Gearcase Seal Kit – Fits Evinrude Johnson (Replaces 0439967, 439967)

$49.99

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Product Details

This aftermarket Gearcase Seal Kit is designed for specific Evinrude Johnson outboard engines. It provides a reliable seal for the outboard lower unit on models including OMC King Cobra 3.0L, V6, and V8 from 1986–1993, as well as select OMC Cobra models.

It serves as a direct cross-reference for numerous OEM and aftermarket part numbers, including Evinrude Johnson 0439967 and Sierra 18-2672.

Installs in the outboard lower unit.
Engineered to fit OMC Cobra models with the large (15" diameter) propeller bearing housing.
Replaces original seals to prevent gearcase leaks.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Evinrude Johnson	0439967
Evinrude Johnson	439967
Sierra	18-2672
Mercruiser	802415
Mercruiser	879034
Bombardier	0439967
Bombardier	439967
OMC	0778043
OMC	0984458
OMC	0985613
OMC	0987548

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This kit is compatible with specific OMC, Evinrude, and Johnson sterndrive and outboard models as detailed below.

Brand	Model	Rated HP	Years	OEM Part No.	Notes
OMC	King Cobra	3.0L	1990–1993	0439967 / 439967	Also compatible with V6 / V8 models (1986–1993) King Cobra. Fits Cobra models with the large propeller bearing housing (15" propeller diameter).
OMC	Cobra			0439967 / 439967	Non-King Cobra lower gearbox model.
Evinrude Johnson				0439967 / 439967

Technical Specs

Product Type: Gearcase Seal Kit
Installation: Outboard Lower Unit
Product Dimensions (L x W x H): 12.0 x 3.0 x 11.5 inches
Box Dimensions (L x W x H): 12.0 x 3.0 x 11.5 inches

What’s in the Box

1 x Gearcase Seal Kit (Replaces 0439967 / 439967)

Installation Notes

Disconnect the battery and ensure the engine is in a stable, secure position before beginning work.
Drain the gearcase lubricant completely into an appropriate container.
Disassemble the lower unit following the manufacturer's service manual to access the old seals.
Carefully remove all old seal components, gaskets, and O-rings, taking care not to scratch or damage the housing surfaces.
Thoroughly clean all mating surfaces of any old sealant or debris.
Lightly lubricate the new seals and O-rings with marine-grade grease before installation.
Using a suitable seal driver or press, install the new seals evenly and squarely into their respective bores until seated.
Reassemble the lower unit components in reverse order of disassembly, torquing fasteners to the specified values.
Refill the gearcase with the correct type and amount of new gear lubricant.
Before returning to service, check for any signs of leaks around the seals.

Troubleshooting & FAQ

How do I know if this seal kit fits my specific Cobra model?

This kit is designed for OMC Cobra models that have the large propeller bearing housing, which accommodates a 15-inch diameter propeller. It is not compatible with all Cobra models. Please verify your housing size or consult your service manual before ordering.

What are the signs of a failing gearcase seal?

Common signs include milky or water-contaminated gear lube (visible when draining), oil leaking from the lower unit around the propeller shaft or driveshaft, or a persistent sheen of oil on the water near your stern drive.

Can I replace just one seal instead of the whole kit?

It is highly recommended to replace all seals, gaskets, and O-rings in the kit at the same time. The seals wear at a similar rate, and replacing only one could lead to another failure soon after, requiring you to repeat the labor-intensive disassembly process.

Is a special tool required for installation?

Yes, proper installation often requires a seal driver set to press the new seals into the housing without damaging them. Using improper tools like sockets or hammers can deform the seal and lead to premature failure and leaks.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

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Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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