Stern drive lower unit maintenance checklist
1. Inspect for lower unit for chips, leakage, anode and propeller.
2. Make sure lower unit is in the down position for at least ½ hours before draining gear lube.
3. Remove bottom drain plug first, the slower draining makes it easy to inspect the used lubricant.
4. Remove the top drain plug.
5. Fill with correct gear lube from the bottom up.
6. Replace top drain plug when lube overfills then replace lower plug quickly.
7. Remove propeller and check for fishing line, wire or other items that will damage the seal around the prop shaft.
8. Repair or replace propeller as needed. If it’s painted, rough the surface with sand paper or abrasive cloth, clean with thinner or acetone to remove grease and repaint propeller before installation.
9. Remove or sand corrosion and scratches on the lower unit. Clean with thinner or acetone and repaint with appropriate paint. Some minor corrosion can be removes with the abrasive cloth and a cola product.
10. Lubricate the tilt hinge and clean the polished struts on the hydraulic tilt unit. Dirt and scratches can damage the seals in the hydraulic cylinders. If you don’t have a high quality metal polish you can always use a little Crest toothpaste.
And don't forget to winterize if you live in the cold weather states.