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Sierra 18-6243 Zinc Gimbal Housing Anode for MerCruiser Sterndrive 821631Q1

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

18-6243
08/07/2036 12:53 AM
Sale Price

$40.26

In Stock (6)

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Usually delivered within 2 days

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No Hassle Returns

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Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-6243 is a zinc gimbal housing anode designed as a direct replacement for MerCruiser sterndrive applications. This sacrificial anode mounts at the base of the gimbal housing and works by attracting galvanic corrosion away from critical metal components, including shafts, propellers, rudders, and drive components — allowing the anode itself to deteriorate while protecting the surrounding hardware.

Key Features:

  • Zinc construction — ideal for saltwater and brackish water environments
  • Replaces OEM Mercury/MerCruiser part numbers 821631Q1, 821631A1, 821631B1, 97-821631C, 43994A2
  • Mounts at the gimbal housing on MerCruiser R, MR, and Alpha One sterndrive assemblies
  • Fits over the trim line manifold for a secure, OEM-style installation
  • Manufactured to meet or exceed OEM corrosion protection standards
  • Protects shafts, propellers, rudders, and other underwater drive components from galvanic corrosion

Important Note: Zinc anodes are recommended for saltwater and brackish water use. For freshwater applications, a magnesium anode is the preferred material choice.

Sierra marine parts are manufactured to meet or exceed OEM specifications, ensuring reliable, long-lasting corrosion protection for your MerCruiser sterndrive system. Inspect the anode regularly and replace when signs of significant deterioration or pitting are observed.

Thanks

Simple and fast

Great A++

Quick ez process.

if it went any better i could do it in my sleep . it's great doing business with you .

I hope this thing is awesome

It was fast and easy.

Great experience. I would definitely recommend.

Great

Saved me $150 over Mopar brand fan assembly for my 2005 300C 5.7 HEMI. Delivery was extremely quick, the part was a perfect fit, and working as expected. Thank you!!!

Great prices, fast shipping. Would recommend.

Great product and speedy service!

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