Engine Coupler – Fits Volvo Penta 7.4L & 8.2L Engines (Replaces 3853962)
Engine Coupler – Fits Volvo Penta 7.4L & 8.2L Engines (Replaces 3853962) 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
Product Details
This aftermarket Engine Coupler – Fits Volvo Penta 7.4L & 8.2L Engines (Replaces 3853962) connects the engine's flywheel to the sterndrive driveshaft. It is designed for specific Volvo Penta 7.4L (1990–1998) and 8.2L (1992–1993, 1998) engines, as well as several OMC models from 1986–1990, including 2.5L, 3.0L, 4.3L, 5.0L, and 5.7L variants.
It serves as a direct replacement for Volvo 3853962; OMC 986338 and 983902; Sierra 18-21751; and NEXDYNAMI 3853962.
- Engineered for GM large crank diameter applications.
- Features a standard 6-bolt mounting pattern for direct fitment to the flywheel.
- Constructed from durable rubber and metal to absorb vibration and shock.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 3853962 |
| OMC | 986338 |
| OMC | 983902 |
| Sierra | 18-21751 |
| NEXDYNAMI | 3853962 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Volvo Penta applications, this part fits 7.4L and 8.2L engines within the specified year ranges.
For OMC applications, this part fits several engine displacements from 1986 to 1990. Note the "KW & KWB suffix only" requirement for 4.3L, 5.0L, and 5.7L models.
| Brand | Model | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| Volvo Penta | 7.4L | 1990–1998 | 3853962 | |
| Volvo Penta | 8.2L | 1992–1993, 1998 | 3853962 | |
| OMC | 2.5L | 1986 | 3853962/986338/983902 | |
| OMC | 3.0L | 1986–1990 | 3853962/986338/983902 | |
| OMC | 4.3L | 1986 | 3853962/986338/983902 | KW & KWB suffix only |
| OMC | 5.0L | 1986 | 3853962/986338/983902 | KW & KWB suffix only |
| OMC | 5.7L | 1986 | 3853962/986338/983902 | KW & KWB suffix only |
Technical Specs
- Product Type
- Engine Coupler
- Installation
- Bolt mounting, approximately 3.5" center-to-center
- Fuel Type
- Gasoline
- Connection
- 6 bolt holes
- Housing Material
- Rubber with metal components
- Housing Color
- Black
- Dimensions
- 7.0" H x 6.25" W x 6.5" L
- Weight
- 6.44 lbs (2.92 kg)
- Fitting Type
- Direct mount to engine flywheel
- Other Technical Attributes
- For GM large crank diameter applications
- Warranty
- Limited Lifetime (Sierra aftermarket version)
What’s in the Box
- 1 x Engine Coupler Assembly
Installation Notes
- Disconnect the boat's battery and ensure the engine is off and cool.
- Remove the engine cover or any components obstructing access to the bell housing and drive shaft.
- Carefully unbolt and separate the outdrive from the transom assembly to access the coupler.
- Unbolt the old engine coupler from the engine's flywheel. Note the orientation of the existing hardware.
- Thoroughly clean the flywheel mounting surface to ensure a flush fit for the new coupler.
- Mount the new engine coupler onto the flywheel, aligning the bolt holes correctly.
- Install the mounting bolts and torque them to the manufacturer's recommended specifications in a star pattern.
- Reinstall the outdrive, ensuring the driveshaft splines are properly lubricated and engaged with the coupler.
- Reassemble all previously removed components and reconnect the battery.
Troubleshooting & FAQ
How do I know if this coupler is the right one for my engine?
The most reliable method is to match your existing part number to one of the direct replacement numbers listed (e.g., Volvo 3853962). Additionally, check your engine model and year against the compatibility table. For OMC models, pay close attention to the "KW & KWB suffix only" note for 4.3L, 5.0L, and 5.7L engines.
What are common signs of a failing engine coupler?
Symptoms of a worn or failed coupler include excessive vibration, especially when shifting gears or accelerating; a "clunking" or "thudding" noise from the engine bay/transom area; and a noticeable loss of power transfer to the outdrive. In severe cases, the boat may not move at all as the splined connection is completely stripped.
What does "for GM large crank diameter applications" mean?
This indicates the coupler is specifically designed to fit engine flywheels with a larger-than-standard crankshaft bolt pattern, which is common on certain General Motors (GM) based marine engines like the 7.4L and 8.2L Big Blocks.
How often should an engine coupler be replaced?
There is no fixed replacement interval; it depends on usage, engine alignment, and operating conditions. It should be inspected for signs of wear, such as cracking rubber or elongated splines, during routine outdrive service (typically every 1-2 years or 100-200 hours). Replace it if any damage is found to prevent catastrophic failure.
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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