Sierra Oil Seal 18-2014, Replaces Mercury Marine 26-89238, Fits R/MR and Alpha I Stern Drives

The Sierra Oil Seal 18-2014 is a round, white oil seal engineered as a direct replacement for the oil seal used in specific stern drive applications. It is listed with an oil seal description code of WPB,L and is supplied one per package. This seal is a precision-fit replacement part designed to restore proper sealing where the original equipment seal has worn out, hardened, or begun to leak, helping protect stern drive components from water intrusion and lubricant loss.

Sierra part number 18-2014 is a direct cross-reference for Mercury Marine part number 26-89238, so boat owners and marine technicians can order it as a drop-in equivalent to the original Mercury Marine seal. It is designed for use on R and MR stern drives equipped with Alpha I lower units from serial number 6225577 and up, as well as Alpha I SS stern drives across all serial numbers. Because stern drive seal applications vary by serial number range and drive model, confirming the drive model and serial number before ordering helps ensure the correct seal is installed.

The seal is compact and lightweight, consistent with its role as a small sealing component within the stern drive water pump base assembly area. Its white finish and round shape are as supplied by the manufacturer.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2014
• Product Type: Oil Seal
• Oil Seal Description Code: WPB,L
• Color: White
• Shape: Round
• Weight: 0.03 pounds
• Package Dimensions: 12.9 cm H x 0.4 cm L x 9.8 cm W
• Quantity Per Application: 1
• UPC: 030999309600
• Replaces (OEM): Mercury Marine 26-89238

Fitment

• R and MR stern drives with Alpha I, serial number 6225577 and up
• Alpha I SS stern drives, all serial numbers

Replaces (OEM)

• Mercury Marine 26-89238

Frequently Asked Questions

What does Sierra oil seal 18-2014 replace? Sierra 18-2014 is a direct cross-reference for Mercury Marine part number 26-89238, so it can be ordered as an equivalent replacement for that original seal.

Which stern drives use the 18-2014 oil seal? This seal fits R and MR stern drives equipped with Alpha I from serial number 6225577 and up, as well as Alpha I SS stern drives across all serial numbers.

How many seals come in a package? The Sierra 18-2014 oil seal is supplied one per package, listed at a quantity of 1 per application.

What color is the 18-2014 seal? It is white, and it has a round shape as supplied by Sierra.

How much does the Sierra 18-2014 oil seal weigh? The seal weighs 0.03 pounds.

What are the package dimensions of the 18-2014 oil seal? The package measures 12.9 cm H x 0.4 cm L x 9.8 cm W.

Is my stern drive serial number important when ordering this seal? Yes. Sierra 18-2014 is specified for R/MR stern drives with Alpha I from serial number 6225577 and up, so checking your drive's serial number against that range helps confirm fit; Alpha I SS stern drives are covered at all serial numbers.

Is the 18-2014 an OEM or aftermarket seal? It is a Sierra-branded aftermarket seal manufactured as a cross-reference replacement for Mercury Marine 26-89238, not an original Mercury Marine part.

What is the UPC for the Sierra 18-2014 oil seal? The UPC for Sierra oil seal 18-2014 is 030999309600.

Does part number 18-2014 fit Bravo I stern drives? No. Sierra 18-2014 is specified for R/MR stern drives with Alpha I and for Alpha I SS stern drives; Bravo I applications use a different Sierra oil seal part number.

What is the WPB,L designation on the 18-2014 seal? WPB,L is the oil seal description code Sierra assigns to part number 18-2014 in its stern drive application listings.