2020 GMC Yukon Serpentine Belt Routing & Replacement Guide

Quick Answer

For the 2020 GMC Yukon with the 5.3L V8 engine, here are some key details for your serpentine belt:

• Belt Length: Approximately 98.5 inches (2502mm) - Always verify with your specific vehicle.
• Rib Count: 6-rib
• OEM Belt Part Number: AC Delco 12693006
• Aftermarket Cross-references:
  • Gates K060985
  • Dayco 5060985
  • Continental Elite 4060985
• Auto-Tensioner Part Number: AC Delco 12628469 (for 5.3L V8)
• Idler Pulley Part Number: AC Delco 12628045 (for 5.3L V8)

Note: Part numbers can vary based on engine size and specific options. Always confirm fitment with your VIN.

Belt Routing

Before you begin any work, take a clear photograph of your existing serpentine belt routing. This will be an invaluable reference during reinstallation.

The serpentine belt on your 2020 GMC Yukon (5.3L V8) winds its way around several accessories. Here's a common routing path. Remember that slight variations can exist, so your photo is crucial!

1. Starting from the crankshaft pulley at the bottom front of the engine.
2. The belt typically goes up and over the A/C compressor pulley.
3. From the A/C compressor, it usually drops down to pass under the idler pulley.
4. The belt then goes up and over the alternator pulley.
5. From the alternator, it will route down and around the power steering pump pulley.
6. Next, it generally goes up and over the water pump pulley.
7. Finally, the belt runs under the automatic tensioner pulley before returning to the crankshaft pulley, completing the loop.

How to Replace the Serpentine Belt

Replacing the serpentine belt on your 2020 GMC Yukon is a manageable DIY task for mostmechanics. You'll need a serpentine belt tool or a long 3/8" drive breaker bar.

1. Safety First: Ensure the engine is off and cool. Disconnect the negative battery terminal to prevent accidental starting.
2. Locate the Tensioner: Find the automatic tensioner pulley. It will have a square hole in its arm, usually 3/8" or 1/2".
3. Release Tension: Insert your serpentine belt tool or breaker bar into the square hole on the tensioner arm. Apply steady, downward (or sometimes upward, depending on tensioner orientation) pressure to pivot the tensioner and release tension on the belt.
4. Remove the Old Belt: While holding tension off the belt, carefully slip the old belt off one of the pulleys (often the idler or a smooth pulley is easiest).
5. Inspect Pulleys: Once the old belt is off, spin each pulley by hand. Listen for grinding noises and feel for excessive play or roughness. Replace any noisy or wobbly pulleys (idler, tensioner) as needed.
6. Route the New Belt: Referring to your photograph, meticulously route the new belt around all the pulleys, leaving the tensioner pulley (or another easily accessible pulley) for last.
7. Apply Tension: Again, use your serpentine belt tool or breaker bar to pivot the tensioner and create slack. Slip the new belt over the final pulley.
8. Verify Routing: Slowly release the tensioner and double-check that the belt is correctly seated in all pulley grooves. Ensure no part of the belt is hanging off or misaligned.
9. Reconnect Battery: Reconnect the negative battery terminal.
10. Test: Start the engine and let it run for a minute, observing the belt to ensure it tracks correctly and there are no unusual noises.

Replacement Interval

GMC generally recommends inspecting the serpentine belt at every oil change or major service interval (typically every 7,500 to 15,000 miles) and replacing it if signs of wear are present. Many technicians recommend proactive replacement between 60,000 to 100,000 miles, regardless of visible wear, as the rubber can degrade over time.

Signs of a Failing Belt or Tensioner

It's crucial to pay attention to your vehicle for signs of serpentine belt or tensioner issues, as failure can leave you stranded and damage other components.

Signs of a Failing Serpentine Belt:

• Squealing or Chirping Noises: This is one of the most common indicators. It can be due to a worn belt, misaligned pulleys, or a failing tensioner.
• Cracks, Fraying, or Glazing: Visible damage on the belt's surface. Small cracks are normal over time, but deep cracks or missing ribs indicate immediate replacement.
• Loss of Power Steering, A/C, or Charging: If the belt slips or breaks, the accessories it drives (power steering pump, A/C compressor, alternator, water pump) will stop working.
• Overheating: A broken belt means the water pump isn't circulating coolant, leading to engine overheating.

Signs of a Failing Tensioner:

• Belt Squeal: A weak tensioner might not keep adequate tension on the belt, leading to slippage and squealing.
• Belt Flutter or Vibration: If the tensioner isn't holding steady, you might see the belt fluctuate or vibrate excessively.
• Grinding or Rattling Noise from Tensioner: A failing tensioner pulley bearing can produce these sounds.
• Lack of Tension: Visually inspect the tensioner. If it's not applying sufficient pressure to the belt, it needs replacement.

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