2020 Jeep Grand Cherokee: Serpentine Belt Routing & Length

As an ASE-certified master technician, I've replaced countless serpentine belts. The belt that drives your accessories—alternator, A/C, power steering—is a critical component. This guide provides the essential details for replacing the serpentine belt on your 2020 Jeep Grand Cherokee.

Note that the 2020 Grand Cherokee was available with several engine options, most commonly the 3.6L V6 and the 5.7L V8. Part numbers differ between these engines. Always verify part numbers with your vehicle's VIN before purchasing.

Quick Answer

Here are the key specifications and part numbers for the serpentine belt and related components on the most common 2020 Jeep Grand Cherokee engines.

For models with the 3.6L V6 Engine:

• Belt Length: Approximately 2405mm
• Rib Count: 6-Rib
• OEM Mopar Belt PN: 5184323AC
• Aftermarket Cross-References: Gates K060947, Dayco 5060945, Continental 4060945
• Auto-Tensioner Assembly PN: Mopar 04862846AE
• Idler Pulley PN (smooth): Mopar 04862377AB

For models with the 5.7L V8 Engine:

• Belt Length: Approximately 2210mm
• Rib Count: 6-Rib
• OEM Mopar Belt PN: 53013953AC
• Aftermarket Cross-References: Gates K060870, Dayco 5060870, Continental 4060870
• Auto-Tensioner Assembly PN: Mopar 53032859AF
• Idler Pulley PN (smooth): Mopar 53013864AA

Belt Routing

Correctly routing the serpentine belt is crucial for proper function and to prevent damage. Before you remove the old belt, we strongly recommend taking a clear photograph of the existing belt routing with your phone. This will be your best guide.

If you can't, here is the typical text-based routing path. You will be wrapping the belt around a series of grooved and smooth pulleys.

1. Start by wrapping the grooved side of the belt around the Crankshaft Pulley at the bottom of the engine.
2. Move the belt up to the grooved pulley on the A/C Compressor.
3. Route the back (smooth side) of the belt against the smooth Idler Pulley.
4. Continue up to the grooved pulley on the Alternator.
5. Wrap the belt around the grooved pulley for the Power Steering Pump.
6. The belt then goes around the grooved pulley on the Water Pump.
7. Finally, the last component in the loop will be the smooth pulley on the Tensioner. This is the pulley you will move to get the final slack needed to install the belt.

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 pulley that keeps the belt tight.

To loosen the belt, you need to rotate the tensioner arm. On both the 3.6L and 5.7L engines, you will find a 3/8-inch square hole in the body of the tensioner. Insert a 3/8" drive breaker bar or a dedicated serpentine belt tool into this hole. Rotate the tensioner to relieve the belt's tension, slip the old belt off the pulleys, and carefully release the tensioner.

Route the new belt around all the pulleys, leaving the smooth idler or tensioner pulley for last. Using your tool again, rotate the tensioner, slide the belt over the final pulley, and double-check that the belt is correctly seated in the grooves of every pulley before starting the engine.

Replacement Interval

Modern serpentine belts are typically made of a durable EPDM rubber compound. While older neoprene belts had a shorter lifespan, a modern EPDM belt should be inspected regularly and is generally recommended for replacement between 75,000 and 100,000 miles. Check your Jeep’s owner manual for the specific factory recommendation. However, belts can fail prematurely due to heat, fluid contamination, or a failing tensioner.

Signs of a Failing Belt or Tensioner

Your vehicle will give you warning signs that the belt or tensioner needs attention.

• Squealing or Chirping: This is the most common sign, especially on cold starts or during sharp turns. It indicates the belt is slipping.
• Visible Wear: Look for cracks, fraying, glazing (shiny spots), or contamination from oil or coolant on the belt itself.
• Tensioner Pulley Wobble: The tensioner or idler pulleys should spin smoothly with no side-to-side wobble.
• Stiff or Weak Tensioner: The tensioner arm should move smoothly when you apply pressure with a tool and provide strong resistance. If it feels gritty, stuck, or weak, it needs to be replaced.
• Battery Light or Overheating: A failing belt can cause the alternator to stop charging the battery or the water pump to stop circulating coolant, leading to other immediate warnings.

Addressing serpentine belt issues promptly can save you from a breakdown and more expensive collateral damage.

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