V-Belt – Fits MerCruiser 5.0L, 5.7L, 7.4L, 8.2L Engines (Replaces 57-48122Q)
V-Belt – Fits MerCruiser 5.0L, 5.7L, 7.4L, 8.2L Engines (Replaces 57-48122Q) 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
V-Belt – Fits MerCruiser 5.0L, 5.7L, 7.4L, 8.2L Engines (Replaces 5...
Product Details
This V-Belt – Fits MerCruiser 5.0L, 5.7L, 7.4L, 8.2L Engines is an essential component for the alternator and water pump drive systems on various MerCruiser V8 engines manufactured between 1988 and 2001, including Bravo and MIE models. It is specifically designed as a direct-fit replacement for older systems that use a v-belt configuration.
This belt provides a reliable aftermarket cross-reference for Mercury/Quicksilver part numbers 57-48122Q, 48122, 48122Q; Sierra 18-15480; and GLM 89440.
- Installs as an OEM replacement for alternator and water pump drives.
- Designed for marine environments and compatible with raw and fresh water cooling systems.
- This is a traditional V-belt, not a serpentine belt.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/Quicksilver | 57-48122Q |
| Mercury/Quicksilver | 48122 |
| Mercury/Quicksilver | 48122Q |
| Sierra | 18-15480 |
| GLM | 89440 |
| OMC | 0509295 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser models, this belt fits specific V8 engines from 1988–1997. Pay close attention to the notes, as some later models switched to serpentine belts.
| Model | Engine | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| 7.4L BRAVO | 454 V-8 | 1988–1991 | 57-48122Q | Alternator/water pump belt |
| 7.4L/LX BRAVO | 454 V-8 | 1992–1997 | 57-48122Q | |
| 7.4LX Bravo TBI | 454 V-8 | 1996–1997 | 57-48122Q | |
| 7.4LX Bravo MPI | 454 V-8 | 1996–1997 | 57-48122Q | |
| 7.4L MIE | 454 V-8 | 1989–1997 | 57-48122Q | |
| 454 MAG | 454 V-8 | 1988–1997 | 57-48122Q | |
| 454 MAG MPI | 454 V-8 | 1994–1997 | 57-48122Q | |
| 454 MAG Ski | 454 V-8 | 1995–1997 | 57-48122Q | |
| 502 MAG | 502 V-8 | 1990–1997 | 57-48122Q | |
| 502 MAG MPI | 502 V-8 | 1994–1997 | 57-48122Q | |
| 8.2L MIE | 502 V-8 | 1990–1997 | 57-48122Q | |
| 8.2L MPI MIE | 502 V-8 | 1996–1997 | 57-48122Q | |
| 5.7L Bravo | 350 V-8 | 1996 | 57-48122Q | For pre-1997 models with v-belt (not serpentine) |
For OMC models, this belt serves as a replacement for part number 0509295 on various V6 and V8 engines.
| Model | Engine | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| 262 King Cobra | 4.3L V-6 | 1989+ | 0509295 | |
| 350 King Cobra | 5.7L V-8 | 1988 | 0509295 | |
| 454 King Cobra | 7.4L V-8 | 1988–1990 | 0509295 | |
| 3.8L V-6 | 3.8L V-6 | 1982–1986 | 0509295 | |
| 4.3L V-6 | 4.3L V-6 | 1982–1989 | 0509295 | |
| 5.0L V-8 | 5.0L V-8 | 1982–1987 | 0509295 | |
| 5.7L V-8 | 5.7L V-8 | 1982–1990 | 0509295 |
Technical Specs
- Product Type
- Engine V-Belt
- Application
- Alternator & water pump drive
- Installation
- OEM replacement for alternator/water pump drive
- Length
- 1,219 mm (48 inches)
- Material
- Rubber with reinforced fiber core
- Type
- V-belt (not serpentine)
- Compatible Systems
- Raw water cooling, fresh water cooling
- Warranty
- 1 year (manufacturer defect)
What’s in the Box
- 1 x V-Belt (Replaces 57-48122Q/48122/48122Q/0509295)
Installation Notes
- Ensure the engine is turned off and has cooled completely.
- Disconnect the battery to prevent accidental starting.
- Loosen the alternator pivot bolt enough to allow movement. Loosen any adjuster-plate or tensioner bolts as well.
- Note the routing path around the crankshaft, water-pump, and alternator pulleys.
- Relieve tension by swiveling the alternator and remove the old belt.
- Inspect pulley grooves for wear, rust, or corrosion. Clean them if necessary.
- Route the new belt following the same path as the old one.
- Tension the new belt by carefully swiveling the alternator away from the engine.
- A correctly tensioned V-belt deflects about 1 cm (½″) under moderate thumb pressure.
- Tighten all bolts to the manufacturer's recommended torque specifications.
- Reconnect the battery, start the engine, and observe the belt to ensure it is tracking correctly.
- After a brief run, shut down the engine and recheck the belt tension.
Troubleshooting & FAQ
How do I know if this V-belt will fit my engine?
First, check the compatibility tables for MerCruiser and OMC models and years. It is critical to confirm this belt is for models using a v-belt, not a multi-groove serpentine belt. Compare the 48-inch length and part number 57-48122Q to your existing belt or service manual.
What is the correct tension for this V-belt?
A properly tensioned belt should have about 1 cm (½″) of deflection when pressed firmly with your thumb at the midpoint of its longest span. Over-tightening can damage bearings, while a loose belt will slip and may cause squealing or poor charging/cooling performance.
What are the signs of a failing V-belt?
Common signs of a worn or failing V-belt include high-pitched squealing noises (especially on startup), visible cracks or fraying on the belt's surface, a glazed or shiny appearance in the pulley grooves, and potential engine overheating or battery charging warnings.
Is this a serpentine belt?
No, this is a standard V-belt designed for the alternator and water pump drive on the specified engine models. It is not interchangeable with serpentine belts, which are wider and have multiple ribs.
How often should I replace my engine's V-belt?
While replacement intervals vary by engine use and conditions, a general best practice is to inspect V-belts annually and replace them every 3-5 years or at the first sign of wear, such as cracking, glazing, or fraying.
What is the difference between OEM and aftermarket parts?
This listing is for an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It is engineered to meet or exceed OEM-level specifications using comparable materials and is manufactured in an ISO 9002 certified facility. All parts are batch-inspected for quality and consistency.
What are your shipping speed and cost?
We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free. Expedited shipping options, where available, will be presented at checkout.
What is your warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against 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 quality control.
Payment & Security
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