So I think I lost my lower unit today. After running all day on the way back in I started hearing a loud clapping noise so I throttled down and heard what sounded like rocks rolling around in the engine. Figured it must have been something in the power head because I didn’t run into anything. After getting the boat out of the water and removing the top fill plug there where heavy metal shavings on the magnet. So my question is can the gears be replaced? If not what is a new LU unit gonna run me in terms of dollar amount? Thanks for any help/advice given.