Propeller Shaft Oil Seal – Fits Mercury Outboard 30–150 HP (Replaces 26-70081, 26-8M0205729)
This propeller shaft oil seal is designed for a wide range of Mercury Marine outboards, from 30 to 150 HP, including various 2-Stroke and 4-Stroke models produced over several decades. It also fits select Honda Marine 75–90 HP 4-Stroke outboards, such as the BF75 and BF90 series from 1997–1998.
This seal serves as a direct replacement for Mercury parts 26-70081 and 26-8M0205729, Honda part 91255-ZW1-003, and several other aftermarket equivalents.
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Durable Construction: Made from high-quality Nitrile Rubber for resistance to saltwater, oil, and extreme temperatures.
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Dual-Lip Design: Features a dual-lip construction that provides a primary seal against oil and a secondary dust lip to protect against contaminants.
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Precise Fit: Engineered to meet OEM specifications for a direct, reliable fit in the lower unit gear housing.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
26-70081 |
| Mercury |
26-8M0205729 |
| Honda |
91255-ZW1-003 |
| Force/US Marine |
26-70081 |
| Sierra |
18-2053 |
| GLM |
85530 |
| Mallory |
9-76115 |
Compatible Engine Models
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.
Confirm your engine model/year in the table below.
Mercury/Mariner Models
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Mercury |
V-200 |
200 |
2-Stroke |
1978-1988 |
26-70081 |
Without Driveshaft Nut |
| Mercury |
V-150/V-1500 |
150 |
2-Stroke |
1978-1985 |
26-70081 |
V-6 Series incl. XR-2, Marathon, Magnum, Work models |
Force Models
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Force |
Standard |
90 |
2-Stroke |
1995-1999 |
26-70081 |
Multiple clutch types |
| Force |
Standard |
120 |
2-Stroke |
1995-1999 |
26-70081 |
Multiple clutch types |
| Force |
Standard |
75 |
2-Stroke |
1999 |
26-70081 |
|
Honda Models
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Honda |
BF75AT |
75 |
4-Stroke |
1997-1998 |
91255-ZW1-003 |
LHTA, LRTA & XRTA variants |
| Honda |
BF90AT |
90 |
4-Stroke |
1997-1998 |
91255-ZW1-003 |
LHTA, LRTA & XRTA variants |
Technical Specifications
| Specification |
Value |
| Product Type |
Propeller Shaft Oil Seal |
| Installation Location |
Lower Unit / Gear Housing (Propeller Shaft) |
| Housing Material |
Nitrile Rubber |
| Dimensions |
OD: 45mm (1.76"), ID: 30mm (1.185"), Width: 9.1mm (0.35") |
| Temperature Range |
-30°C to 120°C (-22°F to 248°F) |
| Construction |
Dual-lip design with primary sealing and dust protection |
| Application |
Marine engine maintenance and repair |
| Features |
Saltwater, oil, and temperature resistant |
Package Contents
- 1 x Oil Seal (26-8M0205729 / 26-70081) OR
- 2 x Oil Seal (26-8M0205729 / 26-70081)
Note: Package quantity varies by seller. Some listings include a single seal, while others offer a two-pack. Please verify the quantity in your selected package.
Installation Guide
Professional installation is recommended. The following is a general guide:
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Drain Gearcase Oil: Position a drain pan under the lower unit and remove the upper and lower gearcase drain screws to drain the oil completely.
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Remove Propeller: Straighten the cotter pin tabs, remove the pin, nut, and washers to slide the propeller off the shaft.
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Remove Bearing Carrier: Depending on your model, remove the bolts or retainer holding the propeller shaft bearing carrier in place. Use a puller tool if necessary to extract the carrier assembly.
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Extract Old Seals: Carefully pry the old oil seals out from the bearing carrier. Take care not to scratch or damage the housing surfaces.
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Clean and Inspect: Thoroughly clean the seal housing in the bearing carrier. Inspect it for any burrs, corrosion, or damage that could affect the new seal.
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Install New Seals: Lubricate the outer edge of the new seals with a thin layer of marine grease. Use a seal driver or a socket of the correct diameter to press the new seals evenly into the carrier until they are properly seated. Ensure they are facing the correct direction.
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Reassemble: Re-install the bearing carrier, propeller, and associated hardware. Torque all bolts and nuts to the manufacturer's specified values.
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Refill Gearcase: Fill the lower unit with fresh gear lube through the bottom drain hole until it seeps out of the upper vent hole. Re-install both drain/vent screws with new gaskets.
Troubleshooting & FAQ
How do I confirm this fits my engine?
First, check the Compatible Engine Models table on this page. If your model is listed, cross-reference the OEM part number (e.g., 26-70081, 91255-ZW1-003) with your engine's parts diagram. It is critical to also visually compare the product images and dimensions provided with your old part before ordering.
What are common signs of a failing propeller shaft seal?
The most common sign is a leak of milky, gray, or white gear lube from the propeller area, which indicates water has mixed with the oil. You may also find fishing line wrapped around the shaft, which can damage the seal and cause it to fail.
How many seals are included in the package?
The package contents can vary. Some sellers offer a single seal, while others sell a pack of two. Please carefully read the description of the specific listing you are purchasing from to confirm the quantity.
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.