Sierra 18-3289 Double Lip Seal, Replaces 26-864319, for Gen II Upper Housing

The Sierra 18-3289 is a double lip seal designed for the Gen II upper housing on marine sterndrive applications. It serves as a direct replacement seal used during upper housing rebuilds and maintenance, helping keep lubricant contained and water out of the housing where it is installed. The double-lip design provides two sealing edges along the shaft, giving added protection against leakage compared to a single-lip seal.

This seal is a compact, purpose-built component intended for use on Mercury outboard and MerCruiser sterndrive applications that use the Gen II upper housing. It cross-references directly to OEM part number 26-864319, making it straightforward to identify as the correct replacement when servicing this housing. Each unit is sold individually and ships in compact packaging suited to a small precision seal.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3289
• Product Type: Double Lip Seal
• Application: Gen II Upper Housing
• Package Quantity: 1
• Package Dimensions: 5.13 x 4 x 0.25 inches
• Weight: 0.03 pounds
• UPC: 808282185763

Fitment

Fits the Gen II upper housing on applicable Mercury outboard and MerCruiser sterndrive units.

Replaces (OEM)

• 26-864319

Frequently Asked Questions

What does the Sierra 18-3289 seal fit? The Sierra 18-3289 is a double lip seal made for the Gen II upper housing on Mercury outboard and MerCruiser sterndrive units.

What OEM part number does 18-3289 replace? Sierra 18-3289 replaces OEM part number 26-864319.

Is 18-3289 a single or double lip seal? It is a double lip seal, meaning it has two sealing edges along the shaft rather than one, for added protection against leakage.

How many seals come in a package? The Sierra 18-3289 double lip seal is packaged and sold as a single unit.

What are the dimensions of the 18-3289 seal package? The packaged Sierra 18-3289 seal measures 5.13 x 4 x 0.25 inches.

How much does the 18-3289 seal weigh? The Sierra 18-3289 double lip seal weighs 0.03 pounds.

Where is this seal installed on the housing? Sierra 18-3289 is installed in the Gen II upper housing as part of the seal assembly during rebuild or maintenance.

Is Sierra 18-3289 a genuine Sierra part or a generic aftermarket seal? 18-3289 is the Sierra manufacturer part number for this double lip seal; it is not a generic or unbranded part.

Will the 18-3289 seal work on Mercury outboard motors? Yes, the Sierra 18-3289 double lip seal is used on Mercury outboard applications that use the Gen II upper housing.

Does 18-3289 work for MerCruiser sterndrive units as well as outboards? The Sierra 18-3289 Gen II upper housing seal is used on both Mercury outboard and MerCruiser sterndrive applications that share this housing.