Drain/Fill Plug Washer – Fits Johnson/Evinrude/OMC Engines (Replaces 311598)

Drain/Fill Plug Washer – Fits Johnson/Evinrude/OMC Engines (Replaces 311598)

This high-quality nylon washer provides a secure seal for the drain and fill plugs on a wide range of outboard and sterndrive lower units. It is designed to fit various Johnson/Evinrude outboards from the early 1970s through 2006, as well as multiple OMC Cobra and Volvo Penta sterndrive models.

This component directly replaces multiple OEM and aftermarket part numbers, ensuring broad compatibility and reliable performance. It is crucial for preventing water intrusion and gear lube leaks in the gearcase.

• Material: Durable Nylon construction for a reliable press fit.
• Compatibility: Fits drain/fill screws with 10mm threads.
• Function: Creates a tight seal for lower unit drain and fill screws.

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 Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson/Evinrude Serial Number Guide.

Johnson/Evinrude Outboards

Volvo Penta Sterndrives

OMC Stern Drives

Technical Specifications

Package Contents

• 1 x Drain/Fill Screw Washer (Replaces 311598/0311598)

This product is sold as a single washer. Also available in 5-packs and 50-packs.

Installation Guide

1. Locate the lower unit drain and fill plugs on your engine or sterndrive. You will need two new washers for a complete gear lube change.
2. Place a drain pan under the lower unit. Remove the bottom (drain) screw first, then the upper (fill/vent) screw to allow the oil to drain completely.
3. Remove the old washers from both screws. Clean the screw threads and the sealing surfaces on the gearcase to remove any old gasket material or debris.
4. Press one new washer firmly onto each of the drain and fill screws.
5. Reinstall the upper (fill/vent) screw first, but do not fully tighten. This prevents air from entering while you fill the gearcase.
6. Using a gear lube pump, fill the lower unit through the bottom drain hole until fluid flows out of the upper vent hole.
7. Install the bottom (drain) screw and tighten it securely.
8. Remove the gear lube pump and quickly reinstall the upper (fill/vent) screw, tightening it securely.
9. Tighten both screws to the manufacturer's recommended torque specification. Do not overtighten, as this can damage the washer or gearcase.
10. Clean any excess oil and check for leaks after a few minutes.

Troubleshooting & FAQ

Q: How can I confirm this washer fits my specific engine?

A: The best way is to match your engine's original part number to one of the numbers listed in our Part Number Cross-Reference table. You can also check your engine's model and year against the compatibility tables on this page.

Q: What is the washer made from?

A: This washer is made from high-quality Nylon, designed to provide a durable and reliable seal that presses onto the screw securely.

Q: How often should I replace my drain/fill plug washers?

A: It is strongly recommended to use a new washer every time you change your lower unit gear lube. Reusing old washers can lead to improper sealing and water intrusion, which can cause catastrophic gearcase failure.

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.