Sierra 18-2660 Johnson/Evinrude Lower Unit Seal Kit

Revive Your Outboard's Gearcase with Reliable Seals

Nothing disrupts a day on the water like a leaky lower unit on your Johnson or Evinrude outboard. Water intrusion leads to corrosion, gear damage, and costly repairs. That's where a quality seal kit steps in, restoring waterproof integrity and smooth performance. This Sierra kit targets those critical seals prone to wear from constant exposure to harsh marine environments, ensuring your propeller shaft, driveshaft, and shift rod stay protected.

Boaters trust Sierra for affordable, high-performance alternatives that match or exceed original specs. Built with durable materials resistant to oil, fuel, and saltwater, it handles the demands of freshwater lakes or coastal adventures alike.

Key Components for a Complete Rebuild

The kit packs everything needed for a thorough gearcase refresh:

• Propeller shaft seals to prevent oil leaks at the prop.
• Driveshaft seals guarding against water entry from above.
• Shift rod seals for precise operation without contamination.
• Precise O-rings and gaskets for seamless assembly.

Designed specifically for select Johnson and Evinrude models, it fits snugly without modifications, saving you time and frustration during service.

Spot the Signs: When to Replace Your Seals

Milky gear oil? Emulsified lubricant signals water mixing in. Other red flags include:

• Whining gears or unusual vibrations.
• Oil seeping from the prop or boot.
• Overheating lower unit during runs.
• Reduced propulsion efficiency.

Addressing these early prevents propeller shaft bearing failure or worse—complete lower unit replacement. Regular inspections every season catch issues before they escalate.

DIY Installation Tips for Confident Boaters

Many weekend mechanics tackle this job in a garage or driveway. Here's a streamlined approach:

1. Prep: Drain gear oil, remove lower unit from the midsection.
2. Disassemble: Pull prop, shaft, and inspect bearings/gears for collateral damage.
3. Replace: Pry out old seals carefully, tap new ones in evenly with a seal driver.
4. Reassemble: Torque to spec, refill with high-quality gear lube.
5. Test: Run in a barrel or on the water, check for leaks.

Pro tip: Clean mating surfaces meticulously and use marine sealant sparingly on gaskets. Expect 4-8 hours for first-timers; seasoned pros do it quicker.

Long-Term Performance and Maintenance

Post-install, extend seal life with these habits:

• Flush with fresh water after every saltwater trip.
• Change gear oil annually or every 100 hours.
• Inspect props for dings that stress seals.
• Avoid overpropping, which amps up gearcase pressure.

Sierra's robust construction means fewer breakdowns, more reliable outings, and peace of mind on the water.