18-2002 Marine Oil Seals, 2-Pack – Fits Mercury/MerCruiser 100–250 HP Outboards and Alpha/Bravo Drives

Product Details

This 2-pack of 18-2002 marine oil seals is designed for reliable sealing in compatible marine gear-housing and lower-unit applications. The seals are commonly used on select Mercury and MerCruiser 100–250 HP outboards and Alpha One, Alpha One SS, and Bravo stern drives. Always confirm the exact model, year, serial number, and original part number before ordering.

Commonly cross-referenced numbers include Mercury 26-76868 and 26-30550, Sierra 18-2002, GLM 85130, Honda 91252-ZW1-003, Johnson/Evinrude/OMC 0320862 or 320862, Mallory 9-76202, and Chrysler/Force/US Marine 26-76868. These references are provided for identification and should be verified against the service information for your specific application.

• Two replacement oil seals included.
• Commonly installed in prop-shaft or drive-shaft lower-unit sealing applications.
• Machined housing design for proper positioning in the seal bore.
• Aftermarket replacement part; not an OEM component.

Part Number Matrix

Use the following references to help compare the seal with your original part. Number cross-references do not replace model and serial-number verification.

Engine & Model Compatibility

The applications below are reference fitments associated with the listed OEM number. Confirm your engine model and serial number before installation, because fitment can vary by production range and gearcase configuration.

Technical Specs

Product Type

Gear-housing oil seal

Quantity

2 oil seals

Installation Location

Drive shaft or gear housing, depending on application

Dimensions

Outside diameter: 43 mm (1.692 in); inside diameter/shaft size: 30.2 mm (1.188 in); width: 6.4 mm (0.250 in)

Housing

Machined

Common Application

Lower-unit prop-shaft or drive-shaft sealing

Weight

Approximately 0.04 lb (0.018 kg)

What’s in the Box

• 2 x 18-2002 marine oil seal

Installation Notes

1. Disconnect the battery and secure the engine before beginning work.
2. Drain the gearcase lubricant into an approved container.
3. Remove the propeller, gearcase components, and other parts blocking access to the seal.
4. Remove the old seal with a suitable seal puller, taking care not to scratch the housing.
5. Clean the seal bore and remove old sealant, corrosion, and debris.
6. Lightly lubricate the new seal lip and outer edge with an appropriate marine lubricant.
7. Position the seal squarely and press it evenly into the bore with a suitable seal driver or socket. Seat it to the position specified by the service manual.
8. Reassemble the gearcase and propeller in the reverse order of removal.
9. Refill the gearcase with the manufacturer-specified lubricant.
10. After operation, inspect the area for leaks and verify the gear lubricant is not contaminated with water.

Troubleshooting & FAQ

Safety & Important Information

• Verify the model, year, serial number, dimensions, and original part number before ordering.
• Do not install a seal that differs in size, lip orientation, or construction from the specification for your gearcase.
• Professional installation is recommended when servicing the lower unit or gearcase.
• Follow the engine manufacturer's service procedures and lubricant requirements.

About Sea Sierra

• Marine Replacement Parts — Parts selected for common service and repair applications.
• Fitment-Focused Listings — Reference numbers and application information are provided to help with product identification.
• Customer Support — Contact support with your engine model, serial number, and original part information when fitment assistance is needed.