Pep Boys Diagnosing Engine Belt Noise Video

Here’s a noisy Chrysler 300 with a locked-center tensioned accessory drive. In order to determine if the noise is a chip or a squeal one method is to spray the rib side with water. If the noise gets louder its technically a squeal and therefore a tension issue rather than misalignment. First disconnect the battery for safety sake. Since this is a locked-center tension drive the adjustable idler pulley should be inspected first. Spin it to check for lock-up, binding or a gravely sound. If it free-wheels the grease is gone. Also check for free-rock. A little is ok but too much means the pulley should be replaced. Next inspect any remaining pulleys in the drive and replace if defective. If all the pulleys check out or if defective ones have been replaced, the next step is to put a new Dayco belt on the drive and tension it correctly. The initial tension should be set according to the recommendations of Dayco belt engineers. This six rib belt should be tensioned to 35 pounds per rib or 210 pounds. Use a tension gauge designed for multi-rib belts to test the tension. This first reading is 120 pounds. Continue tensioning and gauging until the correct tension is reached. This belt is now tensioned to the recommended tension of 210 pounds. Remember the number. ALERT… Pep Boys warn… DO NOT SKIP THE NEXT STEP. It’s usually skipped which is the cause of most tensioning problems with serpentine belts on locked-center drives. Start the engine and run for three to five minutes

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