727 tailshaft housing snap ring

If the snap ring in front of the bearing came loose then the shaft could move rearward; allowing the forward and direct drums and the governor to move rearward; losing pressure. But not the snap ring behind the bearing; and not the ring set into the tailshaft housing. If the snap ring at the front of the tailshaft came off, I don't see what difference it would make because the rearward movement of the tailshaft is limited by the front snap ring on the bearing. Maybe I'll learn something here.