volvo penta 275, I noticed gear oil coming out of the driveshaft bellows while in the water. Pulled boat out and found 2 inch tear on top of the driveshaft bellows. I replaced the bellows but before I put it back in why would there be oil spitting out, I can see why the water was entering, but oil? what seal is leaking? I did blow into the dipstick fill tube and heard air coming out behind the driveshaft going into the unit? What needs replaced? or is this normal?