Volvo Penta Prop Nut Kit - Fits Volvo SX/Cobra Sterndrive (Replaces 3850984, 22188)
Volvo Penta Prop Nut Kit - Fits Volvo SX/Cobra Sterndrive (Replaces 3850984, 22188) 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.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Volvo Penta Prop Nut Kit - Fits Volvo SX/Cobra Sterndrive (Replaces...
Product Details
This Volvo Penta Prop Nut Kit is designed for a direct-fit replacement on Volvo Penta SX and Cobra SX sterndrives using a standard 19-spline propeller shaft. The kit provides the essential hardware needed to securely fasten your propeller.
It directly replaces OEM and aftermarket part numbers including Volvo Penta 3850984, GLM 22188, Sierra 18-3733, Mercury 802126Q1, and OMC 5008966.
- Engineered for direct-fit installation on specified sterndrive models.
- Constructed from marine-grade materials suitable for harsh marine environments.
- Includes propeller nut, keeper, and cotter pin for a complete installation.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 3850984 |
| GLM | 22188 |
| Sierra | 18-3733 |
| Mercury | 802126Q1 |
| OMC | 5008966 |
| Redline | RL3708-1 |
| Sterndrive | 98-306-45 / 98-306-45k |
| AQU | 3221 / 2671 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Volvo Penta drives, this kit fits all SX and Cobra SX models that use a 19-spline propeller shaft.
For OMC drives, this kit is compatible with Cobra models using a 19-spline shaft.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Volvo Penta | SX Drive | All | 4-Stroke | All | 3850984 | For all 19-spline shaft models |
| Volvo Penta | Cobra SX | All | 4-Stroke | All | 3850984 | For all 19-spline shaft models |
| OMC | Cobra | All | 4-Stroke | All | 5008966 | For compatible 19-spline shaft models |
Technical Specs
- Product Type
- Propeller Nut Kit
- Installation
- Direct fit for OEM applications
- Connection
- 19-spline propeller shaft
- Housing Material
- Marine grade stainless steel
- Housing Color
- Silver
- Dimensions
- 14.0" x 10.0" x 1.0"
- Fitting Type
- Nut, keeper, and cotter pin assembly
- Operating Temperature
- Marine environment
- Warranty
- 1 year (TMP Global)
- Other Technical Attributes
- Kit does not include thrust washer
What’s in the Box
- 1 x Propeller Nut
- 1 x Keeper
- 1 x Cotter Pin
Installation Notes
- Ensure the engine is off, in neutral, and the battery is disconnected before starting work.
- Remove the old cotter pin, nut keeper, and propeller nut from the propeller shaft.
- Clean and inspect the propeller shaft splines and threads for damage or wear.
- Slide the propeller onto the shaft, followed by the new keeper.
- Thread on the new propeller nut and torque it to the manufacturer's specification.
- Align the keeper with the hole in the propeller shaft and insert the new cotter pin, bending the ends to secure it.
Troubleshooting & FAQ
Will this fit my non-SX Volvo Penta or OMC drive?
This kit is specifically designed for Volvo Penta SX, Cobra SX, and compatible OMC Cobra drives with a 19-spline shaft. It is not guaranteed to fit other models. Always verify your drive model and shaft spline count before ordering.
What is the difference between this and the OEM kit?
Our aftermarket kit is manufactured to meet or exceed OEM specifications using comparable, high-quality marine-grade stainless steel. It provides the same function and durability as the original part at a better value.
Does this kit include a thrust washer?
No, this particular kit does not include the thrust washer. The washer should be inspected and replaced separately if it shows signs of wear or damage.
How often should the prop nut and cotter pin be replaced?
It is good practice to inspect the prop nut, keeper, and cotter pin every time you remove the propeller for service. The cotter pin is a single-use item and should always be replaced. The nut and keeper should be replaced if they show signs of corrosion, damage, or thread wear.
What are the signs of a failing prop nut or keeper?
Signs of failure can include visible corrosion, stripped threads on the nut, or cracks/damage to the keeper. A loose-feeling propeller or unusual vibrations during operation can also indicate an issue with the fastening hardware.
Is a special tool required for installation?
You will need a properly sized propeller wrench or socket to torque the nut to the correct specification, along with pliers to bend and secure the cotter pin. No other special tools are typically required.
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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