🔧 3500 - Serpentine Belt Replacement

The serpentine belt on your 3500 drives accessories like the alternator, power steering, and A/C. Replacing it means releasing the automatic belt tensioner, swapping the belt, and making sure the belt ribs sit correctly on every pulley.

Difficulty Level: Intermediate | Estimated Time: 0.5-1.0 hours

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⚠️ Safety & Precautions

• ⚠️ Let the engine fully cool before working near the fan and pulleys.
• ⚠️ Keep fingers, hair, and clothing away from belt/pulleys at all times.
• ⚠️ Do not start the engine until tools are cleared from the engine bay.
• ⚠️ If you raise the front, support it with jack stands (never a jack alone).
• Note: Battery disconnect is not required for this job, but remove the key/fob from the vehicle and keep it away so the engine can’t be started accidentally.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Mechanic gloves
• Flashlight
• Serpentine belt tool (specialty)
• 15mm socket
• 3/8" drive ratchet
• 3/8" drive extension set
• 15mm box-end wrench
• Trim clip removal tool
• Flathead screwdriver
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Serpentine belt (accessory drive belt) - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Chock a rear wheel using wheel chocks.
• Open the hood and locate the belt routing diagram (usually on the radiator support/underside of hood). If it’s missing, take a clear photo of the current belt routing before removal.
• If access is tight, raise the front slightly using a floor jack (rated 3-ton minimum) and support with jack stands (rated 3-ton minimum).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm belt routing

• Use a flashlight to identify every pulley the belt wraps around.
• Take a photo with your phone for reference, even if there’s a diagram. Photos prevent routing mistakes.

Step 2: Create working room (if needed)

• If an intake snorkel/duct is blocking access, loosen clamps with a flathead screwdriver and remove any clips with a trim clip removal tool.
• Move the ducting aside without forcing it. Don’t crack plastic parts.

Step 3: Locate the automatic belt tensioner

• Use a flashlight and find the spring-loaded tensioner pulley (the arm moves against spring pressure).
• The tensioner will have either a 15mm hex head or a 3/8" square drive boss for a ratchet/belt tool.

Step 4: Release belt tension

• If your tensioner uses a hex head: place a 15mm socket on a 3/8" drive ratchet (use a 3/8" drive extension set if needed) and rotate the tensioner.
• If your tensioner uses a square drive boss: insert the 3/8" drive ratchet (or serpentine belt tool (specialty)) directly into the square opening and rotate the tensioner.
• Rotate smoothly and hold it—spring force is strong.
• With the tension released, slip the belt off the easiest-to-reach smooth pulley (often an idler) by hand while holding the tool in place.

Step 5: Remove the old belt

• Slowly let the tensioner return to its resting position (do not let it snap back).
• Pull the belt out of the engine bay, guiding it around the fan shroud area carefully.

Step 6: Quick pulley check

• Spin any easy-to-reach idler/tensioner pulleys by hand.
• If you feel roughness, grinding, wobble, or hear squealing, stop and tell me—those pulleys may need replacement before installing the new belt.

Step 7: Route the new belt

• Compare the new belt to the old belt for similar length and rib count.
• Route the belt according to the under-hood diagram (or your photo), leaving the easiest pulley for last.
• Make sure the ribbed side sits in the ribbed pulley grooves, and the smooth side rides on smooth pulleys.
• If one rib is off, it will shred.

Step 8: Apply tension and seat the belt

• Release the tensioner again using the 15mm socket and 3/8" drive ratchet (or serpentine belt tool (specialty)).
• Slip the belt onto the last pulley, then slowly let the tensioner return.
• Use a flashlight to verify the belt is centered on every pulley and fully seated in every groove.

Step 9: Reinstall anything you moved

• Reinstall the intake snorkel/ducting and tighten clamps with a flathead screwdriver.
• Reinstall any clips using a trim clip removal tool.

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✅ After Repair

• Start the engine and let it idle for 20–30 seconds while you watch the belt track.
• Listen for chirping/squealing and look for belt “wandering” side-to-side.
• Shut the engine off and do a final belt seating check with a flashlight.
• If the belt walks off-center or makes noise, stop—routing or a pulley issue is likely.

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💰 DIY vs Shop Cost

Shop Cost: $180-$320 (parts + labor)

DIY Cost: $35-$85 (parts only)

You Save: $95-$285 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hours.

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🎯 Ready to get started?

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