How to Stop Fan Belt Squealing (For Good)

If you have a noisy fan belt you are in the right place. This video will help you understand the different types of noises coming from your fan belt and how to start troubleshooting. Identify the real cause of the fan belt noise and fix the issue for good.

Fan Belt Noise Causes & Solutions

Don’t (Always) Blame the Belt!

fan belt

Fact: Noise from an accessory drive is not usually the fault of the belt!

  • Several types of noise
  • Causes by a variety of problems

Sometimes a new belt may seem like the fix, but if the drive is not inspected, problems like misalignment and tensioning won’t be remedied.

Two Main Types of Belt Noise

1. Chirp

  • A series of intermittent noises
  • As belt speed increases, pitch and volume stay constant
  • Often results from misalignment (either Axial or Angular)
  • Also caused by:
    • Improper installation
    • Extremely worn ribs
    • Worn pulley bearings
    • Fluid contamination
  • More frequent in Poly Rib drives

2. Squeal

  • High-pitched noise
  • Lasts several seconds
  • Does not change pitch
  • May change in volume
  • Most common belt noise
  • May be continuous or intermittent
    • Changing with acceleration
    • Or added accessory load (A/C compressor)

New Belt?

A new fan belt can seem to resolve the noise problem and most brands now contain fiber, such as Dayco’s new Poly Rib “W Profile” belt. Once the fiber has worn off the belt and the ribs become seated in the pulley, the belt performs more aggressively.

If misalignment is not identified and remedied, the noise problem has not really been fixed.

Direct Cause of Squeal

A direct cause of squeal is slip between the belt and pulleys. This comes from:

  • Low belt tension
    • Low installation tension
    • Tension decay
    • Sidewall wear
  • High loads
    • Bearing drag
    • Accessory ready to fail
  • Under-designed drive
    • High accessory load
    • Insufficient wrap on the driven pulley
  • Belt dressing or contamination from oil or anti-freeze

Tip: Don’t Use Belt Dressing!

Whatever the noise, belt dressing won’t work! Belt dressings are not effective and will destroy the belt further.

Aftermarket belts, hoses and tensioners for your medium or heavy-duty truck

View our online selection of  Dayco replacement serpentine belts, timing belts, v belts, tensioners and pulleys. Order directly online and enjoy same day shipping on in-stock items and FREE standard shipping on orders over $250.

Articles you may also like:

5 Reasons You’ll Love the VDO RoadLog ELD

USA Made Jacks – Safe, Smart and American Made

Heavy Duty Truck Parts

RYDER Fleet Products is a BBB A+ company offering quality aftermarket truck and trailer parts, driver training material, and safety products.

Keep your fleet running smoothly with easy access to the same maintenance tested and road-proven heavy-duty aftermarket truck parts that Ryder® uses on its own fleet. With over 80 years of experience maintaining the most reliable fleet in America, Ryder knows more about parts than anyone else.

For product updates and industry resources,
Sign up to receive our e-newsletter

Information and video provided by Dayco Products, LLC.

Dayco Belts

Ryder Fleet Products, Truck Equipment & Parts, Lawrenceville, GA

1 Comment

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.