Gearcase Seal Kit – Fits Mercury Marine 135/150 HP EFI (Replaces 8M0057716)
Gearcase Seal Kit – Fits Mercury Marine 135/150 HP EFI (Replaces 8M0057716) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Gearcase Seal Kit – Fits Mercury Marine 135/150 HP EFI (Replaces 8M...
Product Details
This aftermarket Gearcase Seal Kit – Fits Mercury Marine 135/150 HP EFI (Replaces 8M0057716) is engineered for Mercury Marine 135/150 HP EFI 4-Stroke outboards (2011 and newer, including Sea Pro models). It provides the essential seals for a lower unit rebuild or repair, ensuring a precise fit to prevent water intrusion and oil leaks.
This kit is a direct interchange for Mercury OEM part 8M0057716 and aftermarket equivalents including XARONF 8M0057716 and DEFYAN 8M0057716.
- Designed for direct replacement installation.
- Constructed from high-quality rubber/polymer compounds for durability.
- Contains a comprehensive set of seals for servicing the gearcase.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 8M0057716 |
| XARONF | 8M0057716 |
| DEFYAN | 8M0057716 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 135 HP EFI | 135 | 4-Stroke | 2011+ (2B131942 & Up) | 8M0057716 | |
| Mercury | 150 HP EFI | 150 | 4-Stroke | 2011+ (1B905505 & Up) | 8M0057716 | |
| Mercury | 150 HP EFI Sea Pro | 150 | 4-Stroke | 2011+ (2B139139 & Up) | 8M0057716 | |
| Mercury | 7150F23ZD | 150 | 4-Stroke | 2011 | 8M0057716 | |
| Mercury | 7150F24ZD | 150 | 4-Stroke | 2011 | 8M0057716 | |
| Mercury | 7150F13ZD | 150 | 4-Stroke | 2011 | 8M0057716 |
Technical Specs
- Product Type
- Gearcase Seal Kit
- Installation
- Direct replacement
- Housing Material
- Rubber/polymer seals
- Dimensions
- 24.0 × 20.0 × 5.0 in
- Weight
- 0.29 lb (0.13 kg)
- Warranty
- 1 Year (on aftermarket versions)
What’s in the Box
- 1 x Gearcase Seal Kit (8M0057716)
Installation Notes
- Drain the gearcase oil completely into a suitable container.
- Carefully detach and remove the lower unit (gearcase) from the outboard motor.
- Disassemble the gearcase components, noting the position and orientation of each original seal.
- Thoroughly clean all sealing surfaces, removing any old sealant, gasket material, or corrosion.
- Install the new seals from the kit, applying a light coat of marine grease to aid installation and prevent damage.
- Reassemble the gearcase, ensuring all parts are correctly aligned and torqued to the manufacturer’s specifications.
- Reinstall the lower unit onto the outboard motor.
- Refill the gearcase with the recommended lower unit lubricant and inspect for leaks before operation.
Troubleshooting & FAQ
How do I know if this seal kit fits my Mercury outboard?
The best way to confirm compatibility is by matching your engine's serial number to the ranges provided in the "Engine & Model Compatibility" table. This kit fits specific Mercury 135 HP and 150 HP EFI 4-Stroke models from 2011 onward.
What are the signs of a failing gearcase seal?
The most common symptom is milky or creamy-looking gear oil drained from the lower unit, which indicates water intrusion. You might also find oil leaking from the propeller shaft area or around the drain and fill screws.
Is this a complete kit for a lower unit reseal?
This kit contains the primary seals required for servicing the gearcase as a replacement for OEM part 8M0057716. While a detailed list of every individual seal is not provided, it is designed to match the contents of the original Mercury kit.
What is the recommended replacement interval for these seals?
Seals should be replaced whenever the lower unit is serviced for other reasons (like a water pump impeller change) or immediately if signs of leaks or water intrusion are found. As a preventative measure, replacing them every few years is good practice, especially in saltwater environments.
Do I need special tools to install this kit?
Yes, professional installation is recommended. Specialized tools such as a bearing carrier puller, seal drivers, and a torque wrench are often necessary for proper disassembly and reassembly of the gearcase without damaging components.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- 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 — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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