My Account
Shopping Cart

Sierra 18-1161 Tapered Roller Bearing for MerCruiser and OMC

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

18-1161
09/12/2036 6:27 AM
Sale Price

$41.23

In Stock (5)

delivery box

Usually delivered within 2 days

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 18-1161 is a high-quality tapered roller bearing designed to meet or exceed OEM specifications for marine stern drive applications. This precision-engineered bearing is manufactured to provide reliable performance in demanding marine environments.

Key Features:

  • Timken bearing #89449 with cone #89410 for superior quality and durability
  • Direct replacement for MerCruiser #31-35990A1 and OMC #983891
  • Located on pinion shaft, driveshaft housing lower bearing position
  • Compatible with MerCruiser IA/IB/IC, EZ Shift, MC-I, R, MR, Alpha One and Gen II drives (except 1.32 ratio)
  • Also fits Vazer stern drives and Johnson/Evinrude outboards
  • Cross-references GLM 21540 and Mallory 9-75122

Sierra marine parts are manufactured to meet stringent OEM requirements, ensuring proper fit and long-lasting performance in your stern drive or outboard motor assembly.

So far so good

My only complaint is that the site couldn't identify the size wheel center caps I needed by vehicle type. I had to measure the center hole on my wheels, lucky I'm a tool junky.

Very easy, and I like the Amazon payment option.

Very easy to order.

thank you, quick easy. Great prices!

One of the top 10 places online to find the best deals on performance parts, either for street or strip. In the last two weeks I found more better deals at Autoplicity then at any other online performance parts store.. Gone_10_in_Sec..

Fantastic place to buy from. They had the best price for K&N oil filters for my motorbikes which was good enough. Then I ordered on a Saturday via normal shipping...got it Tuesday morning! Definitely going to order more in the future.

I could not believe the prices they were offering. I ordered my items and saved a lot on shipping and items arrived the next day!

THANKS

Cheapest price i could find! Great communication, and fast shipping!

good

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