My 1990 Volvo Penta outdrive has a bellows (looks much like a cv joint boot in a car) I just noticed there is a crack in it.my question is what does the "boot" protect? How serious is the crack,and can I fix it with duct tape?It looks like it would be a job to put a new one on it looks like the outdrive would have to be dropped from the engine to get at the top clamp.Any ideas?Thanks Star.