2016 GMC Yukon Serpentine Belt: Routing, Part Numbers & Replacement Guide

Quick Answer

Here are the essential part numbers and specifications for servicing the serpentine drive belt on a 2016 GMC Yukon, Yukon XL, or Yukon Denali equipped with either the 5.3L V8 or 6.2L V8 engine.

• Serpentine Belt Length: 92.5 inches (2350mm)
• Rib Count: 6-rib
• OEM Serpentine Belt PN: GM 12658178
• Aftermarket Belt Cross-References:
  • Gates: K060925
  • Dayco: 5060925
  • Continental Elite: 4060925
• Automatic Belt Tensioner PN: GM 12670921
• Idler Pulley PN: GM 12628025

Belt Routing

Before you remove the old belt, we strongly recommend taking a clear photograph of the belt's path with your phone. This simple step can save you a significant amount of time and frustration during reassembly. A sticker with the routing diagram may also be present on the radiator support or fan shroud.

The serpentine belt on the 2016 Yukon follows a specific path to power all the engine-driven accessories. Starting from the main crankshaft pulley at the bottom center of the engine, the belt travels:

1. Up and around the A/C Compressor pulley (bottom passenger side).
2. Down and under the smooth Idler Pulley (located just below and to the right of the alternator).
3. Up and over the Alternator pulley (top passenger side).
4. Across to the Power Steering Pump pulley (top driver's side).
5. Down and around the grooved Water Pump pulley (center of the engine).
6. Finally, down to the Automatic Tensioner pulley (bottom driver's side) before returning to the crankshaft pulley.

How to Replace the Serpentine Belt

Replacing the serpentine belt is a manageable task for a DIYer with the right tool. The key is the automatic belt tensioner, which has a spring-loaded arm designed to keep constant pressure on the belt. To release this tension, you'll need a serpentine belt tool or a long-handled 3/8" drive breaker bar.

Locate the square 3/8" drive hole in the body of the tensioner assembly. Insert your tool and rotate the tensioner clockwise (towards the passenger side of the vehicle). This will swing the tensioner pulley down and away from the belt, creating enough slack to slip the belt off one of the top accessory pulleys, like the alternator or power steering pump.

Once the old belt is off, carefully route the new belt according to the path described above, leaving one of the easily accessible top pulleys for last. Double-check that the ribs of the belt are correctly seated in the grooves of every ribbed pulley. Once you are certain the routing is correct, use your tool to release the tensioner again and carefully slide the belt over the final pulley. Slowly release the tool, allowing the tensioner to apply pressure to the new belt. Give the entire belt path one final visual inspection before starting the engine.

Replacement Interval

Modern EPDM rubber serpentine belts are incredibly durable. General Motors does not specify a strict replacement mileage, instead recommending regular inspections during routine oil changes. As a rule of thumb, most technicians recommend replacing the serpentine belt as a preventative measure between 75,000 and 100,000 miles, or every 10 years, whichever comes first. For vehicles operated in extreme heat or cold, earlier replacement may be wise.

It is highly recommended to replace the belt tensioner and the idler pulley at the same time as the belt, especially on a higher-mileage vehicle. The bearings in these pulleys wear out over time, and a seized pulley will destroy a new belt almost instantly, leaving you stranded.

Signs of a Failing Belt or Tensioner

Listen and look for the warning signs of a worn drive belt system:

• Chirping or Squealing: A constant high-pitched noise from the front of the engine is the most common sign of a worn belt or a weak tensioner.
• Visible Wear: Inspect the belt for cracks, fraying, glazing (shiny, smooth surface), or missing chunks of the rubber ribs. Any visible damage warrants immediate replacement.
• Tensioner Pulley Wobble: With the engine off, check the tensioner and idler pulleys for any side-to-side play or roughness when spun by hand. With the engine running, a failing tensioner may cause the tensioner arm to bounce or vibrate erratically.
• Accessory Malfunctions: Since the belt drives everything from the alternator to the power steering pump, a failing belt can cause intermittent issues like dimming headlights, a "Battery Not Charging" warning, or difficulty steering.

If you're not comfortable performing this service yourself, you can find a trusted and certified repair facility in your area.

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