My Account
Shopping Cart

Sierra 18-2679 Lower Unit Seal Kit for Johnson Evinrude Outboard Motors

Manufacturer

Sierra

<h3>Sierra: Six Decades of Marine Aftermarket Excellence</h3><p><strong>Sierra</strong> has spent nearly 60 years earning its reputation as one of the most trusted names in the marine aftermarket industry. Originally focused on engine and drive components for boats, the brand has grown into a comprehensive source for nearly everything a boater needs to keep their vessel running at its best — from precision instrumentation to complete engine rebuild hardware.</p><p>Now operating as a brand of Dometic, Sierra manages global aftermarket distribution from a 300,000 sq. ft. facility in Litchfield, Illinois. The Sierra brand today encompasses not only its flagship marine parts line but also well-established marine names like Shields and Moeller, offering boaters a broader catalog than ever before. Whether you own an outboard, inboard, or sterndrive, Sierra's engineering team designs products to meet or exceed OEM specifications.</p><h3>Precision Instrumentation You Can Trust on the Water</h3><p>One of Sierra's most recognized product areas is its marine instrumentation lineup. The brand's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> cover everything from classic analog instrument clusters to advanced digital multi-function displays. Sierra offers packages suited to outboards, sterndrives, and gasoline-powered inboards, with options ranging from coordinated analog kits in styles like Arctic, Eclipse, and Amega to modern touchscreen solutions like the R3 multi-function gauge. Features such as scratch-resistant domed glass lenses, silicone-dampened pointers, and perimeter backlighting make these instruments highly readable in all conditions.</p><p>Behind every accurate gauge reading is a properly calibrated sending circuit. Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> are a critical part of that chain, ensuring the signals from sensors and sending units are correctly interpreted by your instruments. These components are built to marine-grade standards to resist moisture, vibration, and corrosion — the realities of life on the water.</p><h3>Engine Internals Built to OEM Standards</h3><p>Sierra's history in marine power is perhaps best demonstrated by its deep catalog of engine components. The brand's <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> cover a wide range of outboard and inboard applications and are engineered to deliver reliable seals in the demanding thermal and chemical environment of a marine engine. For boaters performing seasonal overhauls, top-end rebuilds, or full engine restorations, Sierra gasket kits are a go-to resource trusted by professional marine technicians and DIY boaters alike.</p><h3>A Complete Marine Parts Partner</h3><p>Beyond instrumentation and engine internals, Sierra's catalog spans fuel systems, electrical supplies, steering components, shore power, and more — all covered by what the brand calls an industry-leading warranty. Sierra also maintains a comprehensive parts-finder tool that enables cross-referencing with OEM part numbers from major manufacturers including Mercury, Yamaha, Suzuki, Volvo Penta, and others, making it straightforward to find the right replacement part for virtually any application.</p>

Part Number

18-2679
09/11/2036 7:16 AM
Sale Price

$32.14

1 left at this price

delivery box

Usually delivered within 2 days

Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-2679 Lower Unit Seal Kit is a comprehensive aftermarket replacement solution designed for Johnson and Evinrude outboard motors. This kit provides all the necessary seals and gaskets to rebuild and restore the lower unit gear housing, preventing water intrusion and gear oil leaks that can lead to costly damage.

Complete Kit Contains:

  • (1) 18-2022 Oil Seal - replaces OEM #303345
  • (1) 18-2035 Oil Seal - replaces OEM #327031
  • (1) 18-2534 Seal Kit (Spaghetti Seal) - replaces OEM #309044
  • (1) 18-2891 Bearing Housing Gasket - replaces OEM #303339
  • (2) 18-4248 Drain/Fill Plug Washer - replaces OEM #311598
  • (1) 18-7100 O-Ring - replaces OEM #301877
  • (1) 18-7117 O-Ring - replaces OEM #303360
  • (1) 18-7120 O-Ring - replaces OEM #307853

Application:

  • Johnson/Evinrude 5.5 HP (1955-1964) 2-stroke, 2-cylinder
  • Johnson/Evinrude 6 HP (1965-1967) 2-stroke, 2-cylinder
  • Johnson/Evinrude 7.5 HP (1955-1958) 2-stroke, 2-cylinder

This Sierra seal kit is manufactured with marine-grade materials that meet or exceed OEM specifications, providing reliable protection against water contamination and gear oil loss. The kit cross-references to GLM part number 87604. Regular maintenance of lower unit seals helps prevent milky or contaminated gear oil, extends the life of internal gears and bearings, and ensures optimal performance on the water.

This is my first order with you , so I will see how it goes.

Great product at a very reasonable price. Driver could have helped lower package.

Quick and easy

Shipping is too expensive.

Best price and super easy to use.

I placed my order on a Saturday and by Monday my order was shipped. Autoplicity had the best price I could find on the Thule Apex Swing bike carrier. They also had a great site, reasonable shipping and an easy checkout.

This is my first time ordering from them, but it certainly will not be my last. They have all the parts I need and the process and ship fast. Great company. And they're prices are awesome.

Easy and quick

Very nice transaction! Great doing business with you.

Easy shopping experience

Great prices and item shipped quick!

had the best price on the Internet and free shipping!

Cheaper price than the competitors and free shipping. It's pure win.

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy