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Sierra 18-217521 Engine Coupler for OMC/Volvo Penta

Manufacturer

Sierra

<h3>Sierra Marine: Over 58 Years of Aftermarket Excellence</h3><p><strong>Sierra</strong> has built a reputation as one of the most trusted names on the water, bringing more than five decades of engineering expertise to the marine aftermarket. <a href="/7570-sierra">Sierra</a> is a globally recognized manufacturer with a rich 58-year history developing aftermarket engine and drive parts primarily for the marine industry — covering everything from inboard sterndrive applications to outboard engines across a huge range of makes and models.</p><p>In 2022, the Sierra brand underwent a significant expansion, broadening its portfolio to serve both the boating sector and select land-based applications. Today, Sierra encompasses its full core product lineup alongside well-established marine brands like Shields and Moeller, giving boaters a single trusted source for a comprehensive range of parts and supplies.</p><h3>Instrumentation Built for the Helm</h3><p>Sierra is perhaps best known for its industry-leading marine instrumentation. The brand offers one of the widest selections of <a href="/7570-sierra-gauges-200483">marine gauges</a> available in the aftermarket, spanning both analog and digital formats. Whether you need a replacement fuel level indicator, oil pressure gauge, water temperature monitor, or voltmeter, Sierra engineers these instruments to deliver accurate, reliable readings in demanding on-water conditions. All gauges are built to be water-resistant, UV-protected, and corrosion-resistant — critical traits in a saltwater or freshwater marine environment.</p><p>For boaters who want a coordinated helm setup, Sierra's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> make it easy to monitor all key performance metrics in a cohesive, matched style. Available in a variety of series — from the classic Lido and Amega styles to more modern configurations — these multi-function sets cover everything from RPM and speed to fuel level and trim angle in a single package.</p><p>One of the most critical instruments on any vessel, the <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauge</a> tells the operator exactly how hard the engine is working. Sierra's tachometer lineup spans a wide RPM range and is designed to interface with outboard, inboard, and sterndrive gas engines. With features like scratch-resistant lenses, perimeter lighting for night visibility, and compatibility with NMEA 2000 systems on select models, Sierra tachometers are a go-to upgrade or OEM replacement for serious boaters.</p><h3>Marine Engine Oils Formulated for the Water</h3><p>Beyond instrumentation, Sierra produces a full line of <a href="/7570-sierra-engine-oil-12138">marine engine oils</a> developed specifically for the rigors of boat engine operation. From 4-stroke FC-W certified oils to full synthetic and semi-synthetic blends in a range of viscosities, Sierra's lubricants are formulated to meet or exceed the requirements of leading marine engine manufacturers. Their engine oils are engineered to reduce friction and sludge buildup, provide maximum corrosion protection, and keep engines running cleanly — whether you're navigating coastal waters or freshwater lakes.</p><h3>Why Boaters Trust Sierra</h3><ul style="list-style:disc"><li>Over 58 years of marine aftermarket manufacturing experience</li><li>Products meet or exceed OEM standards across inboard, outboard, and sterndrive applications</li><li>Industry-leading warranty on instrumentation and parts</li><li>Comprehensive catalog spanning instrumentation, engine parts, fuel systems, and electrical supplies</li><li>Expanded brand portfolio including legacy names Shields and Moeller</li></ul>

Part Number

18-217521
09/13/2036 2:47 AM
Sale Price

$281.07

4 left at this price

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-217521 is a premium replacement engine coupler designed for marine applications. This coupler serves as a critical connection component between the engine and drive system, transferring power while allowing for slight misalignment and absorbing vibration.

Key Features:

  • Direct replacement for OMC/Volvo Penta part number 3858437
  • Engineered to OEM specifications for proper fit and performance
  • Durable construction designed to withstand marine environment conditions
  • Essential component for maintaining smooth power transfer from engine to outdrive

This engine coupler is a wear item that should be inspected regularly and replaced as needed to prevent damage to the engine and drive system. Sierra Marine offers reliable aftermarket parts that meet or exceed original equipment standards.

Thank you, easy!!

Arrived qickly and looks great haven't jnstalled yet but looks pretty straight forward

Great customer service and fast shipping thank you!

Showed inventory..good online service

Great so far

sounds too inexpensive, but hey you only live once...

Ordered these pads from another source &amp; it was cancelled stating unavailable. Autoplicity has the same part, a bit more $ but they have the part I need and that is what counts. Thanks Autoplicity! You have my business!

Overall great experience

Easy fast thanks

It's easy ordering so far

Easy to use

great and good price

Great

It was easy.

so far so good

great product, easy install and more power. installed on a 2012 hemi ram. KNN-631561

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