There is a flat spot on the blender shaft and construction of a flat tool is possible, but not necessary.
5) Check the threads on the blender shaft and clean the old metal shavings from the threads. Hand tighten the new coupling drive. It will be kept tight during normal use due to the left hand thread design and the clockwise spinning of the blades.
The Flat spot was deceiving to me, it implied a pressed on part so I thought I had a "unique" issue that nobody had seen. The flat spot is now obviously an area for locking the shaft with some special tool (I did not use such a tool). I did EXACTLY as you prescribed a large flat head forcing the metal disk (the remnants of the drive coupling) CLOCKWISE and upward in small increments, maybe 8 times, and voila, cleaned the threads with an xacto knife and I am in business...THANKS!!!