KitchenAid A-9 Electric Burr Grinder "acorn nuts" Questions

I am trying to dissasemble my A9 grinder to clean the burr mill. The acorn nut on top doesn't budge. Is it reverse threaded or just tight? Left hand threads.

the parts list. It should take you to a Sears page with the parts you need. The part number for the Acorn Nut is 9707016

...it. Then a tooth brush. When reassembling the burr assembly turn all the way in until you see the acorn nut in the center rotate. STOP. Back the assembly back until the nut stops rotating. That is ...

I need to order the acorn nut for a kitchenaid A-9 burr coffee grinder I found this while searching for shear pins http://www.partselect.com/PS984110-Whirlpool-9707016-Nut-Acorn.htm