Sierra Oil Seal 18-2032, Replaces OMC 321788, Evinrude Outboard Prop and Driveshaft Seal

The Sierra 18-2032 is an oil seal built for Evinrude outboard prop and driveshaft applications. It seals the shaft bore against water intrusion and lubricant loss, protecting the gear case and driveshaft components from corrosion and premature wear. The seal has a machined exterior finish and is sized to a 1.000 inch outer diameter, a 0.500 inch shaft size, and a 0.188 inch width, making it a precise fit for the driveshaft bore it is designed to seal.

This is a small, low-cost wear part that is commonly replaced during gear case service, driveshaft seal replacement, or lower unit rebuilds. It is sold as a direct-fit replacement carrying the Sierra part number 18-2032 and cross-references to OMC part number 321788, so it can be ordered using either number.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2032
• Product Name: Oil Seal
• Outer Diameter: 1.000 inches
• Shaft Size: 0.500 inches
• Width: 0.188 inches
• Weight: 0.03 pounds
• Exterior Finish: Machined
• UPC: 030999309785
• OEM Cross-Reference: OMC 321788

Fitment

• Evinrude outboard prop and driveshaft applications

Replaces (OEM)

• 321788

Frequently Asked Questions

What does the Sierra 18-2032 oil seal fit? The 18-2032 is designed for Evinrude outboard prop and driveshaft applications, sealing the driveshaft bore in the gear case.

Is the 18-2032 a genuine Sierra part or aftermarket? It is a Sierra-branded oil seal, part number 18-2032, sold as a direct cross-reference replacement rather than an OMC-branded original.

What OEM number does this seal replace? This seal cross-references to OMC part number 321788, so either number can be used to order the correct part.

What are the dimensions of the 18-2032 oil seal? The seal measures 1.000 inch outer diameter, 0.500 inch shaft size, and 0.188 inch width.

How much does the 18-2032 oil seal weigh? It weighs 0.03 pounds, consistent with a small single-component seal.

What finish does the Sierra 18-2032 have? The seal has a machined exterior finish.

Can I use the 18-2032 as a direct replacement without modification? Yes, the 18-2032 is a direct-fit replacement for the Evinrude driveshaft bore it is designed for, using the OMC 321788 cross-reference.

What is the UPC for the Sierra 18-2032 oil seal? The UPC for the Sierra 18-2032 oil seal is 030999309785.

Does the 18-2032 come as a single seal or a kit? It is sold as a single oil seal, part number 18-2032, quantity one per application.

Where is the 18-2032 oil seal typically installed? It is installed in the driveshaft bore of the gear case on applicable Evinrude outboard prop and driveshaft assemblies.