Sometime last year I happened upon this Kitchenaid A9 coffee grinder on Ebay. The starting bid was low and there was no reserve so I bid. Much to my surprise I was the only bidder and won the little grinder for a very reasonable price. This is an original A9 from the days when Kitchenaid was owned by Hobart. This design was originally introduced in 1937 and I think it was discontinued in the 1950's. Later in the early 2000s Whirlpool, the current owners of the Kitchenaid brand, reissued an updated version of the little A9.
Once I received it in the mail I gave it a cursory inspection and tested it's operation. Yes, it worked and would grind coffee, but the motor seemed to labor and the grinds were inconsistent. There was also a distinct electrical odor from the motor. A quick tear down revealed worn motor brushes and very worn burrs. I guess the original owner used the grinder a lot. Measuring the brushes with a micrometer, I determined a suitable replacement brush was part number 414 from carbonbrush.com. A light polish to the commutator ring with some 400 grit paper and a drop of light oil on the bearings had the motor working perfectly.
Finding replacement burrs would prove to be more of a challenge. I had read on some coffee forums that the burrs from the newer A9 from Whirlpool were a direct fit. I found the manual for the new version online and called the number in the manual to order new burrs from Whirlpool. The nice gentleman informed me that the replacement burrs were no longer available, but he would be glad to sell me some wonderful new coffee grinding and brewing gadgets. I thanked him for his time and moved on to continue my search for the burrs. Another coffee forum indicated that the burrs were only available as an assembly. I searched for the upper and lower burr support assemblies and found them both available, but the upper support assembly was prohibitively expensive. Fortunately the burrs are removable from their support assemblies and both burrs are identical. I ordered two lower burr support assemblies (pn 9707092) from ddapplianceparts.com. They were very helpful and answered all my questions. Once I placed the order I received the parts in just four days. I highly recommend them.
Below are some photos of the original burrs in the upper and lower support assemblies.
Here are the two new lower support assemblies with new burrs in the upper part of the photo.
And here are the new burrs installed in my original A9 upper and lower burr support assemblies.
So now the little grinder is working perfectly. The motor purrs smoothly with no disconcerting odors and the new burrs produce a very consistent grind for my morning cup. I think I'll have another cup now.