2016 GMC Acadia Serpentine Belt Guide

Quick Answer: 2016 GMC Acadia Serpentine Belt Part Numbers

For the 2016 GMC Acadia, which is equipped with the 3.6L V6 (LLT) engine, here are the specifications and common part numbers for the serpentine belt and its related components.

Important Note: Always verify part numbers with your VIN at the dealership or with your parts supplier before purchasing to ensure a perfect match, as variations can exist.

• Serpentine Belt Length & Rib Count: 96.85 inches (2460 mm) | 6-Rib
• OEM Belt Part Number: GM 12636224
• Aftermarket Belt Cross-References:
  • Gates: K060968
  • Dayco: 5060968
  • Continental Elite: 4060968
• Automatic Belt Tensioner Assembly: GM 12669569
• Idler Pulley (Smooth): GM 12631742

Belt Routing

The 3.6L V6 in the 2016 Acadia uses a single serpentine belt to drive all engine accessories. Correct routing is critical for proper function and to prevent damage. Before you remove the old belt, we strongly recommend taking a clear photograph of the belt's path for reference.

The belt path is as follows:

1. Starts at the Crankshaft Pulley at the bottom center of the engine.
2. Wraps up and around the Air Conditioning (A/C) Compressor pulley.
3. Goes down and around the smooth Idler Pulley.
4. Travels up to the Alternator pulley at the top of the engine.
5. Comes down around the Power Steering Pump pulley.
6. Goes under the Water Pump pulley.
7. Finishes by wrapping around the Tensioner Pulley, which applies pressure to the system.

How to Replace the Serpentine Belt

Replacing the serpentine belt is a manageable task for a DIYer with the right tool. The key is releasing the tension from the automatic belt tensioner.

To do this, locate the belt tensioner assembly. It has a pulley that presses against the belt to keep it tight. You will see a 3/8-inch square hole in the body of the tensioner arm. Insert a long-handled 3/8" drive breaker bar or a dedicated serpentine belt tool into this square hole.

Rotate the breaker bar to move the tensioner arm and release the belt's tension. While holding the tensioner in the released position, carefully slip the old belt off one of the accessible pulleys, like the alternator. Once the belt is free, slowly release the tensioner back to its resting position. Use your photo and the routing diagram above to install the new belt, making sure the ribbed side of the belt makes contact with all ribbed pulleys and the smooth side contacts the smooth idler and tensioner pulleys. Once the belt is routed correctly on all pulleys except for one of the top, easily accessible ones (like the alternator), use your breaker bar to release the tensioner again and slip the belt over the final pulley. Visually inspect the full path to ensure it is seated correctly in every groove before starting the engine.

Replacement Interval

While there is no universally mandated replacement interval, a serpentine belt should be inspected during every oil change and at major service intervals (30,000, 60,000 miles). As a general rule of thumb, most technicians recommend replacing the serpentine belt as a preventative measure between 75,000 and 100,000 miles, or sooner if signs of wear are visible.

Signs of a Failing Belt or Tensioner

Your belt and its tensioner work together, and the failure of one can quickly damage the other. Watch for these warning signs:

• Squealing or Chirping Noises: This is the most common sign of a worn, glazed, or contaminated belt. The noise may be constant or may change with engine RPM.
• Visible Wear: Inspect the belt for cracks, fraying, missing ribs, or a shiny, glazed appearance on the underside. Any visible damage warrants immediate replacement.
• Tensioner Noise or Play: With the engine off, check the tensioner pulley. It should spin freely without a gritty feel and have no side-to-side wobble. A grinding or rumbling noise from the tensioner area when the engine is running indicates a failing bearing.
• Bouncing Tensioner Arm: When the engine is running, the tensioner arm should remain relatively steady. If you see it bouncing or vibrating excessively, the internal spring mechanism is likely worn out, and the entire assembly needs to be replaced.

Ignoring these signs can lead to the belt breaking while you're driving, which will cause an immediate loss of power steering, charging system function, and engine cooling, leaving you stranded.

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