Propeller Shaft Oil Seal – Fits Mercury Marine 30–150 HP Outboards (Replaces 26-70081, 8M0205729)
Propeller Shaft Oil Seal – Fits Mercury Marine 30–150 HP Outboards (Replaces 26-70081, 8M0205729) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Propeller Shaft Oil Seal – Fits Mercury Marine 30–150 HP Outboards ...
Propeller Shaft Oil Seal – Fits Mercury Marine 30–150 HP Outboards (Replaces 26-70081, 8M0205729) is backordered and will ship as soon as it is back in stock.
Product Details
This replacement Propeller Shaft Oil Seal is intended for selected Mercury Marine 30–150 HP outboards. It installs in the lower-unit gear housing around the propeller shaft to help retain gear lubricant and limit water intrusion. Always verify the engine model, year, serial number, and original seal dimensions before ordering.
This aftermarket replacement corresponds to Mercury Marine part numbers 26-70081 and 8M0205729. Part-number references should be used together with the engine model and serial number because fitment can vary between gearcase applications.
- Propeller-shaft oil seal for selected Mercury Marine outboards.
- External lower-unit gear-housing installation.
- Rubber seal with a metal case and spring-loaded sealing lip.
- Press-fit design for installation in the applicable seal bore.
Part Number References
Use the following manufacturer references when comparing your existing part and service-manual information.
| Brand | Part Number | Reference |
|---|---|---|
| Mercury Marine | 26-70081 | Replacement reference |
| Mercury Marine | 8M0205729 | Replacement reference |
Engine Compatibility
This seal is listed for selected Mercury Marine 30–150 HP outboards. The horsepower range alone does not confirm fitment: the same rated horsepower may use different gearcase or propeller-shaft seal applications. Check the complete engine model, production year, serial-number range, gearcase, and the dimensions of the removed seal before installation.
| Brand | Rated Horsepower | Stroke | Model / Serial Requirement | Reference Part Numbers |
|---|---|---|---|---|
| Mercury Marine | 30–150 HP | Verify for the specific engine | Confirm exact model, year, serial number, and gearcase before ordering | 26-70081; 8M0205729 |
Technical Specifications
- Product Type
- Propeller Shaft Oil Seal
- Application
- Selected Mercury Marine outboard lower units
- Installation Location
- External lower-unit gear housing
- Fitting Type
- Press-fit
- Construction
- Rubber sealing element with metal case
- Seal Design
- Spring-loaded lip seal
- Color
- Black
- Listed Dimensions
- Outer diameter: 45.0 mm (1.754 in); inner diameter: 30.0 mm (1.185 in); width: 9.1 mm (0.360 in)
What’s in the Box
- 1 × Propeller Shaft Oil Seal
Installation Notes
- Place a drain pan under the lower unit and drain the gear lubricant according to the engine service procedure.
- Remove the propeller and the related hardware from the propeller shaft.
- Remove the applicable bearing-carrier or gear-housing component that contains the seal, following the manufacturer’s service instructions.
- Extract the old seal without damaging the seal bore, shaft, or surrounding housing.
- Clean and inspect the seal bore and propeller shaft for corrosion, scoring, or wear.
- Use a suitable seal driver or correctly sized socket to press the new seal evenly into the applicable bore. Do not strike the sealing lip or shaft surface.
- Apply a light coat of suitable marine grease to the inner sealing lip if specified by the service procedure.
- Reinstall the bearing carrier, propeller, and associated hardware using the manufacturer’s torque specifications.
- Refill the gearcase with the specified gear lubricant and check for leaks and water intrusion.
Installation should be performed by a qualified marine technician when the applicable service procedure requires specialized tools or gearcase disassembly.
Troubleshooting & FAQ
How can I confirm this seal fits my engine?
Compare the complete Mercury engine model, year, serial number, and gearcase information with the applicable service-manual parts listing. Also compare the removed seal’s dimensions with the listed dimensions. The 30–150 HP range is a guide and is not, by itself, a complete fitment confirmation.
What are the signs of a failing propeller-shaft seal?
Common signs include gear lubricant around the propeller-shaft area, recurring lubricant loss, or milky lubricant caused by water contamination. Inspect the shaft and housing as well as the seal, because shaft wear or a damaged seal bore can also cause leakage.
Is this an OEM part?
No. This listing is for an aftermarket replacement propeller-shaft oil seal that references Mercury Marine part numbers 26-70081 and 8M0205729 for comparison.
Can I use the horsepower range alone to order this seal?
No. Confirm the exact model, year, serial-number range, gearcase, and seal dimensions before purchase. Outboards with the same rated horsepower can use different lower-unit components.
When should the seal be replaced?
Replace it when leakage or water intrusion is found, or whenever the applicable lower-unit service procedure requires removal of the seal. Inspect the propeller shaft and seal bore before installing a replacement.
Safety & Important Information
- Verify the model, year, serial number, gearcase, part-number reference, and dimensions before ordering.
- Do not install a seal that differs from the original application or does not match the required dimensions.
- This is an aftermarket replacement, not an OEM Mercury Marine component.
- Follow the engine manufacturer’s service manual for disassembly, seal orientation, torque values, and gear-lubricant specifications.
About Sea Sierra
- Marine Replacement Parts — Parts selected for common service and repair applications.
- Application-Focused Information — Compare engine identification details and original-part dimensions before installation.
- Support for Maintenance Work — Use the applicable manufacturer service procedure for safe, accurate installation.
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