My Account
Shopping Cart

Sierra 18-3118 Water Pump Housing for Mercury/Mariner Outboards

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-3118
08/04/2036 9:14 PM
Sale Price

$22.34

In Stock (10)

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 18-3118 is a high-quality aftermarket water pump housing designed as a direct replacement for Mercury and Mariner outboard motors. This upper water pump housing is a critical cooling system component that houses the impeller and directs water flow through your engine's cooling system.

Key Features:

  • Precision-engineered to meet or exceed OEM specifications
  • Constructed from durable materials for long-lasting performance
  • Direct replacement for Mercury Marine OEM part number 46-77822A1
  • Compatible with 40-70 HP 2-stroke Mercury and Mariner outboards (1977-1997)
  • Also fits select 20 HP models

OEM Cross-References:

  • Mercury Marine: 46-77822A1, 46-48746A1, 46-48746A3
  • GLM: 12420
  • Mallory: 9-43202
  • AP Part: 1109

This housing is designed for use with various Sierra water pump kits including 18-3507, 18-3322, 18-3323, and 18-3324. Sierra Marine is known for manufacturing premium aftermarket marine engine parts that provide reliable performance and excellent value. Each Sierra product is backed by their comprehensive warranty covering both parts and labor.

everything was easy and fast

Easy to product and checkout.

Quick and easy. Informative on the product to be able to compare other items to make best decision

ordering was simple, paying was very quick and easy with amazon.

seemed a bit hard to find products, but the prices were great and delivery prompt

Quick and Easy

Incredible prices! I purchased a name brand leveling kit for 40% less than any one else is selling them for. Item shipped out within 2 days. Shipping cost is reasonable, and if you leave a review here after your purchase, they'll credit you back $5! BEST DEAL GOING!

great price for turbo timer. received it in a couple of days. great

so far so good

Shopping was quick and fast now just waiting on order Got order and can't wait to install

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