Crankshaft Bearing Kit – Fits MerCruiser 454 (7.4L) V8 Engines
Crankshaft Bearing Kit – Fits MerCruiser 454 (7.4L) V8 Engines 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 Crankshaft Bearing Kit is engineered for MerCruiser/General Motors 7.4L (454 cu in) V8 engines, including MKIV, Gen V, and Gen VI models manufactured between 1977 and the early 2000s. It serves as a direct-fit replacement for the main bearings, crucial for restoring engine performance and reliability.
It directly interchanges with MerCruiser part numbers 23-818473, 23-818473001, 818473, and 85721, as well as FelPro 13020 and Marine Power MP0003-009, ensuring broad compatibility for engine rebuilds and repairs.
- Designed for internal engine assembly.
- Constructed from steel with a babbitt or aluminum overlay for durability.
- Includes standard size (STD) main bearings for a factory-spec fit.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 23-818473 |
| MerCruiser | 23-818473001 |
| MerCruiser | 23-8M0030217 |
| MerCruiser | 818473 |
| MerCruiser | 818473001 |
| MerCruiser | 85721 |
| MerCruiser | 85686 |
| MerCruiser | 827651T |
| Marine Power | MP0003-009 |
| FelPro | 13020 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser and General Motors engines, this kit fits a wide range of 7.4L V8 models from different generations.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| MerCruiser | 7.4L (454 cu in) MKIV | 330-340 | 4-Stroke | 1977–1989 | 23-818473 |
| MerCruiser | 7.4L (454 cu in) Gen V | 330-385 | 4-Stroke | 1989–1996 | 23-818473001 |
| MerCruiser | 7.4L (454 cu in) Gen VI | 310-385 | 4-Stroke | 1996–2000s | 23-8M0030217 |
| MerCruiser | 454 MAG | 330-385 | 4-Stroke | 1988–2000s | 818473001 |
| MerCruiser | 454 King Cobra | 330-385 | 4-Stroke | 1988–1996 | 818473001 |
| MerCruiser | 7.4L MIE | 310-330 | 4-Stroke | 1983–2000s | 818473001 |
| MerCruiser | 7.4L Bravo | 310-385 | 4-Stroke | 1988–2000s | 818473001 |
Technical Specs
- Product Type
- Crankshaft Main Bearing Kit
- Installation
- Internal engine assembly
- Fuel Type
- Gasoline
- Housing Material
- Steel with babbitt or aluminum overlay
- Bearing Size
- Standard (STD)
- Dimensions
- 6.75" L x 5.25" H x 2.25" W
- Weight
- 0.75 kg (1.65 lbs)
- Warranty
- Typically 1 year (varies by supplier)
What’s in the Box
- 1 x Crankshaft Main Bearing Kit (Replaces 818473001)
Installation Notes
- Ensure the engine block is completely disassembled, cleaned, and inspected for any damage or warping before starting.
- Carefully place each bearing shell into its corresponding location in the block and main caps, ensuring the locking tangs are correctly seated.
- Gently lay the crankshaft onto the main bearings. Place a strip of Plastigauge on each journal before installing the main caps.
- Torque the main cap bolts to the manufacturer's specified sequence and values.
- Remove the main caps to measure the compressed Plastigauge and verify oil clearances are within the engine's service manual specifications.
- If clearances are correct, thoroughly lubricate all bearing surfaces and journals with a high-quality engine assembly lube.
- Reinstall the main caps and torque them to their final specification, following the correct pattern. Ensure the crankshaft rotates smoothly by hand.
Troubleshooting & FAQ
How do I confirm this kit fits my specific 7.4L engine?
This kit is designed for MerCruiser/GM 454 (7.4L) V8 engines from 1977-2000s. The best way to confirm fitment is to match your engine's OEM bearing part number to one of the numbers listed in our Part Number Matrix. Also, check the Engine Compatibility table for your specific model and year range.
What are the signs of failing crankshaft bearings?
Common symptoms include a deep, rhythmic knocking or rumbling sound from the bottom of the engine (rod knock), low oil pressure readings, and the presence of metallic shavings in the engine oil upon inspection.
Is this a standard size (STD) or an oversized kit?
This is a standard size (STD) bearing kit. It is intended for use with crankshafts that have not been machined or ground down. If your crankshaft has been resurfaced, you will likely need oversized bearings.
What is required for a successful installation?
Installation is a complex task that requires engine disassembly. You will need a torque wrench, Plastigauge for checking clearances, engine assembly lubricant, and the engine's service manual for exact torque specifications and sequences. Professional installation is highly recommended.
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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