5KSB52BGR4 KitchenAid Blender

First I inserted a small diameter rod in the motor fins to keep the motor from turning. Then I simply loosened the coupling. (Please know this is a left-hand thread). The coupling was not that tight. New coupling only requires a snug hand -tightening. You are are good to go!

My first step in repairing the broken KitchenAid blender, was to politely inform my wife HOW & WHY the blender broke in the first place. She thanked me for that, so she would know for the future. (whew...)
Replacing the drive tooth wheel was a cinch. We who are reading this are all fortunate to have others, before us, fill us in on t ... Read more he details. I'm glad I read previous testimonials instead of banking on KitchenAid's instructions. Although the motor shaft is a left-hand threaded mount, the mfg's instructions said to remove the defective coupler by prying the wheel off in various positions with a 1/2" screwdriver!! Reading previous repair stories here, proved to be more reliable.
It took more time for me to find a tool to aid in the removal of the old part, than it was to replace the part itself. I needed to find something that was thin enough to fit around the motor shaft and hold it from turning while I unscrewed the defective coupler in a "clockwise" direction. I eventually found a small, old pair of adjustable wire strippers. I was able to wiggle them in and barely grab the motor shaft. I turned the coupling clockwise and it came right off. No problem at all. Turns out that all that was probably needed was to insert a small punch between the motor fan blades through the bottom of the unit just to keep the motor from turning. The new fitting doesn't have to be on any more than hand tight, as the blender runs in a clockwise rotation, and will keep the fitting snug all the time.
Good luck, home mechanics.

replaced jar