I have the 12 bolt for my car apart at the momment and I am trying to figure out why it is setup the way it is. It has a 3 series carrier (identified by the number on it) and a gear with a spacer. The gear has 41 teeth...the pinion has 11 teeth. The pinion gear has some markings on it, 8620 82-0630-1. Why was the spacer used? Is the pinion smaller for some reason, causing the ring gear to need a spacer?