Your Kitchenaid stand mixer is a great tool, but it’s got mechanical parts that will wear out from time to time. I’ve heard some opinions that the build quality isn’t as good on the newer models, but even the older ones will need some maintenance from time to time. Mine is about 20 years old, and knowing your way around the inside of the machine will help you deal with most common problems yourself, which naturally I can’t recommend that you do. Fundamentally, it’s not a very complicated machine — once you get inside, there’s a small board with a switch that controls the motor which turns some gears which spins and rotates the shaft, and that’s about it.
The two most frequent issues I see people running into are grease running out of the shaft and the worm gear needing to be replaced. Both of these are relatively easy to deal with yourself, but you’ll need some supplies to do a proper job.
There are a lot of videos on YouTube — search for your model and specific problem.
I like ereplacementparts.com a lot. They have instructional videos and sell most replacement parts you’ll need.
In addition to a regular philips head screwdriver, you may need a pair of ring pliers. Not all models have tension retaining rings, but mine did, and if you run into this, there’s no good substitute for this tool.
You will need food-safe planetary grease for repacking the gear box when you’re done. The can is a little pricey, but one repair only uses a small amount and this will last a long time. (If that’s out of stock, the item number is W11200218. Here’s an alternate vendor to try.)
If at some point you want to do a full degrease, you will need a food-safe degreaser. I went with a pure D-limonene solvent. Again, a little goes a long way.
That’s about it. A full gear box disassembly, cleaning, and repacking took me about 90 minutes the first time, including getting comfortable with where everything is. When I did that repair, it was making a grinding noise and I thought the worm gear might be stripped, but that was fine and the problem turned out to be a $6 retaining pin sheared through. Much cheaper than sending it in for service! I’ve since had to open it up a few more times to do more minor maintenance, and I’ve been more confident — these have only taken 10–20 minutes each.
A little about me: I cook a lot, mostly dinner at home for my family and friends but sometimes for massive parties of upwards of 200 people. I’ve been doing sous vide cooking since 2010. I run a food blog called Unselling Convenience (also @unsellingconvenience on Instagram if you’d rather follow along there), which is mostly an inspiration board and memory database of things I’ve enjoyed cooking and probably want to cook again. I believe that shortcuts are great, but not at the expense of quality. I administer the Everyday Sous Vide and Instant Pot Love groups on Facebook. If you buy something from one of the links, I probably get a small commission which won’t even come close to defraying the amount of money I’ve spent on these things over the years but which will make me happy anyway.