2017 GMC Acadia Serpentine Belt Routing & Replacement Guide

As an ASE-certified master technician, I’ve seen my fair share of worn belts and squealing tensioners. The 2017 GMC Acadia is a fantastic family hauler, but just like any other vehicle, its serpentine belt drive system is a wear item that requires regular maintenance. Whether your Acadia is equipped with the 2.5L inline-4 or the popular 3.6L V6 engine, getting the belt routing right and using quality replacement parts is essential for keeping your alternator charging, your A/C blowing cold, and your water pump circulating coolant.

Below is your comprehensive reference guide for the 2017 GMC Acadia (focusing on the 3.6L V6 engine) serpentine belt drive system.

Quick answer

Here are the vital specifications and part numbers you need before diving into this job on the 3.6L V6 Acadia:

• Rib Count: 6-rib
• Belt Length: 65.0 inches (1651 mm)
• OEM Belt Part Number: GM/ACDelco 12693226
• Aftermarket Cross-References: Gates K060650, Dayco 5060650, Continental Elite 4060650
• Auto-Tensioner Part Number: ACDelco 12658273 (Aftermarket: Gates 39377)
• Idler Pulley Part Number: ACDelco 12658274 (Aftermarket: Gates 36322)

Note: If you have the 2.5L I4 engine, your belt length and part numbers will differ (typically a shorter belt, e.g., Gates K060415). Always verify your specific engine size with your parts supplier before purchasing.

Belt routing

Since we cannot render an image here, understanding the text-based routing path is crucial. Pro-tip: Before you put a wrench on the tensioner, use your smartphone to take a few clear photos of the existing belt routing. It takes five seconds and can save you an hour of frustration.

For the 2017 GMC Acadia 3.6L V6, the ribbed side of the belt will ride on the grooved pulleys, while the smooth back of the belt rides on the smooth pulleys (like the idler and water pump). The standard routing path follows this order:

1. Start by looping the belt down around the Crankshaft pulley (the large pulley at the bottom of the engine).
2. Bring it up and around the A/C compressor.
3. Route the smooth back of the belt under the smooth Idler pulley.
4. Pull it up and over the Alternator.
5. Route it down to the Power steering (if equipped/applicable to your specific trim's accessory drive).
6. Pass the smooth back of the belt over the Water pump.
7. Finally, slip the belt onto the Auto-tensioner while you have the tension relieved.

How to replace the serpentine belt

Replacing the belt on the 2017 Acadia can be done in your driveway with basic hand tools.

Tools required:

• Serpentine belt tool or a long 3/8" drive breaker bar
• Safety glasses and gloves

Step-by-step instructions:

1. Locate the tensioner: The automatic belt tensioner is located on the passenger side of the engine bay.
2. Relieve the tension: Insert your 3/8" breaker bar or serpentine belt tool into the square drive hole on the tensioner arm. Rotate the tensioner counterclockwise (or in the direction that yields to spring pressure) to release the tension on the belt.
3. Remove the old belt: While holding the tensioner open, slip the belt off the easiest accessible pulley (usually the alternator or idler pulley). Slowly let the tensioner return to its resting position. Remove the old belt from the engine bay.
4. Route the new belt: Follow the routing path described in the section above, leaving the tensioner or alternator for last.
5. Install the new belt: Rotate the tensioner again with your breaker bar, slip the new belt over the final pulley, and carefully release the tensioner so it applies tension to the new belt.
6. Verify seating: Visually inspect every pulley to ensure the belt ribs are perfectly seated in the grooves. A misaligned belt will shred upon startup.
7. Test: Start the engine and let it idle. Watch the belt to ensure it runs smoothly without wobbling or squeaking.

Replacement interval

Modern EPDM (Ethylene Propylene Diene Monomer) serpentine belts are incredibly durable. For the 2017 GMC Acadia, the general replacement interval is between 60,000 and 90,000 miles. However, you should inspect the belt at every oil change once the vehicle surpasses 50,000 miles.

Signs of a failing belt or tensioner

Don't wait for the belt to snap and leave you stranded on the highway. Look and listen for these warning signs:

• Squealing or Chirping: A high-pitched squeal on startup or when accelerating usually indicates a stretched belt or a failing tensioner that can no longer maintain proper tension.
• Cracks and Fraying: While EPDM belts don't crack as noticeably as older neoprene belts, deep cracks, missing rib chunks, or frayed edges mean immediate replacement is necessary.
• Accessory Malfunctions: If your steering suddenly feels heavy, the A/C blows warm, or the battery light illuminates on your dash, your belt may have slipped off or snapped.
• Tensioner Bounce: With the engine running, look at the tensioner. If the arm is bouncing wildly, the internal spring or dampener is worn out, and the tensioner assembly must be replaced alongside the belt.

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