When I "hand inspect" my drive bellows it looks and feels fine and there are no leaks however I do get a fair amount of black on my hand from the bellows. Is this just normal oxidation or a sign of impending bellows failure? Yes, it's been several years since the bellows were last changed, but the boat has been in storage. I don't want to pay to have the bellows changed now if not necessary, but I also don't want to pay more later for more parts and also have a boating vacation (in a week) ruined for my family.