Sierra 18-2049 Oil Seal, Replaces Mercury Marine 26-32511, Fits Stern Drive Models 485, 888, 898/228

The Sierra 18-2049 Oil Seal is a white oil seal built as a direct equivalent to the Mercury Marine 26-32511 seal used in stern drive gear case assemblies. It measures 2.005 inches in outer diameter, fits a 1.250 inch shaft, and has a width of 0.388 inches, making it a precise fit for the applications it is designed to replace.

This seal is used in the gear case oil seal position (listed as position code GC in the parts breakdown) on stern drive units. It is designed to keep gear lubricant contained around the rotating shaft while keeping water out of the gear case, protecting internal gears and bearings from water intrusion and lubricant loss. Replacing a worn or hardened oil seal at this position is a routine maintenance step whenever a stern drive gear case is opened for service, or when gear lube is found to be milky or contaminated with water.

The Sierra 18-2049 is confirmed for use on stern drive models identified as 485, 888, and 898/228, each tied to specific serial number ranges. Always confirm your unit's serial number falls within the applicable range before ordering.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2049
• Color: White
• Outer Diameter: 2.005 inches
• Shaft Size: 1.250 inches
• Width: 0.388 inches
• Item Shape: Rectangular
• Weight: 0.07 pounds
• OEM Cross Reference: Mercury Marine 26-32511
• UPC: 808282257682

Fitment

• Stern drive model 485, serial number 4893835 and up
• Stern drive model 888, serial number 3106717 and up
• Stern drive model 898/228, serial number 4782330 to 6225576

Replaces (OEM)

• Mercury Marine 26-32511

Frequently Asked Questions

What does the Sierra 18-2049 oil seal replace? The Sierra 18-2049 is a direct equivalent to Mercury Marine part number 26-32511, so it can be used wherever that OEM number is called for.

What are the dimensions of this oil seal? The 18-2049 has an outer diameter of 2.005 inches, a shaft size of 1.250 inches, and a width of 0.388 inches.

Which stern drive models is the 18-2049 designed for? This seal is listed for stern drive models 485 (serial number 4893835 and up), 888 (serial number 3106717 and up), and 898/228 (serial number 4782330 to 6225576).

How do I know if my unit falls in the correct serial number range? Check the serial number tag on your stern drive unit against the ranges listed for the 18-2049: 4893835-and-up for model 485, 3106717-and-up for model 888, or 4782330 to 6225576 for model 898/228.

Is this a genuine Sierra part or a generic aftermarket seal? The 18-2049 is a Sierra branded oil seal, manufactured as a direct replacement for the Mercury Marine 26-32511 rather than a generic universal seal.

What color is the 18-2049 seal? This oil seal is white in color.

What position does this seal install in on the gear case? Within the stern drive parts breakdown, the 18-2049 is listed at the gear case oil seal position (position code GC).

Can I install the 18-2049 myself? Replacing the 18-2049 gear case oil seal is typically done whenever the stern drive gear case housing is opened for service, and it should be seated to the correct depth to seal properly around the 1.250 inch shaft.

Does the 18-2049 come with any additional hardware or seals? The 18-2049 is supplied as a single oil seal only; it does not include other gear case seals such as the 18-2056 or 18-2003 sometimes used in the same assembly.

How much does the Sierra 18-2049 weigh? The 18-2049 oil seal weighs 0.07 pounds.

Why would I need to replace this seal? A worn or hardened 18-2049 oil seal can allow water into the gear case or let gear lubricant escape, so it is commonly replaced if lubricant appears milky or the seal shows visible wear.