I just had a bad stroke of luck!
I just used the K'Aid grinder attachment for the first time on Friday evening, and it killed the mixer - my new beautiful white K5SSWH model!!
I was grinding some raw beef stew meat to make Sloppy Joes. In the middle of doing it, the mixer began to labor seriously. I immediately turned it off. But the damage was already done! Luckily, my smaller K45SS was there to help finish the job. But that one could have seized also!
I later tried the machine with nothing attached to it and it seemed to pick up speed, but it again began to labor.
I just got off the phone with the appliance repairman at the place where I'm to send the machine for repairs. He told me that using the grinder attachment, especially for meat, causes fluids to back up into the power drive hub and could seize that part and the tansmission, so now, I have to send the machine to him and he'll fix it for me.
The motor is still good. It just can't work well now with the tranny being seized like it is. I'm also going to send the grinder attachment back to Cooking.com after I call them later in the week!
So please, be aware of this the next time that you want to use your K'Aid grinder attachment with your mixer! I'm just going to use the food processor the next time I want to grind any meat!