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Sierra 18-1728 Bellows Flange Ring for MerCruiser Alpha One Gen II

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

118-1728
06/02/2036 10:37 PM
Sale Price

$17.72

2 left at this price

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Usually delivered within 2 days

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Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-1728 is a precision-machined bellows flange ring designed specifically for MerCruiser Alpha One Generation II stern drives manufactured from 1991 to present (serial numbers 0D469859 and up). This critical transom component ensures a secure seal between the bellows and drive unit, protecting internal components from water intrusion and corrosion.

Key Features:

  • Precision-machined to OEM specifications for exact fit and reliable performance
  • Direct replacement for MerCruiser part number 816607 and Mallory 9-73117
  • Engineered to withstand harsh marine environments and high-performance demands
  • Lightweight design at just 0.04 lbs for easy installation
  • Meets or exceeds original equipment specifications

Sierra Marine has over 50 years of experience manufacturing quality marine engine components, supplying OEM manufacturers and boat builders worldwide. This flange ring is an essential component for bellows system maintenance and should be inspected regularly and replaced as needed to prevent costly drive unit damage. Compatible with MerCruiser Alpha One Gen II, Vazer Drive, and Vazer Transom applications.

The item arrived three days after I ordered it very fast shipping thank you

Easy process

Easy to navigate so far.

Decent

The part I needed was in stock at a fair price and delivery was free. Item delivered in perfect condition in a few days.

Found product at a lower price than a couple of other sites convenient fast shipping with quality of followup of product ordered thanks

Shipping was extremely fast a on a hard to find Item, The price with free shipping was better than buying elsewhere with paid shipping I am very satisfied

Items arrived quickly - don't remember receiving any shipping notification though beforehand

Ordering process was overall pretty simple. Shipping cost was alittle bit higher than expected.

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