SC oil change, once a year (pick your time). Ge all the old out with a syringe or spray bottle tube and refill to the bottom of the threads (should take about 2 bottles or less depending on how much you got out). SC oil is about 6 bucks a bottle at the dealer.
the coupler is what couples the pulley to the rotors inside the SC. Over time it can wear out and a rattle will occur, when this happens simply replace it. The SC oil is very easy and shouldnt take more then 15 minutes.
You may want to consider joining goclubgp at www.goclubgp.com . We have quite a few members in Dayton including Tim King who loves working on our motors.