Lower Unit Seal Kit - Fits Tohatsu/Mercury/Nissan 4-6 HP Outboards (Replaces 369-87321-0/369873210)

Lower Unit Seal Kit - Fits Tohatsu/Mercury/Nissan 4-6 HP Outboards (Replaces 369-87321-0)

This lower unit seal kit is designed for a range of Tohatsu, Nissan, and Mercury 4-6 HP outboard motors. It fits various 2-stroke (M5B/NS5B) and 4-stroke (MFS4/MFS5/MFS6, NSF4/NSF5/NSF6) models from 2002–2014. It is also compatible with Mercury 4HP, 5HP, and 6HP 4-stroke outboards, which are often rebranded Tohatsu engines.

This kit serves as a direct replacement for Tohatsu part numbers 369-87321-0, 369873210, 369873210M, 369873212M and Mercury part numbers 27-8M0155392, 95220A2, 27-8M0134073, 8M0082882, 27-8M0188431.

• Installation: Direct replacement for a complete gearcase/lower unit service.
• Materials: Includes non-asbestos paper gaskets, rubber o-rings, and synthetic seals.
• Compatibility: Fits specific gasoline Tohatsu, Nissan, and Mercury models.

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 Tohatsu and Nissan engines, cross-reference your model and year to ensure compatibility.

For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

This kit contains the following components:

• 1 x Gasket (332-60006-0)
• 1 x Oil Seal (369-60111-0)
• 1 x O-Ring (345-65015-0)
• 1 x Pump Case Gasket - Upper (369-65018-0)
• 1 x Pump Guide Plate Gasket (369-65029-0)
• 1 x Oil Seal (369-60223-0)
• 1 x Pump Case Gasket - Lower (369-65020-0)
• 1 x O-Ring (369-66021-1)
• 1 x O-Ring (332-66032-0)

Installation Guide

Professional installation is recommended. The general steps for replacement are as follows:

1. Drain Oil: Start by completely draining the gearcase oil.
2. Remove Lower Unit: Unbolt and detach the lower unit assembly from the outboard engine leg.
3. Disassemble Gearcase: Carefully disassemble the gearcase to access the water pump, driveshaft, and prop shaft components. This will expose the seals and gaskets.
4. Remove Old Seals: Systematically remove all old gaskets, seals, and O-rings. Thoroughly clean all mating surfaces to ensure they are free of old material and corrosion.
5. Install New Components: Install the new seals and gaskets from the kit in their correct locations. Be sure to orient seals correctly and apply a light coat of marine grease where appropriate.
6. Reassemble & Reinstall: Reassemble the gearcase and reinstall the lower unit onto the outboard.
7. Refill Oil: Refill the gearcase with the manufacturer-specified lower unit oil to the correct level.
8. Check for Leaks: Before operating the outboard on the water, check for any oil or water leaks around the newly sealed areas.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my engine?

A: Check the "Compatible Engine Models" and "Part Number Cross-Reference" tables. This kit is for specific Tohatsu, Nissan, and Mercury 4-6 HP models. Verifying your engine's model, year, and original part number is essential.

Q: What are the signs that my lower unit seals need replacing?

A: Common signs include water found in the gearcase oil (milky or cloudy appearance), oil leaking from the lower unit (especially around the propeller assembly), or visible damage and cracking on the old seals during an inspection.

Q: How often should I replace the lower unit seals?

A: It is good practice to inspect your lower unit seals annually and replace them whenever you service the water pump or notice any signs of leakage or wear. As a preventative measure, replacing them every few seasons can help avoid catastrophic gear 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.

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.