How to Rebuild the Lower End of an Evinrude

by Will Charpentier

When you need to rebuild the lower end of an Evinrude, the task may seem complicated, but take heart: The work does require a reasonable amount of mechanical skill, and, depending on the model of the motor and the extent to which you must rebuild the lower unit, you may need to borrow two proprietary tools from the dealer; still, the lower unit is nothing more than a mechanical gear case, with a propeller on one end and a driveshaft on the other.

Disassembly

Remove the screws holding the water pump, using a screwdriver. Lift the water pump housing and impeller from the driveshaft. Remove the water pump impeller from the driveshaft.

Remove the bearing carrier retaining screws. Slide the bearing carrier free of the propeller shaft and remove the bearing carrier seal. Pull the driveshaft seal and driveshaft from the unit, as well. Note that on some models, special tools are required for removing these two seals.

Check for damaged propeller shaft seals and replace, if necessary.

Overhaul and Reassembly

Apply a light coating of gasket sealer to the metal casing of a new bearing carrier seal. Install the seal with the lip of the seal facing inward.

Apply a light coating of gasket sealer to the metal casing of a new driveshaft seal. Install the seal with the lip of the seal facing down. Insert the pinion gear and the propeller shaft and gear assembly into the lower unit.

Slide the driveshaft down through the seal and the lower unit. Rotate the driveshaft slightly to allow the splines on the end of the driveshaft to index with the internal splines of the pinion gear.

Apply a light coating of gasket sealer to the threads of the bearing carrier retaining screws. Reinstall the carrier with the flat surface facing upward. Tighten the screws to 84 inch-pounds.

Set the water pump impeller pin into the driveshaft. Apply a light coating of machine oil to the impeller blades and insert the impeller in the pump body. Apply a light coating of gasket sealer to the threads of the water pump retaining screws. Slide the water pump down the driveshaft, thread the retaining screws into place and tighten them to 35 inch-pounds.

Items you will need

  • Screwdriver
  • Gasket sealer
  • Puller bridge (Evinrude proprietary tool)
  • Bearing puller (Evinrude proprietary tool)
  • Bearing carrier seal
  • Driveshaft seal
  • Torque wrench
  • Machine oil

Warning

  • Removing the driveshaft and carrier seals of some Evinrude outboard motors requires the use of two proprietary Evinrude tools, a puller bridge (part number #432127) and bearing puller (part number #432130).

References

  • "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.