The Dowel Pin in my 18 year old Kitchen Aid Pro6 mixer had crumbled.
1) Removed all of the original grease that was well past its usage date.
2) Borrowed snap ring plier from father-in-law (haven't needed one of these until this fix job)
3) Removed and inspected all of the gears (took plenty of pictures along the way)
4) Established the cause of the issue as being the dowel pin.
5) Ordered replacement parts (went ahead with worm follower gear as well since the original was showing some signs of wear)
6) Re-applied plenty of grease to all gears (make sure to use FOOD GRADE grease)
7) Put the mixer back together (good thing for the pictures since it had been a week)
8) Gave it a whirl, and it is a happy mixer once again
Overall this was an fairly easy fix, with the biggest pain being the grease removal.