2015 Jeep Wrangler Serpentine Belt Routing & Length

As an ASE-certified master technician, I’ve replaced countless drive belts on the 3.6L Pentastar V6 engine. The 2015 Jeep Wrangler is a rugged off-roader, but its reliability off the beaten path relies heavily on a healthy serpentine belt system. If your belt snaps on a trail, you lose power steering, alternator charging, and your water pump—a recipe for overheating and a long walk home.

Here is the definitive guide to the serpentine belt routing, part numbers, and replacement procedures for the 2015 Jeep Wrangler (3.6L V6).

Quick Answer: Belt Specs & Part Numbers

• Rib Count: 6-rib
• Belt Length: 60.2 inches (effective length)
• OEM Belt Part Number: Mopar 05168407AA / 05168407AB
• Aftermarket Cross-References: Gates K060602, Dayco 5060603, Continental Elite 4060602
• Auto-Tensioner Part Number: Mopar 05186251AA (Gates 39316)
• Idler Pulley Part Number: Mopar 05186255AA (Gates 36198)

Belt Routing

Pro Tip: Before removing the old belt, always take a clear photo of the existing routing with your smartphone just in case you get mixed up.

Because the 3.6L Pentastar engine is tightly packed into the Wrangler's engine bay, knowing the exact path of the belt is critical. Here is the step-by-step text description of the belt routing:

1. Start by looping the belt around the bottom of the Crankshaft Pulley.
2. Route the belt straight up from the left side (driver's side) of the crank over the Water Pump Pulley.
3. From the water pump, go across the top and loop over the Alternator Pulley.
4. Bring the belt straight down from the alternator and under the smooth Idler Pulley.
5. Pull the belt up and over the Power Steering Pump Pulley.
6. Route it down and around the A/C Compressor Pulley (at the bottom right/passenger side).
7. Finally, pull the remaining loop of the belt up to the Auto-Tensioner Pulley (the tensioner sits above the A/C compressor). You will relieve the tension to slide the belt onto this final pulley.

How to Replace the Serpentine Belt

Replacing the belt on a 2015 Jeep Wrangler 3.6L requires working in a relatively tight space, especially with the air intake tube in the way.

Tools Needed:

• 3/8" drive breaker bar or a dedicated long-handle serpentine belt tool
• Flathead screwdriver or 10mm socket (to remove the air intake tube for better access)

Procedure:

1. Clear the way: Remove the air intake hose that runs from the airbox to the throttle body. This gives you much better access to the front of the engine.
2. Release Tension: Insert your 3/8" breaker bar or serpentine belt tool directly into the square drive hole on the front of the automatic belt tensioner.
3. Remove the Belt: Rotate the tensioner counterclockwise (towards the driver's side) to relieve pressure on the belt. Slip the belt off the easiest accessible pulley (usually the idler or alternator).
4. Inspect Pulleys: With the belt off, spin the idler pulley, tensioner pulley, alternator, and water pump by hand. Listen for grinding noises and check for lateral play. If the tensioner is weak or the idler bearings are rough, replace them now.
5. Install the New Belt: Route the new belt according to the path described in the routing section above, leaving the tensioner pulley for last.
6. Apply Tension: Rotate the tensioner counterclockwise again, slip the belt onto the tensioner pulley, and slowly release the tensioner to apply pressure.
7. Final Check: Verify the belt is seated squarely in the grooves of all the ribbed pulleys. Reinstall your air intake tube. Start the engine and verify smooth operation.

Replacement Interval

For the 2015 Jeep Wrangler 3.6L, the factory maintenance schedule recommends inspecting the drive belt at 20,000 miles or 2 years, but modern EPDM belts typically last between 60,000 and 90,000 miles. If you frequently take your Wrangler off-roading through deep mud, water, or dusty environments, abrasive dirt can wear out the belt and pulley bearings much faster. I recommend replacing the belt and checking the tensioner every 60,000 miles under severe duty.

Signs of a Failing Belt or Tensioner

Don't wait for the belt to snap. Look and listen for these warning signs:

• High-Pitched Squealing: Usually heard at startup, indicating a loose or glazed belt, or a tensioner that has lost its spring force.
• Visible Wear: Look for fraying edges, deep cracks (more than 3 cracks per inch in the ribs), or chunks of rubber missing. Modern EPDM belts don't crack as much as older neoprene belts; instead, the ribs wear down.
• Whirring or Grinding Noises: A constant metallic whine or grinding sound indicates a failing bearing in the idler pulley or tensioner.
• Belt Tracking Issues: If the belt is riding off the edge of a pulley, the auto-tensioner arm is likely bent or the internal spring is failing.

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