Lower Unit Gearcase Shift Shaft Oil Seal – Fits Yamaha 30-300 HP & Mercury 60-225 HP
This marine-grade oil seal is designed for lower unit gearcase applications on Yamaha outboards from 30 to 300 HP (1984–present) and select Mercury/Mariner models from 60 to 225 HP, primarily 4-stroke engines. It provides a direct replacement solution to prevent gearcase oil leaks around the shift shaft.
Engineered to meet or exceed OEM specifications, this seal ensures a precise fit and reliable performance in demanding saltwater and freshwater environments. It is a critical component for maintaining gearcase integrity and preventing water intrusion.
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Installation Type: Direct OEM replacement
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Compatible Fuel Type: Gasoline
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Included Components: One shift shaft oil seal
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Yamaha |
93106-09014-00 / 931060901400 |
| Mercury |
26-82257M |
| Sierra |
18-0267 |
| Mallory |
9-76423 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Yamaha owners, here’s a guide to help you identify your engine’s serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
Confirm your engine model/year in the table below. 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.
Yamaha Applications
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Yamaha |
Various |
30 |
2-Stroke |
1984–Present |
93106-09014-00 |
Gear housing application |
| Yamaha |
Various |
40-300 |
2-Stroke & 4-Stroke |
1984–Present |
93106-09014-00 |
Lower unit shift shaft seal |
Mercury Applications
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Mercury |
Various |
60 |
4-Stroke EFI |
2002–Present |
26-82257M |
2-cylinder models |
| Mercury |
Various |
225 |
4-Stroke EFI |
2004–Present |
26-82257M |
Specific models |
| Mercury |
Various |
75-115 |
4-Stroke |
2000–Present |
26-82257M |
Common application |
Technical Specifications
| Specification |
Value |
| Product Type |
Gear Housing Oil Seal |
| Installation |
Direct OEM replacement |
| Housing Material |
Rubber/Metal composite |
| Dimensions |
19mm bore × 9mm shaft diameter |
| Other Technical Attributes |
Designed for marine applications with saltwater resistance |
Package Contents
- 1 x Lower Unit Shift Shaft Oil Seal (Replaces 93106-09014-00 / 26-82257M)
Installation Guide
Professional installation is recommended. The general steps below are for reference; always consult your service manual for detailed instructions specific to your engine model.
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Drain the Gearcase: Position a drain pan under the lower unit and remove both the upper and lower drain screws to empty the gear oil.
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Remove the Lower Unit: Disconnect the shift linkage and remove the bolts securing the lower unit to the engine. Carefully lower it away from the engine.
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Access the Shift Shaft: With the lower unit on a workbench, locate the shift shaft assembly. You may need to remove the water pump housing to gain access.
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Remove the Old Seal: Carefully pry out the old, worn shift shaft oil seal using a seal puller or a flathead screwdriver. Take care not to scratch the housing or the shaft.
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Clean the Area: Thoroughly clean the seal housing and the shift shaft to remove any old sealant, debris, or corrosion.
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Install the New Seal: Lightly coat the outer edge of the new seal with a suitable sealant and the inner lip with marine grease. Press the new seal into place squarely using a socket or seal driver of the correct diameter.
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Reassemble: Reinstall the water pump assembly (if removed), reattach the lower unit to the engine, and connect the shift linkage.
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Refill Gear Oil: Fill the gearcase with the manufacturer-recommended gear lube until it flows from the upper vent hole, then reinstall both drain screws with new gaskets.
Troubleshooting & FAQ
How do I confirm this seal fits my engine?
First, check the Compatible Engine Models tables on this page. Cross-reference your engine's model, HP, and year. For Yamaha and Mercury owners, we provide links to serial number guides and parts catalogs to help you verify the exact OEM part number required before ordering.
What are the signs of a failing shift shaft oil seal?
The most common sign is a visible gear oil leak dripping from the lower unit, often near the front. Other indicators include a persistent sheen of oil on the water around your outboard or finding water in your gearcase oil during a routine change (milky or creamy appearance).
How often should this seal be replaced?
There is no fixed replacement interval for this seal. It should be inspected during any lower unit service, such as a water pump impeller change, or if you notice any signs of a leak. It is often replaced as a preventative measure when the lower unit is already disassembled.
OEM vs. Aftermarket?
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.
How fast do you ship and how much does it cost?
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.
What is your warranty and return policy?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.