HI, I have a mercruiser 4.3 Alpha 1 gen 2 with lower out drive noise Knocking and clunking at idiling. Just bought boat and was not very well taken care of. Just replaced grease in lower unit and it was black, also replaced gimble bearing and bellows. The knocking only is there when in forward or reverse only and does not make any noise when the prop is off. It also does not make any noise if I put my spare aluminum prop on instead of my stainless steel prop. Not sure if I have a bearing going or what. I checked the prop shaft for movement and it moves about 6 thousands up and down. Any help would be greatly appreciated. Thanks
