Lower Unit Seal Kit – Fits Johnson/Evinrude 85/100/125 HP (Replaces 18-2691, 87611)

Lower Unit Seal Kit – Fits Johnson/Evinrude 85/100/125 HP (Replaces 18-2691, 87611)

This lower unit seal kit is designed for Johnson/Evinrude 85, 100, and 125 HP 2-Stroke outboards from 1971–1972, specifically for models equipped with a large prop shaft. It provides the necessary components to restore the integrity of the gearcase and prevent water intrusion.

This kit serves as a direct replacement for several aftermarket and OEM equivalent part numbers, including Sierra 18-2691, GLM 87611, and Mallory 9-74114.

• Installation Type: Direct replacement for a precise fit.
• Application: Specifically designed for models with a large prop shaft.

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

Installation Guide

1. Drain the gearcase oil: Remove the drain and vent screws and allow all oil to drain completely.
2. Remove the lower unit: Unbolt and carefully detach the entire gearcase assembly from the outboard's midsection.
3. Disassemble as needed: Remove the propeller, followed by the bearing carrier assembly, to gain access to the prop shaft seals.
4. Extract old seals: Carefully remove all old seals, o-rings, and gaskets from the gearcase and bearing carrier. Pay close attention to their orientation.
5. Clean all surfaces: Thoroughly clean the sealing surfaces, ensuring they are completely free of old gasket material, sealant, and corrosion.
6. Lubricate new components: Lightly coat the new seals and o-rings with marine grease before installation to prevent damage.
7. Install new seals: Carefully press the new seals and o-rings into place, making sure they are seated correctly and uniformly.
8. Reassemble components: Reinstall the bearing carrier and propeller, torquing fasteners to the manufacturer's specifications.
9. Reattach the lower unit: Secure the lower unit back onto the outboard.
10. Refill with oil: Fill the gearcase with the recommended type and amount of lower unit lubricant. Reinstall the vent and drain screws with new gaskets if supplied.
11. Check for leaks: After refilling, check for any signs of oil leakage around the seals before operating the engine.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my engine?
A: This kit is specifically for Johnson/Evinrude 85, 100, and 125 HP 2-stroke outboards from 1971-1972 with a large prop shaft. Please check your engine's model number and year against the compatibility list. It is critical to confirm your model has the large prop shaft, as a standard version will not fit.

Q: What are the signs that my lower unit seals need replacing?
A: The most common sign is milky, discolored gear oil, which indicates water has mixed with the oil. You may also notice oil leaking from the prop shaft area or an unusual amount of metal shavings on the magnetic drain plug.

Q: Is this a complete kit for the job?
A: This kit includes the primary seals, o-rings, and gaskets needed for a standard lower unit reseal. We recommend comparing the product images to your old parts to ensure it contains everything necessary for your specific repair.

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.