I would like to replace my drain plug housing because there is a small crack in it I believe from the previous owner tightening the plug too much. I definitely don't want to screw this up, so please let me know if I need to do anything else. This is what I plan to do:

-Remove old drain
-Calk old holes (with marine grade calk)
-Drill new holes
-Calk surface around back of new drain
-Screw new drain in

Sounds fine. I re-used the old holes and had no problems.

When I did mine I also encapsulated the inside of the hole in the transon using 2 part underwater epoxy. I did that to seal water from getting behind the housing and working into my transom. I also used epoxy on the screw threads.

BT

When replacing a garboard plug drill the new screw holes in the flange up to the next size of screw. This will assure that it has fresh material to grab into and prevent it from getting sloppy. Life Caulk brand is readily available and would be a good sealant.
Tim T.

Thank you all very much. As I said, I don't want to screw this up.