2020 Jeep Wrangler — Serpentine Belt Routing & Length

Quick answer

• Belt length and rib count
  • 3.6L Pentastar V6 (most common, non‑eTorque): 6‑rib; belt length typically in the mid‑90 inch range (about 96–97 in). Always confirm by VIN.
  • 3.6L Pentastar V6 (eTorque): 6‑rib main accessory belt; separate eTorque/BISG belt present. Lengths vary—confirm by VIN.
  • 2.0L Turbo I4 (non‑eTorque): 6‑rib; length varies by accessory package (generally mid/upper‑80s to low‑90s inches). Confirm by VIN.
  • 2.0L Turbo I4 (eTorque): 6‑rib main accessory belt plus separate eTorque belt; verify both by VIN.
  • 3.0L EcoDiesel V6: Rib count and length differ from gas engines; confirm by VIN.
• OEM belt part number (Mopar): Varies by engine/eTorque and A/C. Use the VIN in a Mopar catalog or dealer counter to confirm the exact PN. Do not order by guesswork.
• Aftermarket belt cross‑refs (choose the exact length that matches your VIN):
  • Gates: K06xxxx series (6‑rib) or appropriate 7/8‑rib for EcoDiesel/eTorque sub‑belts
  • Dayco: 506xxxx series (6‑rib) or matching x‑rib family as required
  • Continental: 406xxxx series (6‑rib) or matching x‑rib family as required
• Automatic tensioner (Mopar) PN: Application‑specific (differs by engine/eTorque). Confirm by VIN.
• Idler pulley (Mopar) PN: Application‑specific. Confirm by VIN.

Note: 2020 Wrangler (JL) offered multiple engines and eTorque options. The belt, tensioner, and idlers are not universal. The most accurate way to source parts is by VIN.

Belt routing

Before you remove the old belt, take a clear photo of its path. Under‑hood decals are helpful, but photos of your exact vehicle are better.

Typical JL routing (schematic order shown for reference):

• Crankshaft pulley → A/C compressor → idler pulley → alternator → power steering → water pump → automatic tensioner → back to crankshaft pulley.

Depending on engine and accessory layout, one or more pulleys may sit on the belt’s back side (smooth) or ribbed side, and the idler/tensioner positions may mirror this path. Use your photo and under‑hood diagram to confirm orientation as you install the new belt.

How to replace the serpentine belt

Tools and supplies

• Serpentine belt tool or a 3/8" drive breaker bar/ratchet that fits the tensioner
• New belt (and, if needed, new tensioner and idler pulleys)
• Small flashlight and gloves

Steps

1. Photograph the existing routing from a couple of angles.
2. Identify the tensioner. Most JL tensioners accept a 3/8" square drive. Insert the tool and rotate the tensioner to relieve belt tension.
3. Slip the belt off the easiest upper pulley (often the alternator) while holding the tensioner released. Slowly let the tensioner return.
4. Remove the old belt and compare length/rib count to the replacement.
5. Route the new belt following your photo and the under‑hood diagram. Leave the easiest upper pulley for last.
6. Rotate the tensioner again, slip the belt fully onto the last pulley, and release the tensioner slowly.
7. Double‑check that the belt is seated in every pulley groove and centered on smooth idlers.
8. Start the engine and observe for 20–30 seconds. The belt should run true with no chirps, flaps, or wobble. Shut down and re‑inspect alignment.

Tip: If the belt was off due to a coolant or oil leak, fix the leak first—fluids degrade belt rubber and squeal will return.

Replacement interval

• Time/mileage: Inspect every oil change and plan replacement around 90,000–100,000 miles or 6–7 years, whichever comes first. Many belts last longer in mild climates, but age‑hardening and glazing raise the risk of sudden failure.
• Tensioner/idlers: Replace proactively with the second belt, or immediately if bearings feel rough, pulleys wobble, or the tensioner arm is weak/jumpy.

Signs of a failing belt or tensioner

• Belt cracks, chunking, missing ribs, or heavy glazing/shiny rib surfaces
• Chirping/squealing on cold start, especially in wet weather
• Power steering effort changes, dimming lights, or intermittent battery light (belt slip/alternator underdrive)
• Overheating at idle with A/C on (water pump underdrive from slip)
• Belt dust around the front timing cover or accessory brackets
• Tensioner arm fluttering at idle, or weak return when you apply/release the tool
• Idler/tensioner pulley noise: growl, rumble, or roughness when spun by hand (engine off)

Engine‑option variation (read before ordering)

• 3.6L Pentastar V6: 6‑rib main belt; routing similar to the path described above. Length differs with A/C and model year updates.
• 2.0L Turbo I4: 6‑rib main belt. eTorque models add a separate belt for the motor‑generator (different rib count/length).
• 3.0L EcoDiesel V6: Accessory layout, rib count, and belt length differ from gas engines; verify specifically by VIN.

Because Mopar supersedes part numbers over time and JL configurations vary, use your VIN in a Mopar catalog (or ask a dealer/quality parts supplier) to confirm:

• Exact belt PN and length
• Correct automatic tensioner PN
• Correct idler pulley PN(s)
• If equipped with eTorque: the additional eTorque belt PN and any related idlers

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