1985 merc ob 75hp 4 cyl lower unit question

[mike4]

hello... i have a 1985, 75hp merc ob motor. i just noticed it has a small crack in the lower unit, just above where the propellor is. it is about 2 inches long. it pumps wtr fine... what do i need to do to repair or check out to see what i need to do?

thanks
mike