I have a oil when my bike is parked on the kick stand. I have taken the primary inner and outer of once before to repair this leak. I replaced all the orings and gaskets. The leak appeared to come from the shifter seal. I have it apart right now and I am going to replace the seal for the shifter and input. but between these 2 seals is a rubber cover about 2 inch around that is punctured. It does not appear to be replaceable. What is it and could that be my oil leak?