Sierra Oil Seal 18-2059, Replaces OMC 321466, for Evinrude Outboard Prop and Driveshaft

The Sierra 18-2059 Oil Seal is a precision-machined replacement seal built for Evinrude outboard prop and driveshaft applications. It is a direct cross-reference for OMC part number 321466, giving boat owners a reliable way to replace a worn or leaking factory seal without hunting down an original OMC part. The seal's small, compact profile (0.39 x 0.39 x 0.39 inches) is typical of the precision-fit seals used around driveshaft and propeller shaft housings, where even a minor leak can lead to water intrusion or lubricant loss. At just 0.05 pounds, it is a lightweight component designed to be installed as part of routine lower-unit or driveshaft seal maintenance.

Sierra manufactures this seal with a machined exterior finish to help ensure a consistent, snug fit against the housing bore it seats in, which is important for maintaining a proper seal under the pressure and vibration of outboard operation. The part is cataloged under Sierra's Evinrude Outboard Prop & Driveshaft Seals line, making it a straightforward choice for owners servicing this specific area of an Evinrude outboard. Because it is sold as an individual seal rather than a full kit, it allows for targeted replacement of just the failed component.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2059
• UPC: 030999310101
• Category: Evinrude Outboard Prop & Driveshaft Seals
• OEM Cross Reference: 321466
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.05 pounds
• Country of Origin: Taiwan
• Finish: Machined

Fitment

Designed for Evinrude outboard prop and driveshaft seal applications.

Replaces (OEM)

• 321466

Frequently Asked Questions

What does the Sierra 18-2059 oil seal replace? The Sierra 18-2059 is a direct cross-reference for OMC part number 321466, so it can be used wherever that original seal is called for.

Is this seal made by Sierra or a third party? Yes, the 18-2059 is manufactured under the Sierra brand as a replacement oil seal, not a generic unbranded part.

What are the dimensions of the 18-2059 oil seal? It measures 0.39 x 0.39 x 0.39 inches, a small, compact seal sized for driveshaft and propeller shaft housings.

How much does the Sierra 18-2059 oil seal weigh? This seal weighs 0.05 pounds.

What type of outboard is the 18-2059 seal used on? The Sierra 18-2059 is cataloged for Evinrude outboard prop and driveshaft seal applications.

What is the exterior finish of this seal? The 18-2059 has a machined exterior finish, which helps it seat snugly in its housing bore.

Where is the Sierra 18-2059 oil seal manufactured? The country of origin listed for the 18-2059 oil seal is Taiwan.

Will the 18-2059 seal fit if my parts diagram calls out OMC 321466? Yes, since Sierra 18-2059 is cross-referenced to OMC 321466, it is intended as the equivalent replacement for that OEM number.

Does the 18-2059 come as a single seal or a kit? The 18-2059 is sold as an individual oil seal, allowing targeted replacement of just this component rather than a full seal kit.

What is the UPC for the Sierra 18-2059 oil seal? The UPC for this Sierra oil seal is 030999310101.