Slinger ring ?
Last piece to go on is this large spring ring. It fits in an inner groove in the bowl gear, and fills the gap between spider hub & bowl gear.
Don't know what it's design purpose is for sure, but suspect lubrication control.
In earlier Warn & Saturn catalogs, they called this a "retaining ring", but it serves no mechanical retaining function at all. The spider hub & bowl gear are held together by the previously installed "spacer washer" retainer, and work just fine w/out this ring. Nothing "falls apart" if this "retainer" is removed.
But, in later Saturn catalogs, they call it a "ring, oil slinger" ! Since lubricating oil enters the planetary gears through the hollow mainshaft, and travels outward through the spider gears to the bowl, I think it's intended to "retain" as much oil w/in the planetary cavity as possible.