GMC S15 Serpentine Belt: A Guide for 1987-1990 Models
Stop that annoying belt squeal and keep your S15's engine accessories running smoothly.
- First, confirm if your S15 has a single serpentine belt (late models) or multiple V-belts (early models).
- For best results, choose a premium aftermarket brand like Gates or Continental.
- Squealing is a sign of wear; inspect the belt for cracks, fraying, or glazing.
- For a complete and lasting repair, strongly consider replacing the belt tensioner and idler pulleys along with the belt.
Is it a Serpentine Belt or V-Belts?
Before buying a new belt for your GMC S15, you must know what your truck uses. The 1983-1990 model years saw a transition in belt technology.
- 1983-1986 Models: Most S15 trucks from this era, especially with the 4-cylinder or early 2.8L V6 engines, use multiple individual V-belts to run the accessories. Each component has its own belt.
- 1987-1990 Models: Later models, particularly those equipped with the 2.8L V6 and 4.3L V6 engines, use a single, wide, ribbed serpentine belt.
Signs of a Failing Serpentine Belt
A worn-out serpentine belt gives clear warning signs. Ignoring them can lead to a breakdown if the belt snaps.
- Squealing or Chirping Noises: This is the most common symptom. The noise may be constant or happen when you start the engine, turn on the A/C, or during wet weather. It's often caused by a worn, glazed, or contaminated belt.
- Visible Damage: Inspect your belt. If you see cracks, fraying, missing ribs, or glazing (a shiny, smooth surface), it's time for a replacement.
- Accessory Problems: If your battery isn't charging (dimming lights), the power steering feels heavy, or the engine starts to overheat, the belt may be slipping or broken, failing to power the alternator, power steering pump, or water pump.
Choosing the Right Aftermarket Belt
For a vehicle like the 1987-1990 S15, a quality aftermarket belt often meets or exceeds the original factory specifications. Here’s a breakdown of available brands.
Brand Quality Tiers
| Tier | Brands | Quality & Performance |
|---|---|---|
| Premium | Gates, Continental | Known for durability and quiet operation. Gates is a highly respected brand in forums and often an OEM supplier. Continental is also a top choice, known for excellent engineering. You can't go wrong with either for your S15. |
| Standard | Dayco | A well-known brand that offers a reliable product. While some users in forums report mixed experiences compared to Gates, they are a solid and widely available option that will get the job done. |
| Economy | Skyward, Store Brands | These are budget-friendly belts. They will work, but may not have the same longevity or noise-resistance as premium brands. Skyward did not appear in enthusiast forums, suggesting it is a value-oriented private label. |
Frequently Asked Questions
Why is my new serpentine belt still squeaking? 🎬 Watch this guide to diagnose and fix persistent belt squeal.
If a new belt squeaks, the belt itself is rarely the problem. The noise is likely caused by a weak tensioner, a misaligned pulley, or fluid contamination on the pulleys. Another common cause is worn bearings in an idler pulley, alternator, or power steering pump.
Is a Gates belt really better than Dayco for my S15?
Based on discussions among mechanics and truck owners, Gates generally has a stronger reputation for long-term durability and quiet operation. However, Dayco is a functional and more affordable alternative that many people use without issue. For peace of mind and potentially longer life, Gates is often the preferred choice.
Was there a recall on the S15 serpentine belt?
No. Searches of the National Highway Traffic Safety Administration (NHTSA) database show no recalls or specific technical service bulletins (TSBs) related to the serpentine belt for the 1983-1990 GMC S15.
How hard is it to replace the serpentine belt myself? 🎬 See this step-by-step walkthrough for replacing your serpentine belt.
It is a relatively easy job for a DIY mechanic. The process involves using a long-handled wrench or breaker bar on the automatic tensioner to relieve pressure, allowing you to slip the old belt off and a new one on. Be sure to draw or photograph the belt's routing path before you begin.
Helpful Videos
Technical Specifications
OEM Part Numbers: 10189266 19244944 14102643
Varies by engine and accessories (A/C, no A/C). The 4.3L V6 and 2.8L V6 use a 6-rib belt. Length is critical and must be matched to your specific vehicle configuration.
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.
- GMC S15: