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Sierra 18-3417 Water Pump Base for MerCruiser MC-I & R Sterndrive

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

18-3417
09/12/2036 8:13 AM
Sale Price

$31.41

3 left at this price

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Usually delivered within 2 days

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Product Details

The Sierra 18-3417 is a replacement water pump lower base designed for MerCruiser MC-I and R sterndrive units without a flush screw in the housing, covering drive serial numbers 2763442 through 6854392 (1970–1984). It is a direct OEM-equivalent replacement for Mercury Marine part number 46-57234A1, engineered to meet or exceed the original equipment specifications it replaces.

Key Features:

  • Direct replacement water pump lower base (base only — upper housing sold separately)
  • Supplied with driveshaft seals included
  • No gaskets included — order separately as needed
  • Meets or exceeds OEM quality standards
  • Designed for MerCruiser MC-I & R drives without flush screw in housing

OEM & Cross-Reference Part Numbers:

  • Mercury Marine: 46-57234A1
  • GLM: 12310
  • Mallory: 9-43306
  • Pro Marine: 65600
  • Redline: RL3417

Note: Models that have been retrofitted with an Alpha-style drive (no preload pin on top of driveshaft) must use Sierra part number 18-3420 instead. This base is also a component included in the Sierra 18-3317 complete water pump kit for pre-Alpha MerCruiser drives.

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