During the supercharger pulley upgrade for the 2009 CTS-V we include the Lingenfelter solid isolator coupling to replace the factory spring loaded isolator coupling. The factory spring loaded coupling design can sometime cause a rattle at idle or partial throttle plus we have seen some signs of wear on the shaft from the stock spring loaded isolators. This solid isolator coupling is made from a very durable high temperature plastic and is a direct replacement to the original isolator. Here is a link to the store for purchase --> L960130709
This will work on stock superchargers or the upgraded version with the Lingenfelter pulley and air intake kit.
Here is the Lingenfelter version on the left and the stock on the right.
Picture of the stock one installed on disassembly
New solid isolator going in to housing
Drill and pin the new supercharger pulley .001" press fit on the pin.