396355 18-2659 Lower Unit Seal Kit for Johnson Evinrude 40HP 48HP 50HP 55HP 60HP 75HP | JLM Marine

Lower Unit Seal Kit for Johnson/Evinrude 40HP 48HP 50HP 55HP 60HP 75HP | 396355 18-2659

This comprehensive lower unit seal kit is engineered to fit Johnson/Evinrude outboard engines ranging from 40HP to 75HP manufactured between 1986 and 1988. Designed specifically for 2-cylinder models and 75HP small gearcase (short shaft) configurations, this kit provides all the essential seals needed for complete lower unit gearcase maintenance and rebuild.

This aftermarket replacement directly replaces original equipment part numbers including Johnson/Evinrude 396355, Sierra 18-2659, GLM 87603, and Mallory 9-74102, ensuring broad compatibility and reliable performance across multiple sourcing options.

• Complete seal kit for lower unit gearcase service
• Fits both 2-cylinder models (40-60HP) and small gearcase 75HP engines
• All necessary seals included for comprehensive rebuild

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 × Complete Lower Unit Seal Kit

The package contains all the seals and components shown in the product images.

Installation Guide

1. Disconnect the battery and remove the outboard lower unit from the engine following your service manual procedures.
2. Drain all gear oil from the lower unit gearcase completely and dispose of properly.
3. Disassemble the lower unit carefully, documenting the position and orientation of all components for reassembly.
4. Remove all old seals, gaskets, and O-rings from the gearcase housing and propeller shaft. Clean all sealing surfaces thoroughly with a suitable solvent and inspect for wear or damage.
5. Install new seals from the kit according to the manufacturer's specifications, ensuring proper orientation and seating depth.
6. Apply marine-grade grease to seal lips where specified in your service manual to prevent damage during initial startup.
7. Reassemble the lower unit components in reverse order of disassembly, torquing all fasteners to factory specifications.
8. Reinstall the lower unit onto the engine, ensuring proper alignment and secure mounting.
9. Refill the gearcase with the correct type and quantity of marine gear oil as specified for your engine model.
10. Check for leaks by running the engine in a test tank or on-water for several minutes.
11. Recheck the gear oil level after initial operation and top off if necessary.
12. Dispose of all old seals and used gear oil in accordance with local environmental regulations.

Troubleshooting & FAQ

Q: How do I confirm this seal kit fits my specific Johnson or Evinrude engine?
A: Verify that your engine matches the specifications listed in the Compatible Engine Models table—specifically 40-60HP 2-cylinder models or 75HP small gearcase (short shaft) built between 1986-1988. Cross-reference your original part number (396355) or check your engine's serial number using our guide linked above.

Q: What are the signs that my lower unit seals need replacement?
A: Common symptoms include gear oil leaking from the lower unit, milky or contaminated gear oil (indicating water intrusion), unusual noise from the gearcase, or difficulty shifting gears. If you notice any of these issues, inspect and replace seals promptly to prevent further damage.

Q: How often should I replace the lower unit seals?
A: Seal replacement intervals depend on usage and operating conditions. Inspect seals annually or every 100 hours of operation, whichever comes first. Replace immediately if you detect leaks, water contamination in the gear oil, or during any lower unit rebuild or repair.

Q: Can I install this seal kit myself or do I need a professional?
A: Lower unit seal replacement requires mechanical aptitude, specialized tools, and knowledge of proper torque specifications. If you have experience with outboard maintenance and access to a service manual, DIY installation is possible. Otherwise, professional installation is strongly recommended to ensure proper sealing and prevent costly damage.

Q: What's the difference between this aftermarket seal kit and the OEM version?
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.