The exploded view of the Auburn LSD shows the gear/cone (A) that fits into the cone seat (B). The spring pack (C) applies a certain amount of preload to the cone clutches. The case is nodular (ductile) iron, and the cones are of a proprietary powdered metal construction. The metallurgical relationship between these two parts is very important so that they don't gall. If you ever have to pull the Auburn apart after it's been used, the cones need to stay with the bores that they are seated to.