Sierra 18-0580 Oil Seal, Replaces Mercury/Chrysler/Force 26-41132

The Sierra 18-0580 Oil Seal is a round, white oil seal engineered as a direct interchange for the 26-41132 seal used across multiple outboard powerhead applications. It is built to the same critical dimensions as the original equipment part it replaces, with a 1.250 inch outer diameter, a 0.750 inch shaft size, and a 0.312 inch width, so it seats and seals correctly in the same bore and against the same shaft as the part it replaces. As a powerhead seal, its primary job is to keep lubricating oil contained around a rotating shaft while excluding water and debris from the crankcase area, protecting internal components from contamination and oil loss.

Sierra manufactures this seal to meet or exceed the performance of the original equipment part, making it a straightforward replacement when an outboard's powerhead seal has hardened, cracked, or begun to leak. Because it is sold as a single seal, it drops in wherever a 26-41132 (or its cross-referenced equivalents) is specified, without requiring any modification to the surrounding housing.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-0580
• OEM Cross Reference: 26-41132
• Outer Diameter: 1.250 inches
• Shaft Size: 0.750 inches
• Width: 0.312 inches
• Color: White
• Shape: Round
• Weight: 0.02 pounds
• Application: Mercury Outboard Powerhead Seals and O-Rings

Fitment

Fits applications originally specified with a 26-41132 oil seal or its cross-referenced equivalents.

Replaces (OEM)

• 26-41132

Frequently Asked Questions

What OEM part number does the Sierra 18-0580 oil seal replace? It replaces OEM number 26-41132. The Sierra 18-0580 oil seal is built to the same dimensions as that original part so it installs as a direct swap.

What are the dimensions of the Sierra 18-0580 oil seal? The Sierra 18-0580 measures 1.250 inches on the outer diameter, has a 0.750 inch shaft size, and is 0.312 inches wide.

Is the Sierra 18-0580 a genuine Sierra part or aftermarket? It is a Sierra-manufactured replacement seal, not a part sold under the original equipment manufacturer's own brand. Sierra states it meets or exceeds the performance of the original 26-41132 seal it replaces.

What color and shape is the 18-0580 oil seal? It is a round seal finished in white, matching the standard oil seal shape used in outboard powerhead applications.

How much does the Sierra 18-0580 oil seal weigh? The seal weighs 0.02 pounds, consistent with a small, single powerhead seal.

What is the purpose of the 18-0580 oil seal in an outboard powerhead? This seal keeps lubricating oil contained around a rotating shaft while keeping water and debris out of the crankcase area, protecting internal powerhead components from contamination and oil loss.

Does the Sierra 18-0580 come as a single seal or a kit? It is sold as a single oil seal, part number 18-0580, not as part of a multi-seal kit.

Will the Sierra 18-0580 fit if my part is marked 26-41132? Yes, a part marked 26-41132 is the OEM number that the Sierra 18-0580 oil seal is designed to replace directly.

How do I know if I need to replace an oil seal like the 18-0580? Signs of a failing powerhead oil seal include visible oil leakage around the shaft, water intrusion into the crankcase, or a hardened and cracked seal surface; the 18-0580 addresses these issues as a direct replacement for the 26-41132 seal.

What category of part is the Sierra 18-0580? The 18-0580 is categorized as a powerhead seal, part of Sierra's outboard powerhead seals and O-rings line.