Marine Engine V-Belt – Fits MerCruiser 3.7L-7.4L & OMC 7.5L V8 (Replaces Mercury, OMC, Sierra, Mallory)
Marine Engine V-Belt – Fits MerCruiser 3.7L-7.4L & OMC 7.5L V8 (Replaces Mercury, OMC, Sierra, Mallory) is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Marine Engine V-Belt – Fits MerCruiser 3.7L-7.4L & OMC 7.5L V8 ...
Marine Engine V-Belt – Fits MerCruiser 3.7L-7.4L & OMC 7.5L V8 (Replaces Mercury, OMC, Sierra, Mallory) is backordered and will ship as soon as it is back in stock.
Product Details
This high-performance Marine Engine V-Belt – Fits MerCruiser 3.7L-7.4L & OMC 7.5L V8 (Replaces 57-33170Q) is engineered for reliable power transmission in a range of MerCruiser (3.7L to 7.4L) and OMC (7.5L V8) marine engines manufactured between 1973 and 1995.
It serves as a direct cross-reference for multiple OEM and aftermarket parts, including Mercury 57-33170Q, OMC 0912714, Sierra 18-15520, and Mallory 9-55001.
- Installs on the engine accessory drive to power components like power steering pumps.
- Constructed with high-strength synthetic cords to resist stretching and shock-load failure.
- Specifications: 52-inch length (132.1 cm) and 29/64-inch top width (11.5 mm).
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 33170 |
| Mercury | 34359 |
| Mercury | 37619 |
| Mercury | 37619Q |
| Mercury | 57-33170Q |
| Mercury | 57-34359 |
| Mercury | 57-37619Q |
| Mercury | 57-37619T |
| OMC | 0509287 |
| OMC | 0509288 |
| OMC | 0909818 |
| OMC | 0912714 |
| Sierra | 18-15520 |
| Mallory | 9-55001 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser models, this belt fits a wide array of 4-stroke engines from the 3.7L to the 7.4L series, including 350 MAG and 320 EFI models. Please check your specific model and year range below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 3.7L | 175 | 4-Stroke | 1987 | 57-33170Q | |
| MerCruiser | 3.7L (4bbl) | 185 | 4-Stroke | 1983–1984 | 57-33170Q | |
| MerCruiser | 3.7L (2bbl) | 185 | 4-Stroke | 1985–1986 | 57-33170Q | |
| MerCruiser | 3.7L | 205 | 4-Stroke | 1985–1991 | 57-33170Q | A331455-D714369 |
| MerCruiser | 4.3L | 175/185 | 4-Stroke | 1985–1992 | 57-33170Q | A331455-D714106 |
| MerCruiser | 5.0L | 898/200 | 4-Stroke | 1985–1995 | 57-33170Q | 6218462-F600999 |
| MerCruiser | 5.0L | 228/230 | 4-Stroke | 1983–1995 | 57-33170Q | 6218462-F600999 |
| MerCruiser | 5.0L MIE | 228/230 | 4-Stroke | 1978–1987 | 57-33170Q | 4929030-B788151 |
| MerCruiser | 5.7L | 260 | 4-Stroke | 1983–1995 | 57-33170Q | 6218462-F600999 |
| MerCruiser | 7.4L | 225 | 4-Stroke | 1973–1974 | 57-33170Q | 3385721-4166999 |
| MerCruiser | 350 MAG | - | 4-Stroke | 1986–1995 | 57-33170Q | A635178-F600999 |
| MerCruiser | 320 EFI | - | 4-Stroke | 1987–1989 | 57-33170Q | A543604-C622418 |
This belt is compatible with OMC 7.5L V8 460 engines, including the King Cobra model from 1987–1988.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| OMC | 7.5L V8 460 | - | 4-Stroke | 1987 | 0912714 | WP&DH PS |
| OMC | 7.5L V8 460 King Cobra | - | 4-Stroke | 1988 | 0912714 | WP&DH PS |
Technical Specs
- Product Type
- V-Belt
- Installation
- Engine Accessory Drive
- Length
- 52 inches (132.1 cm)
- Top Width
- 29/64 inch (11.5 mm)
- Housing Material
- Synthetic rubber with high-strength cords
- Other Technical Attributes
- Power steering belt; High strength synthetic cords resist shockload failure
What’s in the Box
- 1 x V-Belt (57-33170Q)
Installation Notes
- Ensure the engine is off and cool, and disconnect the battery terminals for safety.
- Locate the v-belt routing diagram, usually found on a decal in the engine bay or in your service manual.
- Identify the belt tensioner pulley. Using the appropriate tool, release the tension on the belt.
- Carefully slide the old belt off the pulleys. Note its path if you do not have a diagram.
- Route the new belt onto the pulleys following the correct path. Ensure it is properly seated in all grooves.
- Re-apply tension to the belt using the tensioner. Check for proper tension (typically about half an inch of flex).
- Reconnect the battery, start the engine, and listen for abnormal noises. Visually confirm the belt is tracking correctly.
Troubleshooting & FAQ
How do I find the right V-belt for my marine engine?
Always start by consulting your engine's service manual for the correct OEM part number. You can then use our Part Number Matrix to see if this belt is a listed cross-reference. Also, confirm your engine model and year are included in the compatibility tables above.
What are the signs of a worn or failing V-belt?
Common symptoms include a loud squealing or chirping sound from the engine, visible cracks, glazing (shiny spots), or fraying on the belt's surface. You may also notice decreased performance from accessories like the alternator or power steering pump.
How often should I replace my engine's V-belt?
There is no single interval that fits all engines and conditions. A good rule of thumb is to inspect belts annually for wear and plan for replacement every 3-5 years or as recommended in your owner's manual. Harsh marine environments can accelerate wear.
Is this belt used for the alternator, power steering, or water pump?
This v-belt is primarily listed as a power steering belt for many of the compatible models. However, its exact function can vary. Always refer to a belt routing diagram for your specific engine to confirm its application.
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
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
