Lower Unit Seal Kit – Fits Johnson/Evinrude 85/100/125 HP Large Prop Shaft 1971-1972 (Replaces 18-2691)

Lower Unit Seal Kit – Fits Johnson/Evinrude 85/100/125 HP Large Prop Shaft 1971-1972

This lower unit seal kit is designed for Johnson/Evinrude 85, 100, and 125 HP outboard engines (1971–1972) equipped with the large propeller shaft. It provides the necessary components to restore seals and prevent water intrusion or oil leaks in the gearcase.

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

• Engine Compatibility: Fits specific 2-Stroke Johnson/Evinrude V4 engines from 1971-1972.
• Installation Type: Direct replacement for OEM and aftermarket equivalents.
• Key Feature: Specifically for models using the 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

Package Contents

• 1 x Solenoid Cover Gasket (Replaces 0314876, 0777572, 18-2874)
• 2 x Oil Seal (Replaces 0330137, 0310600, 0321463, and others)
• 2 x Oil Seal (Replaces 0321466, 0313337, 0318223, and others)
• 2 x Drain/Fill Plug Washer (Replaces 0311598, 3852105, 18-4248)
• 4 x O-Ring Seal (Replaces 0317178, 0777520, 18-7109)
• 1 x O-Ring (Replaces 0313446, 0765593, 18-7127)
• 1 x O-Ring (Replaces 0354731, 0314728, 0777532, and others)

Installation Guide

1. Begin by draining the gearcase oil completely into a suitable container.
2. Remove the propeller and unbolt the lower unit from the outboard motor's leg.
3. Disassemble the gearcase to gain access to the driveshaft and prop shaft seals. Pay close attention to the order and orientation of components as you remove them.
4. Carefully extract the old, worn seals and O-rings from the gearcase housing and carrier, avoiding scratches to the sealing surfaces.
5. Thoroughly clean all sealing surfaces, removing any old adhesive, corrosion, or debris.
6. Lightly lubricate the new seals and O-rings with marine grease before installation. This aids in seating and prevents damage.
7. Using an appropriate driver or socket, press the new seals into place until they are fully and evenly seated. Ensure they face the correct direction to hold pressure.
8. Carefully reassemble the gearcase components in the reverse order of disassembly.
9. Re-install the lower unit onto the engine and attach the propeller.
10. Refill the gearcase with manufacturer-specified lower unit oil to the correct level, using new drain/fill plug washers from the kit.
11. Before operating in water, check for any signs of oil leaks around the newly installed seals and plugs.

Troubleshooting & FAQ

Q: How can I be sure this seal kit fits my specific Johnson/Evinrude engine?

A: This kit is specifically for 85, 100, and 125 HP Johnson/Evinrude models from 1971-1972 that use the large prop shaft. The most reliable method is to verify your engine's model and year against our "Compatible Engine Models" table. Using our Johnson/Evinrude Serial Number Guide can also help confirm your engine's details.

Q: What are the common signs that my lower unit seals are failing?

A: The most common sign is milky or cloudy gearcase oil, which indicates water has mixed with the oil. Other symptoms include visible oil leaks around the propeller shaft, water dripping from the gearcase, or finding you need to frequently top off the gear oil.

Q: Are special tools required for this installation?

A: While the job can be done with standard mechanic's tools, using a dedicated seal puller for removal and a proper seal driver set for installation is highly recommended. These tools help prevent scoring the gearcase housing or damaging the new seals upon entry.

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.