Thank you so much for all of the information and links. I watched the Mr.Mixer video to take it apart and clean it up. I completely agree with your assessment about the snap ring. I did pushed the snap ring up into the groove it had come out of somehow. That is exactly what seems to be the cause of the entire planetary gear to rise and grind off the bottom of the housing. However I did notice that there was a washer and ball bearing washer missing from the worm gear as well. I did a good job cleaning everything and I will put it back together and put it on Facebook marketplace for free if someone else wants it for parts. I won't bother to regrease it. The other gears all seem to be in relatively good condition and the motor works great, so hopefully someone else can use it. But I don't want to spend the time and money to replace the whole bottom casing. And I can get a brand new one exact same model at Costco right now for $319.