Propeller Nut Kit – Fits Mercury/Mariner 30-60 HP Outboards (Replaces 11-69578Q1)
Propeller Nut Kit – Fits Mercury/Mariner 30-60 HP Outboards (Replaces 11-69578Q1) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Propeller Nut Kit – Fits Mercury/Mariner 30-60 HP Outboards (Replac...
Product Details
This Propeller Nut Kit – Fits Mercury/Mariner 30-60 HP Outboards (Replaces 11-69578Q1) provides the necessary hardware to securely fasten the propeller on compatible outboard engines. It is a crucial component for ensuring safe and efficient propeller operation, designed for durability in marine environments.
It serves as a direct interchange for Mercury/Quicksilver part number 11-69578Q1 and Sierra part 18-3702.
- Requires only standard hand tools for installation.
- Features a special locking nut and tab washer design for added security against vibration.
- Constructed from high-strength alloy steel for corrosion resistance and long service life.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/Quicksilver | 11-69578Q1 |
| Sierra | 18-3702 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury/Mariner | Outboard | 30 | 2-Stroke | 11-69578Q1 | ||
| Mercury/Mariner | Outboard | 35 | 2-Stroke | 11-69578Q1 | ||
| Mercury/Mariner | Outboard | 40 | 2-Stroke | 11-69578Q1 | ||
| Mercury/Mariner | Outboard | 45 | 2-Stroke | 11-69578Q1 | ||
| Mercury/Mariner | Outboard | 50 | 2-Stroke | 11-69578Q1 | ||
| Mercury/Mariner | Outboard | 55 | 2-Stroke | 11-69578Q1 | ||
| Mercury/Mariner | Outboard | 60 | 2-Stroke | 11-69578Q1 |
Technical Specs
- Product Type
- Propeller Nut Kit
- Installation
- Hand tools required
- Housing Material
- Alloy Steel
- Housing Color
- Silver
- Dimensions
- Length: 1.0 in, Width: 6.0 in, Height: 7.13 in
- Weight
- 0.09 kg (3.2 oz)
- Thread Type
- Unified National Coarse (UNC)
- Thread Style
- Right Hand
- Thread Coverage
- Fully Threaded
- Thread Class
- Coarse
- Other Technical Attributes
- Special locking nut design with tab washers
What’s in the Box
- 1 x Special Locking Nut (11-69578Q1)
- 2 x Tab Washers (11-69578Q1)
Installation Notes
- Ensure the engine is in neutral and the ignition is off. For safety, disconnect the battery.
- Remove the old propeller nut. This may require unbending a locking tab or removing a cotter pin first.
- Slide the propeller off the shaft, taking care to note the order of any washers or spacers.
- Clean and inspect the propeller shaft splines for any damage or excessive wear.
- Install the new hardware in the correct sequence as per your engine’s service manual. The tab washers are essential for securing the nut.
- Tighten the new propeller nut to the manufacturer-specified torque value using a torque wrench. Do not overtighten.
- Once torqued, bend the tabs of the washer securely against the flat sides of the nut to lock it in place.
Troubleshooting & FAQ
How do I know if this kit fits my engine?
This kit is designed for the specified Mercury/Mariner 30-60 HP outboard range. The most reliable way to confirm fitment is to match the OEM part number 11-69578Q1 with the part number listed in your engine's service manual.
What is the purpose of the tab washers?
The tab washers are a critical safety component. After the nut is tightened to the correct torque, one or more tabs are bent up against the flat sides of the nut. This physically prevents the nut from vibrating loose during operation, which could otherwise lead to propeller loss.
What are signs of a failing or loose prop nut?
Common symptoms include excessive vibration felt through the boat, a rattling or clunking noise from the stern (especially when shifting), and visible wobbling of the propeller. If you notice any of these signs, stop the engine immediately and inspect the propeller assembly.
When should the propeller nut and washers be replaced?
It is recommended to inspect the nut and washers for corrosion or damage whenever the propeller is removed. Tab washers are generally considered a single-use item and should be replaced each time they are unbent and removed.
Is a special tool required for installation?
While basic hand tools can be used, a calibrated torque wrench is highly recommended to ensure the nut is tightened to the correct specification. Improper torque can lead to damage or failure. You will also need pliers to bend the washer tabs.
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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