396350 18-2656 Lower Unit Gearcase Seal O-ring Kit for Johnson Evinrude | JLM Marine

Lower Unit Gearcase Seal O-ring Kit 396350 – Fits Johnson Evinrude 8–15 HP Outboards

This Lower Unit Gearcase Seal O-ring Kit is engineered to fit Johnson Evinrude 8, 9.9, 10, and 15 HP outboard motors, covering both 2-stroke models (1974–2007) and 4-stroke models (1995–2004). It provides a complete seal solution for lower unit gearcase maintenance and rebuild applications.

Direct Replacements: OMC 396350 / 0396350, Sierra 18-2656, and 26-00077. This kit consolidates all essential seals and O-rings required for lower gearcase service in one package.

• Complete seal kit for lower unit gearcase rebuild
• Covers both 2-stroke and 4-stroke Johnson Evinrude engines
• All components shown in product image included

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.

Technical Specifications

Package Contents

This kit includes:

• 1 × Lower Gearcase Seal Kit

Note: The package contains all the seals and O-rings shown in the product image.

Installation Guide

1. Disconnect the lower unit from the outboard motor and drain all gearcase oil. Clean the exterior thoroughly to prevent contamination during disassembly.
2. Remove the propeller, shear pin, and any external hardware securing the lower unit housing. Mark the orientation of mating surfaces for reassembly.
3. Carefully disassemble the gearcase, noting the position of shims and thrust washers. Inspect all internal components for wear or damage.
4. Remove all old seals and O-rings from the gearcase housing using appropriate seal removal tools. Clean all sealing surfaces with solvent and inspect for scoring or corrosion.
5. Lubricate new seals and O-rings with marine-grade grease before installation. Install each seal square to its bore, ensuring proper orientation and seating depth.
6. Reassemble the gearcase components in reverse order, replacing shims and washers in their original positions. Torque all fasteners to manufacturer specifications.
7. Refill the gearcase with the correct type and quantity of gear oil through the lower fill plug. Monitor for air bubbles and ensure oil reaches the upper vent hole.
8. Reinstall the lower unit onto the outboard motor, aligning the driveshaft and water tube carefully. Secure all mounting hardware and torque to specification.
9. Run the engine in a test tank or on the water, checking for leaks around all seal points. Monitor gearcase temperature and shift operation for proper function.

Troubleshooting & FAQ

Q: How do I confirm this seal kit fits my specific Johnson or Evinrude engine?
A: Check the compatibility table above for your engine's HP rating, stroke type, and year range. Cross-reference your current part number (396350, 0396350, 18-2656, or 26-00077) to ensure proper fitment before ordering.

Q: How often should I replace the lower unit seals?
A: Replace lower unit seals during gearcase rebuilds or whenever you notice gear oil leaking, milky oil (indicating water intrusion), or during routine maintenance every 3–5 years depending on usage and operating conditions.

Q: What are the signs that my lower unit seals are failing?
A: Common symptoms include visible gear oil leaks around the lower unit, milky or contaminated gear oil, difficulty shifting gears, unusual noise from the gearcase, or overheating during operation.

Q: Can I reuse the old seals if they look okay?
A: No, always replace all seals and O-rings during gearcase service. Even if they appear intact, seals lose elasticity over time and may fail shortly after reassembly, leading to costly water damage or gear failure.

Q: What's the difference between this kit and the OEM Johnson/Evinrude kit?
A: This is an aftermarket replacement part built to OEM specifications using comparable materials. It provides the same seal function and fitment as the original OMC kit at a more competitive price point.

Q: Is this an OEM or aftermarket part?
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.