2021 Jeep Gladiator: Serpentine Belt Length & Routing

An essential component of your 2021 Jeep Gladiator's engine is the serpentine belt. This long, multi-ribbed belt drives crucial accessories, including the alternator, power steering pump, water pump, and air conditioning compressor. Over time, this rubber belt wears out and requires replacement. A failing belt or a bad tensioner can leave you stranded.

This guide covers the correct serpentine belt part numbers, routing, and replacement procedures for the 2021 Jeep Gladiator with either the 3.6L Pentastar V6 gas engine or the 3.0L EcoDiesel V6.

Note: Part numbers can vary based on your Gladiator's specific configuration (e.g., max towing package, optional high-output alternator). Always verify part numbers against your vehicle's VIN with your parts supplier or dealership before purchasing.

Quick Answer: 2021 Gladiator Belt & Pulley Part Numbers

Here are the common part numbers for the two available engines.

3.6L Pentastar V6 (Gas)

• Serpentine Belt Length: Approximately 2215mm to 2225mm
• Rib Count: 6-rib
• OEM Mopar Belt PN: 68449270AA
• Aftermarket Cross-References:
  • Gates: K060875
  • Dayco: 5060875
  • Continental: 4060875
• Auto-Tensioner Assembly PN: 68321657AA
• Idler Pulley PN: 68155943AB (Upper); 04627039AA (Lower)

3.0L EcoDiesel V6

• Serpentine Belt Length: Approximately 1700mm to 1710mm
• Rib Count: 6-rib
• OEM Mopar Belt PN: 68494539AA
• Aftermarket Cross-References:
  • Gates: K060670
  • Dayco: 5060670
  • Continental: 4060670
• Auto-Tensioner Assembly PN: 68494541AA
• Idler Pulley PN: 68225439AA

Belt Routing

Before you remove the old belt, take a clear photograph of the belt routing from a couple of angles. This will be your best guide for installing the new one. Since we cannot provide a visual diagram, follow this text-based path description carefully.

The belt is routed around a series of grooved and smooth pulleys. The back (smooth) side of the belt contacts smooth pulleys, while the ribbed side contacts grooved pulleys.

3.6L Gas Belt Routing

The routing for the 3.6L V6 is as follows:

1. Starts at the Crankshaft pulley (bottom center).
2. Wraps up and around the Air Conditioning Compressor (driver's side).
3. Goes down and under the Idler Pulley (lower driver's side).
4. Travels up to the Alternator (upper driver's side).
5. Crosses over to the Power Steering Pump (upper passenger side).
6. Goes down and around the Water Pump (center).
7. Finishes by wrapping under the Tensioner Pulley (passenger side) before returning to the Crankshaft.

3.0L Diesel Belt Routing

The diesel engine has a more compact accessory drive:

1. Starts at the Crankshaft pulley (bottom center).
2. Wraps up to the Alternator (upper passenger side).
3. Goes down and around the Water Pump (center).
4. Travels across to the Power Steering Pump (driver's side).
5. Goes down and around the Air Conditioning Compressor (lower driver's side).
6. Finishes by wrapping under the Tensioner Pulley before returning to the Crankshaft.

How to Replace the Serpentine Belt

Replacing the belt is straightforward with the right tool. You will need a serpentine belt tool, which provides extra leverage, or a long-handled 3/8" drive breaker bar.

1. Locate the Belt Tensioner: On both the 3.6L and 3.0L engines, the tensioner is a spring-loaded arm with a pulley on the end of it.
2. Find the Release Point: The tensioner arm has a 3/8" square hole designed to accept a breaker bar or serpentine belt tool.
3. Release Tension: Insert the tool into the square hole. For the 3.6L, you will typically rotate the tensioner clockwise (towards the passenger side) to release tension. For the 3.0L, you will rotate it counter-clockwise (towards the driver's side). As you rotate the arm, the belt will become loose.
4. Remove and Route: While holding the tension, slip the old belt off one of the smooth, accessible pulleys like the idler or alternator. Slowly release the tensioner arm. Route the new belt around all pulleys except for one easy-to-reach smooth pulley. Double-check that the belt is seated correctly in all the grooved pulleys. Apply tension again and slip the belt over the final pulley.

Replacement Interval

Jeep does not specify a strict mileage replacement for the serpentine belt, instead recommending regular inspections. As a general rule of thumb, most technicians recommend replacing the serpentine belt as a preventative measure every 80,000 to 100,000 miles.

However, you should inspect the belt during every oil change and replace it immediately if you notice any signs of wear.

Signs of a Failing Belt or Tensioner

Listen and look for these common warning signs:

• Squealing or Chirping Noises: This is the most common symptom, often indicating a worn or misaligned belt.
• Visible Wear: Look for cracks, glazing (shiny surface), fraying edges, or chunks of rubber missing from the ribs.
• Tensioner Noise: A bad bearing in the tensioner or idler pulley will make a grinding, rumbling, or whining noise that changes with engine RPM.
• Tensioner Arm Vibration: A failing tensioner spring will cause the tensioner arm to flutter or vibrate excessively while the engine is running.

Addressing a worn belt or failing tensioner early can prevent a breakdown and potential damage to other engine components.

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