Gearcase Lower Unit Seal Kit – Fits Johnson/Evinrude 8–15 HP (Replaces 0396350, 0777568)
Gearcase Lower Unit Seal Kit – Fits Johnson/Evinrude 8–15 HP (Replaces 0396350, 0777568) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
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Gearcase Lower Unit Seal Kit – Fits Johnson/Evinrude 8–15 HP (Replaces 0396350, 0777568) is backordered and will ship as soon as it is back in stock.
Product Details
This complete aftermarket Gearcase Lower Unit Seal Kit – Fits Johnson/Evinrude 8–15 HP Outboards contains all necessary seals, o-rings, and hardware to rebuild the lower unit on Johnson/Evinrude 8–15 HP 2-Stroke (1974–2007) and 4-Stroke (1995–2004) outboard motors.
It serves as a direct replacement for OEM part numbers 0396350 and 0777568, and interchanges with aftermarket references including Sierra 18-2656, GLM 87602, and Mallory 9-74100.
- Restores sealing integrity to prevent water intrusion and oil leaks.
- Includes a comprehensive set of components for a standard lower unit reseal.
- Professional installation is recommended for optimal performance and longevity.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Johnson/Evinrude | 0396350 | Superseded by 0777568 |
| Johnson/Evinrude | 0777568 | Current OEM Part Number |
| Sierra | 18-2656 | Aftermarket |
| GLM | 87602 | Aftermarket |
| Mallory Marine | 9-74100 | Aftermarket |
| SEI Marine | 95-361-11K | Aftermarket |
| QuickMarine | 396350 | Aftermarket |
| Mhrxusd | 0396350 | Aftermarket |
Engine & Model Compatibility
Confirm your engine model and year in the table below. This kit is designed for a wide range of Johnson and Evinrude 2-stroke and 4-stroke motors from 8 to 15 HP.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | Multiple | 8 | 4-Stroke | 1995–2004 | 0396350/0777568 | |
| Johnson/Evinrude | Multiple | 9.9 | 2-Stroke | 1974–2007 | 0396350/0777568 | |
| Johnson/Evinrude | Multiple | 9.9 | 4-Stroke | 1995–2004 | 0396350/0777568 | |
| Johnson/Evinrude | Multiple | 10 | 2-Stroke | 1974–2007 | 0396350/0777568 | |
| Johnson/Evinrude | Multiple | 15 | 2-Stroke | 1974–2007 | 0396350/0777568 | |
| Johnson/Evinrude | Multiple | 15 | 4-Stroke | 1995–2004 | 0396350/0777568 |
Technical Specs
- Product Type
- Lower Unit/Gearcase Seal Kit
- Installation
- Professional recommended
- Weight
- 0.068 kg (2.4 oz)
- Warranty
- 1-year against manufacturing defects
- Other Technical Attributes
- ISO 9001/9002 certified manufacturing (aftermarket)
What’s in the Box
- 1 x Oil Seal (0318972)
- 1 x Oil Seal (0321480)
- 1 x Oil Seal (0342247)
- 1 x Drain/Fill Plug Washer (0311598)
- 1 x O-Ring (0301877)
- 1 x O-Ring (0308627)
- 1 x O-Ring (0307853)
- 1 x O-Ring (0319085)
- 1 x Washer (0332584)
- 1 x Fill and Drain Plug Screw (0307551)
- 1 x Shift Rod Washer (0321738)
Installation Notes
- Disconnect the battery and spark plug wires for safety.
- Drain the gearcase oil by removing the lower and upper drain/fill plugs. Inspect oil for water (milky) or metal shavings.
- Remove the propeller and associated hardware.
- Unbolt and carefully separate the lower unit (gearcase) from the outboard's upper housing. The shift linkage may need to be disconnected.
- Disassemble components as required to access the seals, including the water pump housing and bearing carriers. Keep parts organized.
- Carefully remove all old seals, o-rings, and gaskets using appropriate pullers to avoid scratching metal surfaces.
- Thoroughly clean all sealing surfaces and component housings, removing any old sealant, corrosion, or debris.
- Install the new seals and o-rings from the kit. Lightly lubricate new seals with marine grease to ease installation.
- Reassemble the gearcase, ensuring all bolts are torqued to manufacturer specifications.
- Reattach the lower unit, ensuring the driveshaft, water tube, and shift shaft are correctly aligned.
- Refill the gearcase with new marine gear lubricant. Reinstall both drain/fill plugs with new washers.
- Reinstall the propeller and test the engine in a water source, checking for leaks after operation.
Troubleshooting & FAQ
How do I know if my gearcase seals are failing?
Common signs include milky, water-contaminated gear oil (check via the drain plug), visible oil leaks around the propeller shaft or gearcase seams, or a frequent need to top off gear lube without visible leaks.
Will this kit fit my specific engine model?
This kit fits the HP and year ranges specified in the compatibility table. For a guaranteed match, always verify your engine’s OEM part number against those listed (0396350, 0777568) before ordering.
Is professional installation really necessary?
While DIY installation is possible for experienced mechanics, we strongly recommend professional installation. Improper seating or damage to a seal during installation can cause premature failure and lead to catastrophic gearcase damage.
How often should gearcase seals be replaced?
Inspect your gear lube at least once a season. Seals should be replaced immediately if you notice any leaks or water contamination. As preventative maintenance, consider replacement every 5–7 years, depending on usage and operating conditions.
What is the most common cause of gearcase seal failure?
The leading cause of premature failure is damage from fishing line or other debris wrapping around the propeller shaft, which cuts into the seal and allows water to enter. Normal wear and age are also factors.
Can I reuse any of the old seals or gaskets?
No. Always use all new seals, o-rings, and washers provided in the kit. Old components can be hardened, cracked, or deformed and will not create a reliable, long-lasting seal.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact our support team with your order details. Returns are accepted within our standard window for unused items in original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchase. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement component, not an OEM part.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — Our direct-sourcing model provides fair pricing without compromising on materials or quality control.
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