Propeller Shaft Oil Seal – Fits Mercury Outboard 30–150 HP (Replaces 26-70081, 26-8M0205729)
Propeller Shaft Oil Seal – Fits Mercury Outboard 30–150 HP (Replaces 26-70081, 26-8M0205729) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Propeller Shaft Oil Seal – Fits Mercury Outboard 30–150 HP (Replace...
Propeller Shaft Oil Seal – Fits Mercury Outboard 30–150 HP (Replaces 26-70081, 26-8M0205729) is backordered and will ship as soon as it is back in stock.
Product Details
This high-quality Propeller Shaft Oil Seal is designed for the lower-unit gear housing of select Mercury, Mariner, Force, and Honda outboard engines. It is listed as a replacement for applications ranging from 30 HP to 150 HP, including select 2-stroke and 4-stroke models and Honda BF75 and BF90 engines from 1997–1998.
This aftermarket replacement is cross-referenced with Mercury 26-70081 and 26-8M0205729, Honda 91255-ZW1-003, Sierra 18-2053, GLM 85530, and Mallory 9-76115. Always compare the part number, dimensions, engine model, year, and serial-number conditions with your original component before ordering.
- Installs in the lower-unit gear housing to seal the propeller shaft.
- Made from durable nitrile rubber for oil and marine-service applications.
- Dual-lip construction provides primary sealing and dust protection.
Part Number Matrix
The references below are provided to help compare OEM and aftermarket listings. Confirm the application and dimensions before installation.
| Brand | Part Number |
|---|---|
| Mercury Marine | 26-70081 |
| Mercury Marine | 26-8M0205729 |
| Honda Marine | 91255-ZW1-003 |
| Force/US Marine | 26-70081 |
| Sierra | 18-2053 |
| GLM | 85530 |
| Mallory | 9-76115 |
Engine & Model Compatibility
The following applications are associated with the listed replacement references. Model, year, stroke, gear-ratio, and serial-number conditions can affect fitment. Confirm your exact engine identification and compare the original seal before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | V-150/V-1500 | 150 | 2-Stroke | 1978–1985 | 26-70081 | V-6 series, including XR-2, Marathon, Magnum, and Work models |
| Mercury | Pro XS | 115 | 2-Stroke | 26-70081 | 3-cylinder, 1.5 L applications | |
| Mercury/Mariner | 4-Stroke EFI | 115 | 4-Stroke | 26-70081 | 2.07:1 and 2.33:1 gear ratios | |
| Mercury/Mariner | 4-Stroke EFI | 75–100 | 4-Stroke | 26-70081 | Multiple gear-ratio applications | |
| Mercury/Mariner | DFI | 75–125 | 2-Stroke | 26-70081 | 3-cylinder, 1.5 L applications | |
| Mercury/Mariner | 3-Cylinder | 70–90 | 2-Stroke | 26-70081 | Includes select Jet models | |
| Mercury/Mariner | 4-Cylinder | 75–125 | 2-Stroke | 26-70081 | Includes select 80 Jet models | |
| Mercury | Bigfoot | 40–60 | 4-Stroke | 26-70081 | 3-cylinder and 4-cylinder models | |
| Mercury/Mariner | Standard | 50–60 | 2-Stroke | 26-70081 | Includes select Jet 40–45 variants | |
| Mercury | Merc | 80–115 | 2-Stroke | 26-70081 | Gear housing and propeller-shaft applications | |
| Force | Standard | 90 | 2-Stroke | 1995–1999 | 26-70081 | Multiple clutch-type applications |
| Force | Standard | 120 | 2-Stroke | 1995–1999 | 26-70081 | Multiple clutch-type applications |
| Force | Standard | 75 | 2-Stroke | 1999 | 26-70081 | |
| Honda | BF75AT | 75 | 4-Stroke | 1997–1998 | 91255-ZW1-003 | LHTA, LRTA, and XRTA variants |
| Honda | BF90AT | 90 | 4-Stroke | 1997–1998 | 91255-ZW1-003 | LHTA, LRTA, and XRTA variants |
Technical Specs
- Product Type
- Propeller Shaft Oil Seal
- Installation Location
- Lower unit / gear housing
- Material
- Nitrile rubber
- Dimensions
- OD: 45 mm (1.76 in), ID: 30 mm (1.185 in), width: 9.1 mm (0.35 in)
- Temperature Range
- -30°C to 120°C (-22°F to 248°F)
- Construction
- Dual-lip design with primary sealing and dust protection
- Features
- Resistant to saltwater, oil, and elevated operating temperatures
What’s in the Box
- 1 × Propeller Shaft Oil Seal
- Replacement reference: Mercury 26-70081 / 26-8M0205729
This listing is for one individual oil seal. Confirm whether your gearcase requires more than one seal before beginning service.
Installation Notes
- Secure the outboard on an engine stand or tilt the lower unit upward. Place a drain pan beneath the gearcase.
- Remove the lower-unit drain and vent screws and allow the gear lubricant to drain completely.
- Remove the propeller nut and slide the propeller, thrust washer, and spacers from the shaft.
- Unbolt and carefully remove the bearing-carrier assembly from the gearcase. The propeller shaft may come out with the carrier.
- Use a seal puller or suitable flat tool to remove the old seal from the bearing carrier. Avoid scratching the metal housing.
- Clean the seal bore and surrounding area to remove old sealant, lubricant, and corrosion.
- Apply a light coat of suitable marine grease to the seal's outside edge and the housing bore if required by the service procedure.
- Using a seal driver or socket with a matching outside diameter, press the new seal squarely into position. Install it in the same orientation as the original seal; the sealing lip generally faces the fluid being contained.
- Lubricate the sealing lip and reinstall the propeller shaft and bearing-carrier assembly.
- Reinstall the propeller and hardware, then refill the lower unit with the correct marine gear lubricant according to the engine service manual.
Troubleshooting & FAQ
How do I confirm this seal will fit my specific engine?
Check your engine brand, model, horsepower, year, stroke, and serial-number range against the applicable service information. Then compare the listed dimensions—45 mm outside diameter, 30 mm inside diameter, and 9.1 mm width—with the original seal. Do not order if the dimensions, profile, or application conditions differ.
What are the signs of a failing propeller-shaft seal?
Common signs include gear lubricant leaking near the propeller area or milky, gray, or contaminated lubricant draining from the lower unit. Water contamination should be addressed promptly to help prevent damage to gears and bearings.
When should this seal be replaced?
Inspect the seal during lower-unit service and replace it whenever leakage, hardening, cracking, or damage is found. Follow the maintenance schedule and inspection procedure in your engine's service manual.
Does this listing include one seal or two?
This listing includes one propeller shaft oil seal. Some gearcase designs use more than one seal or a back-to-back seal arrangement, so verify the required quantity and installation configuration in the applicable service manual before ordering.
Is this an OEM part?
This listing is for an aftermarket replacement, not an OEM component. The OEM and aftermarket numbers shown above are reference numbers used to help identify potential applications; confirm fitment before installation.
Shipping speed and cost?
We ship worldwide quickly. Typical transit is 5–15 days. Standard shipping is free, and expedited options appear at checkout where available.
Warranty and returns?
This product is covered by a 1-year warranty against manufacturing defects under normal use. Returns are accepted within the standard return period when the item is unused and in its original condition. Contact support with your order details for assistance.
Safety & Important Information
- Verify the original part number, dimensions, engine model, year, stroke, and serial-number conditions before ordering.
- Compare the product with your original seal before installation. Do not install a part that differs in size or profile.
- This is an aftermarket replacement, not an OEM component.
- Follow the engine manufacturer's service procedures, and use professional installation when required.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered for reliable service in demanding operating conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or quality control.
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