2019 Ram 1500 — Serpentine Belt Routing & Length

Quick answer

• Belt length and rib count
  • Varies by engine and whether the truck is a “DT” (new‑body 2019) with eTorque or a “Classic/DS.” Most accessory drive belts are 6‑rib; eTorque motor‑generator (MG) drive belts are typically wider (often 8‑rib) and separate from the accessory belt. Lengths span roughly mid‑90s to mid‑110s inches depending on engine/accessories.
• OEM serpentine belt part number
  • Differs by engine (3.6L V6, 5.7L HEMI w/ or w/o eTorque, 3.0L EcoDiesel on Classic). Use your VIN at a Mopar parts counter or Mopar’s online catalog to confirm the exact PN printed on your under‑hood label.
• Aftermarket cross‑references (examples by family—confirm by VIN before purchase)
  • Gates Micro‑V: K06xxxx (6‑rib accessory belt family), K08xxxx (8‑rib MG/eTorque belt family)
  • Dayco Poly‑Cog/Serp: 506xxxx (6‑rib), 508xxxx (8‑rib)
  • Continental/Multi‑V: 406xxxx (6‑rib), 408xxxx (8‑rib)
• Automatic tensioner PN
  • Application‑specific. Use VIN to match (tensioners differ between 3.6, 5.7, eTorque vs non‑eTorque, and Classic vs DT). Look for OE Mopar or quality equivalents (Gates DriveAlign, Dayco).
• Idler pulley PN
  • Application‑specific. Verify by VIN. Many 2019 configurations use one smooth idler plus the spring tensioner pulley.

Note: 2019 is a split year. The Ram 1500 “DT” (new body) and “Classic/DS” (prior gen) use different belts, pulleys, and tensioners. eTorque trucks add a separate belt for the motor‑generator. Never order parts without confirming by VIN and build configuration.

Belt routing

Because we can’t render an image here, use this text path as a reference and photograph your existing belt before removal. A common 2019 Ram 1500 accessory routing is:

Crankshaft pulley (harmonic balancer) → A/C compressor → smooth idler → alternator → power steering pump → water pump → automatic tensioner → back to crank.

• The back (ribbed side) of the belt rides on grooved pulleys (crank, alternator, power steering, A/C).
• The smooth side of the belt rides on smooth idlers/tensioner where applicable.
• eTorque models have a separate MG belt and tensioner that do not share the full accessory routing above—do not mix the MG belt path with the accessory belt.

How to replace the serpentine belt

Tools: serpentine belt tool or a 3/8" breaker bar/ratchet that fits the square drive in the tensioner arm; good lighting; belt routing photo.

1. Record the routing. Take a clear photo of the current belt routing and note which pulleys are smooth vs grooved.
2. Relieve tension. Insert the 3/8" drive tool into the tensioner, rotate the tensioner to unload the belt, and slide the belt off one easy‑to‑reach smooth pulley.
3. Remove the old belt. Snake it out of the accessory drive. If equipped with eTorque, confirm you are removing the accessory belt, not the MG belt (separate path).
4. Inspect components. Spin the idler(s) and tensioner pulley by hand—listen/feel for roughness, play, or noise. Check the tensioner arm for smooth movement and proper return. Inspect the water pump, alternator, and power steering pulleys for wobble or misalignment.
5. Route the new belt. Following your photo and the path above, route the belt around all pulleys except the final easy‑access smooth pulley. Ensure the ribs are fully seated in every grooved pulley.
6. Set tension. Rotate the tensioner again, slip the belt over the last pulley, and slowly release the tensioner. Double‑check alignment in every groove.
7. Start and verify. Briefly start the engine and observe the belt tracking. Shut down and recheck seating.

Tip: If the under‑hood routing decal differs from the text path, follow the decal for your exact engine/accessory configuration.

Replacement interval

• Inspect at every oil change; replace around 90,000–100,000 miles or 6 years, whichever comes first. Trucks exposed to dust, heat, or towing duty may need earlier replacement.
• eTorque MG belts often wear differently; inspect both the accessory and MG belts.

Signs of a failing belt or tensioner

• Belt: glazing/shiny ribs, fraying, chunks missing, cracking across ribs, or chirp/squeal at startup or with A/C load.
• Tensioner/idler: rattling, chirping that changes with A/C or steering load, visible tensioner “bounce,” pulley wobble, or red/brown dust (bearing wear). A weak tensioner often causes rapid belt glaze and noise.
• Alignment issues: belt walking off a pulley, rib edge wear, or a pulley that doesn’t sit in the same plane as the others.

Engine‑option variation you must confirm

• 3.6L Pentastar V6 (DT often with eTorque; Classic typically without): different belt lengths/tensioners.
• 5.7L HEMI V8: distinct part sets for non‑eTorque vs eTorque; MG belt is separate on eTorque.
• 3.0L EcoDiesel (Classic/DS only in 2019): unique belt/tensioner layout.

Have your 17‑digit VIN handy and confirm: body style (DT vs Classic/DS), engine, A/C presence, and eTorque. Cross‑check the under‑hood belt sticker with the catalog listing before ordering.

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