How to Replace an Oil Seal in an Evinrude Outboard

The most important part of lower unit maintenance is watching for the telltale signs of an oil leak, both during and after you go boating. When you see a sheen of oil on the surface of the water, a drop of oil on your propeller or gear case oil that looks milky, it's time to replace the oil seal in your Evinrude outboard. Water can wreak havoc in the gear case of your lower unit and if oil can leak from your gear case, water can get in.

Remove the two propeller shaft bearing housing -- the bearing carrier -- retaining bolts. Use a small bearing driver to gently tap one of the bearing carrier ears, until it is cocked about 10 degrees from alignment with the gear case, exposing the back of the ears. Use a rubber mallet to tap alternately on the back of each carrier ear, driving the carrier slowly back and out of the gear case. Protect the pinion and driveshaft gears from damage by keeping pressure inward on the propeller shaft while tapping the carrier.

Remove and discard the O-ring from the bearing carrier. Remove the seal saver from the bearing carrier. Temporarily reinstall the bearing carrier back into the gear case, then use a small internal-jawed puller and a slide-hammer to remove the seal from the bearing carrier. Remove the carrier from the housing again.

Clean the bearing carrier O-ring groove of all traces of sealant. Apply a light coating of penetrating oil to the outer surface of the new propeller shaft seal, from the seal kit. Install the seal into the bearing carrier with the letters on the casing facing outward. Use a suitably sized socket or bearing driver and a mallet to gently tap the seal into the bearing carrier.

Apply a light coating of white marine grease to the lips of the new seal and to the new bearing carrier O-ring, also from the seal replacement kit. Install the new bearing carrier O-ring to the carrier groove. Wipe the carrier surface clean on either side of the groove with a clean cloth.

Apply a light coating of gasket sealant to the threads of the bearing carrier screws and to the flange around the O-ring on the bearing carrier housing, as well. Install the carrier over the propeller shaft and into the gear case, seating the carrier to the case while aligning the bolt ears.

Install the bearing carrier retaining bolts and tighten to 62 inch-pounds with a torque driver. Install the seal saver onto the propeller shaft with the lip facing outward and press it securely into position.


  • "Evinrude Repair Manual 2.5 to 250 HP Models, 2002-2007"; Seloc Marine; 2007

About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.