How to Replace the Seals in an Evinrude Lower Unit

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While lower unit disassembly calls for removing the propeller shaft and bearing carrier as a unit, lower unit disassembly is only recommended for those with significant experience and the precision measuring tools necessary to re-shim those parts. You can, however, replace the two lower unit seals in your Evinrude's lower unit while it is still attached to the rest of the motor by sliding the bearing carrier off the propeller shaft, leaving the propeller shaft in the lower unit.

Items you will need

  • Pliers

  • 1-1/16-inch box-end wrench

  • Steering-wheel puller

  • Internal-large-jawed puller

  • Propeller shaft seals

  • Bearing driver

  • Mallet

  • White marine grease

  • Bearing carrier O-ring

  • Shop towel

  • Gasket sealing compound

  • Soft-faced mallet

  • Torque wrench

Pull the cotter pin from the propeller nut with a pair of pliers. Use a 1-1/16-inch box-end wrench to remove the propeller nut and slide the propeller and any washers or bearings from the propeller shaft. Trigger your trim and tilt control to tilt your motor all the way up.

Set the center pin of the steering wheel puller in the center of the propeller shaft and lock the arms of the puller around the back end of the bearing carrier. Turn the T-handle on the puller to remove the bearing carrier from the gear case.

Remove and discard the O-ring from the bearing carrier. Remove the seals from the propeller side of the bearing carrier with an internal-large-jawed puller.

Set two new propeller shaft seals into the bearing carrier without lubrication. Tap the seals into the housing with a bearing driver and mallet -- the lips of the seal should face the propeller. Apply white marine grease to the lips of the new seal.

Apply white marine grease to a new bearing carrier O-ring and seat the O-ring in the carrier groove. Wipe the carrier surface on both sides of the groove clean with a shop towel.

Apply a thin coat of gasket sealing compound to the bearing carrier support flange, the O-ring flange, the carrier and the threads of the bearing carrier retaining bolts. Align the carrier with the propeller shaft and tap it into place with a soft-faced mallet. Thread the the carrier retaining bolts into place and torque to 12 ft.-lbs.

Warnings

  • Always use a 5/16-inch open-end wrench when removing the nut from the negative post of a marine battery. The positive post uses a 3/16-inch nut. If the lettering or cable color is obscured by dirt or oil, the 5/16-inch wrench won't fit on the positive post.

Tips

  • When you're working on your motor, disconnect the battery cable from the negative post of the battery by removing the nut from the battery post and lifting the cable from the post. Removing the negative battery cable isolates the electrical circuit from the boat's common ground, making it "electrically safe" to work on the boat's electrical or mechanical systems.
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