My Account
Shopping Cart

Sierra 18-21005 Greasable Gimbal Bearing for MerCruiser Stern Drives

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

118-21005
06/02/2036 9:55 PM
Sale Price

$86.72

4 left at this price

delivery box

Usually delivered within 2 days

free shipping

FREE SHIPPING

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 18-21005 is a high-quality greasable gimbal bearing designed for MerCruiser stern drive applications. This genuine Sierra replacement bearing provides critical support for the stern drive assembly, ensuring smooth operation and protecting the universal joint and other propulsion system components.

Key Features:

  • Greasable design with pre-drilled grease port for easy maintenance
  • Requires zerk fitting on exterior of gimbal housing for greasing
  • Manufactured with premium components to meet or exceed OEM specifications
  • Made in USA with Sierra's quality standards
  • Direct replacement for multiple MerCruiser part numbers

Applications:

  • MerCruiser Alpha One Gen II (1998 and up)
  • All MerCruiser Bravo models (Bravo One, Two, Three, X, XR, XZ)

Replaces OEM Part Numbers: MerCruiser 30-862540A3, 30-879194A01, 30-862540T1, 30-862540A04, Mallory 9-72412

This bearing supports the stern drive and ensures proper alignment and smooth rotation of the drive assembly. Regular greasing through the external zerk fitting helps maintain optimal performance and extends bearing life. Special installation tools are required for proper installation and removal.

Thank for the prompt service.

Simple and easy.

The product was the cheapest at your site. I was happy the product shipped quickly and arrived exactly when I needed it. I'm very satisfied with your company!!!

Very user-friendly site. Great price.

The price on the battery was the best I had found and the battery shipped out the very next day after I ordered it. When the package arrived the box was beat up pretty bad, I believe the packing may be need to be strengthen some because you never know how the shipper is going to care for the package.

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