2021 Ram ProMaster Serpentine Belt Guide

Quick Answer

• Belt Length & Rib Count: 96.0" (2438 mm), 6-rib
• OEM Belt Part Number: Mopar 04893902AB
• Aftermarket Belt Part Numbers: Gates K060960, Dayco 5060960, Continental 4060960
• Automatic Tensioner Part Number: Mopar 04893427AB
• Idler Pulley Part Number: Mopar 04893792AA

Belt Routing

Before you remove the old belt, we strongly recommend taking a clear photograph of the belt's path for reference.

The 3.6L Pentastar V6 in the 2021 ProMaster routes its serpentine belt in the following order:

1. Starts at the crankshaft pulley at the bottom of the engine.
2. Wraps around the A/C compressor pulley.
3. Goes up and around the idler pulley.
4. Travels to the alternator pulley.
5. Comes down to the power steering pump pulley.
6. Goes across to the water pump pulley.
7. Finally, loops under the automatic tensioner before returning to the crankshaft pulley.

How to Replace the Serpentine Belt

Replacing the serpentine belt on the ProMaster's 3.6L V6 is straightforward. You will need a serpentine belt tool or a long-handled 3/8" breaker bar to release the tension on the belt.

Locate the automatic tensioner—it has a 3/8" square hole designed to accept the tool. Insert your breaker bar or serpentine belt tool into this hole. Rotate the tensioner pulley away from the belt to loosen it. While holding the tension, slip the old belt off one of the pulleys (the top-most alternator pulley is often easiest). Slowly release the tensioner.

Use your routing photo and the diagram above to route the new belt around all pulleys, leaving the smooth idler pulley for last. Release the tension again and slide the new belt onto the final pulley. Double-check that the belt is centered in the grooves of all ribbed pulleys before starting the engine.

Replacement Interval

While there is no universally mandated replacement interval, a general best practice is to inspect the serpentine belt at every oil change and consider replacement every 60,000 to 90,000 miles. Driving in harsh conditions (extreme heat, dust) may require more frequent replacement.

Signs of a Failing Belt or Tensioner

It's critical to replace a worn belt before it fails, as a broken belt will immediately disable your van. Watch for these warning signs:

• Visible Wear: Look for cracks, fraying, glazing (a shiny, smooth appearance), or missing ribs on the belt.
• Chirping or Squealing Noises: This often indicates a worn, misaligned, or improperly tensioned belt. While sometimes caused by moisture, persistent noise means the belt or tensioner needs attention.
• Failing Accessories: Since the belt drives the alternator, power steering, and water pump, a failing belt can cause dim headlights, difficulty steering, or a rise in engine temperature.
• Tensioner Issues: A failing tensioner may not hold adequate tension, causing the belt to slip. You may notice the tensioner pulley vibrating erratically or hear a grinding/rumbling noise from its bearing.

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