Accessory Drive Belt Guide for the 2003-2008 INFINITI FX45
Understand the two-belt system on your FX45's V8 and how to choose the right replacement parts.
- The 2003-2008 FX45 uses two separate belts; one for the main accessories and one for power steering.
- If the main belt breaks, pull over immediately to prevent engine damage from overheating.
- For a complete and reliable repair, replace both belts, the tensioners, and the idler pulleys at the same time.
- High-quality aftermarket brands like Bando and Mitsuboshi are often the OEM supplier and offer the same quality as dealer parts for less money.
Is Your FX45 Drive Belt Failing?
The drive belts on your FX45's VK45DE engine are constantly exposed to heat and tension, causing them to wear out over time. Ignoring the warning signs can lead to a sudden breakdown and potential engine damage. Watch for these common symptoms.
Symptoms of a Bad Accessory Drive Belt
- Squealing Noises: A high-pitched squeal or chirp from the engine bay is the most common sign. This noise may be worse on cold starts, when turning the steering wheel, or when switching on the A/C. It indicates the belt is slipping.
- Visible Wear and Tear: Pop the hood and inspect the belts. Look for cracks, fraying, missing ribs, or a glazed, shiny appearance on the belt's surface. Any visible damage means it's time for a replacement.
- Accessory Problems: If you notice dimming headlights or a battery warning light, the main belt may be slipping on the alternator. If your steering becomes suddenly heavy, the dedicated power steering belt has likely failed.
- Engine Overheating: This is a critical symptom. The main serpentine belt drives the water pump. If this belt fails, the engine will quickly overheat, which can cause severe and expensive damage.
Known Issues: Tensioners and Pulleys
While there are no official recalls for the belt system on the FX45, the automatic belt tensioners and idler pulleys are common failure points. The bearings inside these parts can wear out, causing grinding or squealing noises that are often mistaken for a bad belt. A failing tensioner can't hold proper tension, which will destroy a new belt quickly. For a lasting repair, it is highly recommended to replace the tensioners and idler pulleys at the same time as the belts.
Choosing the Right Aftermarket Belts: OEM vs. Aftermarket
For many Japanese vehicles, including your INFINITI, the original factory belts are often made by companies like Bando or Mitsuboshi. When you buy an aftermarket belt from one of these brands, you are often getting the exact same quality as the OEM part without the dealership markup.
- Bando: A well-regarded brand that is a known OEM supplier for many Japanese automakers. Aftermarket Bando belts are considered a top-tier choice and offer excellent performance and longevity.
- Mitsuboshi: Another OEM supplier for brands like Honda and likely Nissan/INFINITI. Mitsuboshi belts are known for their high quality and durability, making them an excellent alternative to the dealer part.
Pro Tip: Your FX45 has two belts. You will need to order both the main serpentine belt (for alternator/water pump/AC) and the separate power steering belt for a complete job. Always verify part numbers before ordering.
Cost of Replacing INFINITI FX45 Accessory Belts (2003-2008)
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket Belts (Both) | $17 - $47 |
| New OEM Belts (Both) | $175 - $250 |
| Shop Labor | $61 - $90 |
| Total Aftermarket Replacement (Estimated) | $78 - $137 |
| Total OEM Replacement (Estimated) | $236 - $340 |
Note: Costs are estimates and do not include taxes, fees, or the recommended replacement of tensioners and pulleys.
Frequently Asked Questions (FAQ)
Do I have to replace both belts at the same time?
It is highly recommended. Both belts have been exposed to the same heat and wear over the same number of miles. Replacing them together saves you from having to do the job twice and ensures the entire accessory drive system is reliable.
Are there any recalls on the FX45 drive belts?
No. Searches of the National Highway Traffic Safety Administration (NHTSA) database show no recalls specifically for the accessory drive belts or their components on the 2003-2008 INFINITI FX45. Recalls found for this vehicle are primarily for the Takata airbag inflators.
Can I replace the FX45 drive belts myself?
Yes, this is a DIY-feasible job for someone with basic mechanical skills and tools. The VK45DE engine uses automatic belt tensioners that are released with a 14mm wrench or socket to create slack for belt removal. You will need to safely raise the front of the vehicle to access the lower splash shield and tensioners.
What happens if my main drive belt breaks while driving?
If the main serpentine belt breaks, you will immediately lose power to the alternator, water pump, and A/C. The steering will not be affected as it runs on a separate belt. The most critical issue is the water pump failure, which will cause the engine to overheat very quickly. You should pull over immediately and safely shut off the engine to prevent catastrophic damage.
Technical Specifications
OEM Part Numbers: 11720-AR010 (Main Serpentine Belt) 11950-AR00A (Power Steering Belt)
System Type: Dual belt system with automatic tensioners. Main Belt: 6-rib serpentine belt. Power Steering Belt: 4-rib v-ribbed belt.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI FX45: