changed oil awhile back looked good and clean not milky, motor sat for another 3 months started ran in gear and sat another 2 months, today i noticed that the lower skeg from prop down has lightly coated oil on it and a oil drop was hanging on at the bottom, <br /><br />is this normal ? . <br />is there a was to test the lower unit seals ?<br />is it hard to change seals out ?