2015 Ram ProMaster Serpentine Belt Routing & Length

As an ASE-certified master technician, I regularly service fleet vehicles, and the 2015 Ram ProMaster is one of the most common commercial vans in the bay. Powered predominantly by the dependable 3.6L Pentastar V6 (a 3.0L EcoDiesel was also available, but the V6 is standard), this front-wheel-drive workhorse relies heavily on its serpentine belt to keep critical accessories like the alternator, water pump, power steering, and A/C compressor running smoothly.

If you are experiencing a squealing noise from the passenger side of the engine bay, or if it is simply time for preventative maintenance, this reference guide provides all the specifications, part numbers, and routing instructions you need for the 3.6L V6 Ram ProMaster.

Quick answer

For the 2015 Ram ProMaster equipped with the 3.6L Pentastar V6 engine, here are the exact specifications and part numbers you need:

• Belt Length: 79.08 inches (approx. 2009 mm)
• Rib Count: 6-rib
• OEM Belt Part Number: Mopar 5184081AD
• Aftermarket Belt Cross-References: Gates K060790, Dayco 5060790, Continental Elite 4060790
• Auto-Tensioner Part Number: Mopar 5184083AD (Aftermarket: Gates 39227)
• Idler Pulley Part Number: Mopar 5184080AF (Aftermarket: Gates 36622)

(Note: If you have the rare 3.0L EcoDiesel model, your belt specifications and part numbers will differ completely. Always verify with your parts supplier using your VIN.)

Belt routing

Because we cannot render an image here, it is highly recommended that you take a clear photograph of your existing belt routing with your smartphone before you begin removal. This simple step can save you massive headaches during reinstallation.

For the 3.6L V6 ProMaster, the drive belt routes in the following path:

1. Start at the Crankshaft Pulley (bottom center).
2. Route the belt down and around the A/C Compressor (bottom front).
3. Bring the belt up and over the ribbed Idler Pulley.
4. Continue up and around the Alternator (top front).
5. Route it across the top and around the Power Steering Pump (top rear).
6. Bring the belt straight down around the smooth pulley of the Water Pump.
7. Finally, loop the belt inside and around the Auto-Tensioner before meeting back at the Crankshaft Pulley.

Make sure the ribbed side of the belt rides on ribbed pulleys (crank, A/C, alternator, power steering) and the smooth side rides against smooth pulleys (idler, water pump, tensioner).

How to replace the serpentine belt

Working on the transverse-mounted 3.6L in the ProMaster can be slightly cramped, but replacing the belt is straightforward if you have the right tools.

1. Gain Access: Open the hood and locate the belt drive system on the passenger side of the engine bay.
2. Relieve Tension: Locate the automatic belt tensioner. Using a specialized serpentine belt tool or a long 3/8" drive breaker bar, insert the square drive into the tensioner arm's slot. Rotate the tensioner counter-clockwise (towards the front of the vehicle) to relieve tension on the belt.
3. Remove the Belt: Slip the old belt off the easiest accessible pulley (usually the idler or alternator). Carefully release the tensioner back to its resting position. Pull the old belt out of the engine bay.
4. Route the New Belt: Following your photograph or the routing path described above, snake the new belt around all the pulleys except for the final idler or alternator pulley.
5. Final Installation: Rotate the tensioner again with your breaker bar, slip the belt over the final pulley, and slowly release the tensioner so it clamps down on the belt. Double-check every pulley to ensure the belt ribs are perfectly seated in the grooves.

Replacement interval

For the 2015 Ram ProMaster 3.6L, the manufacturer generally recommends inspecting the belt every 20,000 miles. However, as a best practice for fleet and commercial vehicles, I recommend a strict replacement interval of 60,000 to 90,000 miles. Modern EPDM belts don't crack the way old neoprene belts did; instead, the ribs wear down like tire tread.

Signs of a failing belt or tensioner

Don't wait for the belt to snap and leave you stranded on a job site. Look out for these warning signs:

• Squealing or Chirping: Especially prominent on cold startups or when the A/C compressor engages. This indicates a worn belt or a weak tensioner spring.
• Heavy Steering: If the belt slips on the power steering pump, your steering wheel will feel incredibly stiff.
• Overheating or Battery Warning Lights: If the belt is slipping over the water pump or alternator, your engine will run hot and your battery won't charge.
• Visible Wear: Use a belt wear gauge. If the ribs are too shallow, or if you see missing chunks of rubber (pilling), replace the belt immediately.

If you don't have the tools, the time, or the patience to tackle this job yourself, don't worry. Find a trusted shop on Repairius.