KA Stand Mixer Question
I have a KitchenAid Pro 600 stand mixer. It's eight years old, has never had a problem and has never been serviced. I use it about once a month, on average, to mix and knead bread dough with a spiral bread hook. Recently I noticed that it makes a "clacking" sound when kneading. The beater shaft (to which the bread hook attaches) has a retaining clip that sits about a quarter of an inch below the bottom of the main unit. When kneading, the beater shaft/retaining clip bounces up against the bottom of the main unit, which is making the "clacking" sound. The dough hook has normal clearance and is not striking the mixing bowl.
Is this sound normal? I don't recall the unit making this noise in the past (but I could be wrong). If the sound isn't normal, is the problem something I might be able to fix myself? Also, I don't know if it's relevant, but there's a thin coating of grease on the part of the beater shaft between the retaining clip and the bottom of the main unit. The grease doesn't appear to leak into the mixing bowl. This clacking sound does not appear to affect the operation of the mixer. Since I noticed it, I've made several batches of bread dough with everything working as expected. Thanks in advance for any advice.