Lower Unit Help

[Matt G]

I'm in the process of changing my lower unit oil. There was an abundance of metal shavings on the plug magnet, but only one metal chunk. It has probably been 2 years since the oil has been changed. Should this one piece concern me? Also, if the oil wasn't milky, is that a sign that all of my seals are in good shape? Also would Academy or West Marine have new plug gaskets?

The oil:
Oil.jpg

The magnet on the plug with all of the shavings:
Drain Plug.jpg

The metal chunk next to the magnet for comparison:
Metal Shard.jpg