Just an info update to Itzbinnice and others-
I have finally pulled both augers off and the gearcase apart on my "free" 1988 Ariens ST824. Used the 2x4 method, heat, PB Blaster, and gear puller to free the augers.
Upon inspecting the gearcase, I found that both the 5/16" groove pin that holds the bronze gear onto the auger shaft AND the 3/16" groove pin that holds a collar onto the worm shaft had sheared. There is no noticeable damage to the gears or shaft.
I am amazed that these pins sheared, and more amazed at no apparent damage. I guess these are the second line of defense when the auger shear pins can't do their job (due to rust).
I will be re-assembling this week.
Thanks to all for their help and suggestions.
Ralph