Accessory Drive V-Belts for the 1966 GMC 1500
Understand the multiple V-belt system on your classic GMC to keep its accessories running strong.
- Your 1966 GMC 1500 uses multiple individual V-belts, not a single serpentine belt.
- Squealing noises and visible cracks are the most common signs that a belt needs replacement.
- Aftermarket brands like Gates and Dayco are the reliable, standard choice for these classic trucks.
- Proper belt tension after installation is critical to prevent slipping and ensure a long service life.
Your 1966 GMC 1500's V-Belt System
It's important to know that the term 'Accessory Drive Belt' on a classic truck like your '66 GMC 1500 refers to a set of individual V-belts, not a single, wide serpentine belt found on newer vehicles. Your truck has separate belts for different accessories. This means you might have a belt for the alternator, another for the power steering pump, and another for the fan and water pump. When one belt shows wear, it's good practice to inspect them all.
Signs of a Failing V-Belt
A bad V-belt will usually give you a few warning signs before it fails completely. Ignoring these can lead to a breakdown.
- Squealing Noises: This is the most common symptom, especially noticeable when you start the engine or during acceleration. It's caused by the belt slipping on the pulleys.
- Visible Damage: Regularly inspect your belts. Look for cracks, fraying, glazing (a shiny, hardened surface), or pieces missing. Any visible damage means the belt needs to be replaced soon.
- Accessory Failure: If your battery isn't charging (dimming headlights, battery light on), the alternator belt may have failed. If the engine starts to overheat, the water pump belt could be the problem. Loss of power steering is another sign of a failed belt.
Choosing the Right Aftermarket Belts
For a vintage vehicle like a 1966 GMC, finding new original equipment (OEM) parts is nearly impossible. The good news is that high-quality aftermarket brands are the go-to standard and offer excellent performance, often exceeding the specifications of the original 1960s belts.
You have two solid brand choices available:
- Gates: Often considered a top-tier brand, Gates is a well-respected manufacturer and is even the original supplier for many car companies. Forum users and mechanics frequently recommend Gates for reliability and longevity.
- Dayco: Dayco is another long-standing, reputable brand that produces quality belts. They are a major supplier to both aftermarket and original equipment manufacturers and are known for making durable products.
You can't go wrong with either Gates or Dayco. Both make excellent V-belts that will perform well on your classic GMC. The most important factor is ensuring you buy the correct length and width for each specific accessory drive.
| Part Type | Price Range (Per Belt) |
|---|---|
| New Aftermarket (Dayco, Gates) | $22.65 - $34.01 |
| New OEM | Not Available |
| Shop Labor | $40 - $150 |
Note: Your truck has multiple belts. The total parts cost will depend on how many belts you choose to replace at once. Labor costs can vary by location and shop.
Frequently Asked Questions
How many belts does my 1966 GMC 1500 have?
The exact number of belts depends on the engine and options your truck came with (like power steering). Most will have between two and four separate V-belts to run the alternator, water pump/fan, and power steering pump. You'll need to visually inspect your engine to confirm the configuration.
Can I replace just one bad belt?
Yes, you can replace only the belt that has failed. However, if one belt is old and worn, the others are likely not far behind. It's good practice and often more time-efficient to replace all the belts at the same time.
How do I know if the new belt is tight enough?
Improper tension is a primary cause of belt squeal and premature failure. A general rule of thumb for V-belts is that at the midpoint of its longest span, you should be able to press it down about half an inch with your thumb. It should feel snug, not loose, but not guitar-string tight.
Are there any recalls for my truck's belts?
No, there are no recalls or technical service bulletins (TSBs) from the NHTSA related to the accessory drive belts for the 1966 GMC 1500. This is common for vehicles of this age.
Technical Specifications
Multiple V-belts of varying lengths and widths depending on engine accessories (alternator, power steering, fan/water pump).
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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.