Troubleshooting Belt Failure - Spring/Summer Car Care


	Solutions


	Catalogs


	Part Interchanges


	Industrial Power Transmission


	Industrial Fluid Power

Automotive Aftermarket


	Idea Submission Form


	Promotions & Incentives


	Solution Kits


	Catalogs


	Part Locator & Interchange


	Imports


	Parts Store Locators


	Tool Bucks/Gates Exchange Program


	Training

Cars & Light Trucks


	Belts


	Belt Tensioners/Pulleys


	Automotive Hose


	Hydraulics


	Transmission Oil Cooler Assemblies


	Water Pumps


	Tools


	Power Steering


	Clamps


	techTIPS

Consumer Maintenance


	Fall/Winter Car Care

Spring/Summer Car Care


	Troubleshooting Belt Failure


	Coolant Hoses


	Tensioners


	Timing Belts


	Serpentine Belts


	Fleet & Heavy-Duty Aftermarket


	Snowmobile & Sport


	Auto OE


	Gates Brand Protection


	News


	Sitemap

Content Tools

Feedback Form

Print Format

Troubleshoot Potential Belt Failure

Breakdowns never happen at a convenient time

When a serpentine belt breaks, a variety of critical engine components stop working. This can include your alternator, water pump, power steering and air conditioning. Use this easy-to-follow chart to troubleshoot belts for potential problems and to avoid roadside failures due to a bad belt. Always replace your worn belts with high-quality Gates belts for long-lasting performance.

WARNING ! Before any belt inspection, make sure the engine is off and disconnect the battery to avoid accidental starting.


APPEARANCE: Each side of belt appears shiny or glazed. In advanced stages, fabric becomes exposed. CAUSE: When in motion, the belt makes contact with an object in its path such as a flange or bolt. This may be caused by improper belt tension or pully bearing size. SOLUTION: Replace belt and remove the foreign object or, if it can’t be removed, ensure that contact is avoided. Check the automatic belt tensioner and ensure proper belt tension.	APPEARANCE: Pieces or chunks of rubber material have broken off from the belt. When chunk-out has occurred, a belt can fail at any moment. CAUSE: Chunk-out can happen when several cracks in one area move parallel to the cord line. Heat, age and stress are the primary contributors. SOLUTION: Replace the belt immediately with a Gates Micro-V® belt. Gates belts are designed for greater flexibility and heat tolerance in today’s smaller engine compartments.

APPEARANCE: Belt material is sheared off from the ribs and builds up in the belt grooves. CAUSE: There are a number of causes, including lack of tension, misalignment, worn pulleys or a combination of these factors. Pilling is found most frequently in diesel engines, but is not isolated to them. SOLUTION: When pilling leads to belt noise or excess vibration, the belt should be replaced. Accessory brake pulleys should be checked for material buildup between groves. Replace if necessary.	APPEARANCE: Belt shows damage to the side with the possibility of breaks in the tensile cord or jaggededged ribs. A thumping or grinding noise may also be heard when running. CAUSE: A foreign object—such as a small pebble—in the pulley can cause uneven wear and cut into the belt. SOLUTION: Replace belt and inspect pulley for foreign objects or damage. Replace pulley if necessary.

APPEARANCE: A belt rib begins separating from the joined strands. If left unattended, the cover will often separate, causing the belt to unravel. CAUSE: Improper belt installation is a common cause of premature failure. One of the outer-most belt ribs is placed outside the pulley groove, causing a belt rib to run without a supporting or aligning pulley groove. SOLUTION: The belt’s life has been severely limited and should be replaced immediately. Ensure all ribs of the replacement belt fit into the pulley grooves. Run the engine. Then, with the engine off and battery disconnected, inspect the belt for proper installation.	APPEARANCE: Small, yet visible cracks along the length of a rib or ribs. CAUSE: With continuous exposure to high temperatures, the stress of bending around the pulley leads to cracking. Cracks begin on the ribs and grow into the cord line. As a rule, if three or more cracks appear in a three-inch section of a belt, eighty percent of the life is gone and the belt should be replaced. SOLUTION: Replace with Gates Micro-V® belt, which is engineered to withstand higher temperatures and to resist cracking. Check tensioner pulley and idler pulley for bearing wear. Replace if necessary.

APPEARANCE: Sidewalls of the belt may appear glazed or the edge-cord may become frayed and ribs removed. A noticeable noise may result. In severe cases, the belt can jump off the pulley. CAUSE: Pulley misalignment can be caused by two conditions (see below). Misalignment forces the belt to kink or twist while running, causing premature wear. SOLUTION: Replace the belt and make sure to realign the pulleys. Also check to make sure the pulleys, pulley brackets and shafts are not bent or broken.	APPEARANCE: Small pinholes are visible on the backside of the belt. Bumps may be visible and fabric around the holes can be frayed. CAUSE: Rock, gravel or sand is wedged between the belt grooves and pulley ridges. SOLUTION: The belt needs to be replaced to avoid tensile cord separation and possible roadside failure. Replace with a Gates Micro-V ® belt because it is precision ground for a better pulley fit, unlike common knife-cut belts.

When to Replace Your Belts

Vehicle Age In Years –

Gates recommends replacing serpentine belts on cars four years old or older. This graph illustrates why. Notice how the incidence of belt failure increases dramatically after the fourth year of operation.

Automatic Tensioners – Proper Tension is Critical

When an automatic belt tensioner’s internal components wear or fail, it can dramatically reduce the life of a belt. Therefore, inspect automatic tensioners carefully for symptoms such as cracked arms, excessive vibration during idle speeds, looseness, grease leaking from bearings, noise (clatter or rattling) and sticking or seized operation. These can all be signs that a tensioner needs replacing.

Check the Idler Pulleys, Too

Idler pulleys are susceptible to damage and wear and should be inspected regularly, too, especially before installing a new belt. Nylon pulleys are especially vulnerable to wear problems under heavy loads that occur at engine idle speeds when all accessories are operating (such as stop-and-go conditions in the heat of summer). Pulleys can also fail due to loss of bearing lubrication which contributes to belt wear. Gates offers a full line of premium automatic belt tensioners and idler pulleys engineered to look, fit and operate like original equipment. To avoid trouble down the road, always ask your installer for Gates replacement products.