[RC-Monster Mike]

A slight notchy feel is good for a new diff - after a run or so, they should break in perfectly. Shims may or may not be required, but usually no shims are needed. The spring clip retains the inner bearing. The retaining ring and the other small washer that is placed between the bearings allow both bearings to share the thrust load - much more durable and with the smaller bearings used, we felt it was necessary to retain or slightly improve the overall durability of the 1/8 diffs. :)