2022 Ford F-350 Super Duty Serpentine Belt Guide

Quick Answer

• Belt Length and Rib Count: Varies by engine. The 6.2L V8 typically uses a 102.0-inch belt with 6 ribs. The 7.3L V8 often uses a 99.5-inch, 6-rib belt. The 6.7L Power Stroke diesel uses a more complex dual-alternator system with a main belt around 105 inches and a secondary belt around 45 inches, both 8-rib.
• OEM Belt Part Numbers: These are engine-specific. For the 6.2L, look for Ford part numbers like JC3Z-8620-A. For the 7.3L, you might see LC3Z-8620-A. For the 6.7L diesel, the main belt could be similar to JC3Z-8620-B.
• Aftermarket Cross-References:
  • 6.2L V8: Gates K061020, Dayco 5061020, Continental 4061020.
  • 7.3L V8: Gates K060995, Dayco 5060995, Continental 4060995.
  • 6.7L Diesel (Main): Gates K081050, Dayco 5081050.
• Auto-Tensioner Part Number: For the 6.2L and 7.3L engines, a common part is Motorcraft BT-120 or similar. The 6.7L diesel uses a more robust tensioner, often part number BC3Z-6B209-E.
• Idler Pulley Part Number: A common idler pulley for the gas engines is Motorcraft YS-373. The diesel engine uses different idlers, like the smooth idler pulley part number JC3Z-8678-A.

Note: Always verify part numbers with your VIN at a local dealer or parts supplier before purchasing, as variations exist based on accessories and alternator options.

Belt Routing

Properly routing the serpentine belt is critical for the function of your F-350’s engine accessories. Before you remove the old belt, always take a clear photograph of the current routing from a couple of angles. This will be your best guide.

For a common single-alternator gas engine (6.2L or 7.3L), the belt path is as follows:

1. Starts at the main crankshaft pulley at the bottom.
2. Wraps up and around the A/C compressor pulley.
3. Goes down and under the smooth idler pulley.
4. Travels up to the alternator pulley.
5. Comes across to the power steering pump pulley.
6. Goes down to the water pump pulley.
7. Finally, loops around the automatic tensioner pulley, which applies pressure to keep the belt taut.

The 6.7L Power Stroke diesel engine has a more complex routing, especially on dual-alternator models. It is crucial to photograph this setup or have a diagram handy before proceeding.

How to Replace the Serpentine Belt

Replacing the belt is a manageable task for a DIYer with the right tool. You will need a serpentine belt tool, which is a long, thin ratchet with various socket and crowfoot attachments. In many cases, a standard 3/8" or 1/2" drive breaker bar can also be used.

1. Safety First: Make sure the engine is cool.
2. Locate the Tensioner: Find the automatic tensioner—it’s the pulley on a spring-loaded arm.
3. Release Tension: Fit your serpentine belt tool or breaker bar into the square hole on the tensioner arm. Rotate the tensioner arm to release the belt's tension. The direction of rotation depends on the engine, but you will feel the spring engage.
4. Remove Old Belt: While holding the tensioner, slip the old belt off one of the smooth, non-lipped pulleys, like the idler or water pump.
5. Check Pulleys: With the belt off, spin each pulley by hand (except the crank). They should spin smoothly and silently. A rough, noisy, or wobbly pulley indicates a bad bearing, and the pulley (or the entire accessory) should be replaced.
6. Install New Belt: Using your photo or a diagram, route the new belt around all pulleys except for one easy-to-reach, smooth pulley (like the idler).
7. Apply Tension: Once the belt is correctly routed, release the tensioner arm again and slip the belt over the final pulley. Double-check that the belt is centered in the grooves of every ribbed pulley.
8. Final Check: Release the tensioner slowly, ensuring the belt seats correctly and is taut. Start the engine for a few seconds to confirm everything is operating smoothly.

Replacement Interval

Ford recommends inspecting the serpentine belt at regular service intervals. While modern belts are durable and can last 100,000 miles or more, a good rule of thumb is to replace the belt every 60,000 to 90,000 miles, or as soon as it shows signs of wear. Given the heavy-duty nature of the F-350, being proactive is wise.

Signs of a Failing Belt or Tensioner

Watch for these symptoms to avoid a breakdown:

• Squealing or Chirping Noises: This is the classic sign of a slipping, misaligned, or worn belt. The noise may be worse on cold starts or in wet weather.
• Visible Wear: Inspect the belt for cracks, fraying, glazing (shiny spots), or missing ribs.
• Accessory Malfunctions: If you notice dimming headlights (alternator), difficulty steering (power steering), or the engine temperature rising (water pump), the belt could be slipping or broken.
• Tensioner Noise or Vibration: A growling or rattling noise from the tensioner area points to a failing bearing. You may also see the tensioner arm vibrating excessively while the engine is running. A weak tensioner spring can cause belt slip even if the belt is new.

If you're not comfortable performing this service yourself, you can find a trusted local shop to handle it for you.

Find a trusted shop on Repairius.