Usually things like coffee grinders or electric stand mixers that have a motor and a gearbox include a plastic piece that is intended to fail first precisely so they are easily and cheaply repaired. They honestly should advertise it on the box, but that'd cut into their repair business.
They are designed to break if the machine comes under too much stress that could break more expensive parts of the machine if the "fuse" wasn't included. Instead, that part breaks, making it cheap and easy to replace.
Indeed, if you ever find a Kitchen Aid stand mixer in the trash, it likely got there because a gear in the gearbox is designed for this reason; they are cheap and easy to replace for anyone with a modest amount of mechanical ability, and those mixers aren't inexpensive new.
Yea, if you can get Kitchenaid to sell it to you. They absolutely refuse to sell me, as a consumer, the grease they use to lubricate the gear head. Even after arguing for half an hour with customer service.
Grease isn't something that Kitchenaid makes. You should be able to easily buy appropriate grease anywhere for dirt-cheap. For small appliances with plastic gears, it's most likely some kind of white lithium grease. A little research online should tell you what kind of grease is appropriate for that application, and then it should be easy to get some inexpensively, perhaps even at your local auto parts store in a tiny single-use packet for $1.
They do sell a food-grade grease, but not to me. Looking at the existing grease in the gearhead, it looks similar to axle grease. Researching food-grade grease on Amazon shows many reviews raising this problem, but no definitive solutions. It's not lithium grease.
Why would you need a "food grade" grease? You're not eating the grease; it's supposed to be contained inside the mechanism. If it's leaking out into the food, that sounds like a pretty horrible design and a product you shouldn't use under any circumstances. Maybe I'm just not understanding this product at all.
My mixer is 50 years old. Over the years, I've pulled the head apart a couple of times when it starts to squeak, and it's obvious there is a very gradual loss of grease - I've re-spread it into the gears.
There is no seal on the shaft that holds the beater.
Kitchenaid is made by Hobart, and they are the lead manufacturer in this market. The design is fine and very rugged.
I don't want use any grease that has traces of heavy metals or, e.g., moly disulfide. There is such a thing as food grade grease for use in mixers, candy machines, etc., but I just haven't yet laid my hands on any.
