Gearcase Drain Plug Gasket Washer – Fits Mercury Marine/Mercruiser Outboards & Sterndrives (Replaces 26-830749)

Gearcase Drain Plug Gasket Washer – Fits Mercury Marine/Mercruiser Outboards & Sterndrives (Replaces 26-830749)

This gearcase drain plug gasket is engineered to fit a wide range of Mercury Marine and Mercruiser outboards and sterndrives that use 3/8-16 drain and fill screws. It provides a reliable seal for lower unit maintenance. Please note, it is not compatible with models of Japanese origin.

As a direct replacement for Mercury part numbers 26-830749 and the superseded 8M0204693, this gasket ensures proper fit and function. Its distinct yellow color identifies it as the modern, rubber-coated steel core design, which offers enhanced durability and sealing compared to older blue fiber gaskets.

• Designed for a direct, leak-free fit with 3/8-16 drain and fill screws.
• Constructed from a tear-resistant, rubber-coated stainless steel core for superior oil and corrosion resistance.
• Replaces OEM part numbers: 26-830749, 8M0204693.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Mercury Marine & Mercruiser

Technical Specifications

Package Contents

Package contents vary by the selected manufacturer. Please verify the quantity before purchase:

• PEUTIER: 6 x Gearcase Drain Plug Seal Washers (26-830749)
• RARAYC: 6 x Gearcase Drain Plug Seal Washers (26-830749)
• Quicksilver OEM: 2 x Gearcase Drain Plug Seal Washers (26-830749)
• Isslly: 10 x Gearcase Drain Plug Seal Washers (26-830749)

Installation Guide

1. Position a suitable drain pan under the lower unit/gearcase.
2. Using a large, flathead screwdriver, carefully remove the upper (vent) and lower (drain) gearcase screws.
3. Allow the gear lube to drain completely. Inspect the oil for any signs of water intrusion (milky appearance) or excessive metal particles.
4. Remove the old gaskets from both screws and discard them.
5. Thoroughly clean the threads of both screws and the sealing surfaces around the screw holes on the gearcase.
6. Place a new gasket onto each of the drain and vent screws.
7. Insert your gear lube pump fitting into the lower drain hole.
8. Pump fresh gear lube into the gearcase until it begins to flow out of the upper vent screw hole. This ensures the gearcase is full and free of air pockets.
9. Reinstall the upper vent screw with its new gasket and tighten it securely.
10. Quickly remove the lube pump fitting and reinstall the lower drain screw with its new gasket.
11. Tighten both screws to the manufacturer's recommended torque. Do not overtighten, as this can damage the new gasket or the gearcase housing.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my Mercruiser sterndrive?
A: This gasket fits most Mercury and Mercruiser drives with a 3/8-16 drain/fill screw, including the Alpha One (Gen II) and Bravo series. Always verify your model and serial number against the compatibility chart above. It is not designed for units of Japanese origin.

Q: What is the difference between this yellow gasket and the old blue one?
A: The yellow gasket is the modern replacement for the older blue fiber gasket. It features a more durable construction with a stainless steel core coated in rubber, providing a superior seal and better resistance to tearing and corrosion during installation and removal.

Q: How often should I replace my gearcase drain gaskets?
A: It is best practice to replace the drain and fill screw gaskets every time you change your gear lube. This is typically recommended annually or every 100 hours of operation, whichever comes first, to ensure a perfect, leak-free seal.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.