How often should the serpentine belt be changed?
March 13, 2025

How often should the serpentine belt be changed?

Regular inspection of all drive belts, tensioners and accessories should be recommended once the vehicle passes 60,000 miles. And when the belt is worn and ready for replacement, which is typically around 90,000 miles, the pulley and tensioner should also be replaced. That’s because the drive works as a system. Replacing only the belt will often result in short belt life because the tensioner likely…
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What should I do if the belt is making a squealing noise?
March 13, 2025

What should I do if the belt is making a squealing noise?

A squeal is usually caused by low bely tension or contamination. To rectify the problem, we suggest the following steps: Properly tension manual applications during installation (35 lbs. per rib) and then re-tension after 5 minutes of run-in (30 lbs. per rib). This allows the belt to seat in the pulleys. On vehicles with automatic belt tensioners, the tensioner pulley should turn freely without binding.…
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What should I do if my belt is making a chirping noise?
March 13, 2025

What should I do if my belt is making a chirping noise?

There’s a few possible causes for a chirp: pulley misalignment, improper installation, extremely worn belt ribs, worn pulley bearings or contamination. We suggest the following solutions: Check alignment of all pulleys, either with a straight edge or a laser alignment tool. Ensure all accessory pulleys and brackets are tightened snug to mounting surfaces. Inspect and replace all accessories/pulleys that are difficult to rotate (i.e. rough/seized…
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My serpentine belt is making a noise. How do I determine what’s causing it?
March 13, 2025

My serpentine belt is making a noise. How do I determine what’s causing it?

There are two very distinct noises caused by different issues - one is a chirp, the other is a squeal. Your best course of action is to conduct a water test to see which one you are dealing with. With the vehicle idling, spray water on the belt’s rib surface. Then listen closely. If you hear a sharp, high-pitched, repetitive noise of short duration that is…
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I installed a serpentine belt a couple of days ago and it broke. What did I do wrong?
March 13, 2025

I installed a serpentine belt a couple of days ago and it broke. What did I do wrong?

When a belt breaks quickly after installation, it is likely due to one of the four reasons: It was not 100% seated in a pulley. Worn pulley bearings caused the belt to “walk off” the pulley surface. A damaged pulley could have ‘cut’ the belt. A malfunctioning tensioner caused belt misalignment and damage. Be sure to check the tension and fit before completing the job…
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On a timing belt repair, which timing mark is for the camshaft and which is for the crankshaft?
March 13, 2025

On a timing belt repair, which timing mark is for the camshaft and which is for the crankshaft?

Most timing belts will have two double dotted line marks and 4 to 6 solid marks. Double dotted lines are for the crankshaft, and the solid line is for camshaft alignment. Dayco includes detailed instructions with all timing kits so follow the instructions closely as they vary by make and model. Proper timing belt installation is critical to engine performance and long belt life. A…
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How do I know if my timing belt has been replaced?
March 13, 2025

How do I know if my timing belt has been replaced?

Without maintenance history of a car, the best possible way is to check CarFax for a repair history report, ask the previous owner, or look for a sticker under the hood indicating it has been changed. If all these fail, best course is to have a technician inspect it. Some OEMs recommend replacement as early as 30,000 miles, while others suggest maintenance around 100,000 miles.…
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How do I check for belt wear?
March 13, 2025

How do I check for belt wear?

Belt wear can be difficult to detect because newer belts made with EPDM rubber tend to wear like tire tread, where there is material loss from the rib surface. A new belt will have a traditional “V” profile in the grooves between the ribs. On a worn EPDM belt, however, the groove profile will have the appearance of a “U”. One of the best ways…
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Where do I find belt routing diagrams?
March 13, 2025

Where do I find belt routing diagrams?

Dayco has more than 16,000 belt routing diagrams available on its Find Your Part search platform. If you come across a specific part number that does not have a diagram, and you can't find it online or under the hood, feel free to use the Contact Us form and let us know the year, make and model and we’ll look it up and email it to you the same…
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