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How to Quiet a Noisy Drive Belt

a drive belt

The drive belt is used to drive the accessories mounted on the front of the engine, such as the alternator, power steering pump and water pump. The belt itself is driven off the crankshaft pulley. There are a number of lubricants for sale which claim to quiet a noisy drive belt, but the only effective way to silence the squealing is to adjust the drive belt to specification.

  • Note: If the vehicle is equipped with a serpentine belt, it is not possible to adjust it. In that case, a squealing belt indicates a failed tensioner or misaligned pulley system, which will require repair.

Materials Needed

  • Free repair manuals - Autozone provides free online repair manuals for certain makes and models
  • Protective gloves
  • Pry bar (as needed)
  • Safety glasses
  • Wrench or ratchet and sockets of the appropriate size

Method 1 of 2: Adjusting a belt with an adjuster pulley

point of adjustment via a pulley

Step 1: Locate the point of adjustment. Drive belt adjustment is performed via either a adjuster pulley or accessory pivot and adjuster bolts.

Either design will be located on the front of engine in the drive belt area. In this case you are looking for the adjuster pulley.

loosening the adjuster pulley nut

Step 2: Loosen the adjustment pulley locking fastener. Loosen the locking fastener on the face of the adjustment pulley by turning it counterclockwise with the appropriate sized ratchet or wrench.

  • Note: Do not remove the fastener, only loosen it.

tightening the adjustment bolt

Step 3: Tighten the adjustment fastener. Tighten the adjustment fastener on top of the pulley by turning it clockwise with a ratchet or wrench.

checking belt deflection

Step 4: Check the belt deflection. Check that the belt has proper tension by pushing down on the longest section of the belt. The belt should have about ½” of deflection if the belt is properly tensioned.

tightening down the pulley locking fastener

Step 5: Tighten down the pulley locking fastener. Once the proper belt tension has been achieved, tighten down the adjustment pulley locking fastener by turning it clockwise with a ratchet or wrench.

Method 2 of 2: Adjusting a belt with an accessory pivot

point of adjustment via an accessory pivot and adjuster bolt

Step 1: Locate the point of adjustment. Drive belt adjustment is performed via either a adjuster pulley or accessory pivot and adjuster bolts.

Either design will be located on the front of engine in the drive belt area. In this case you are looking for the accessory pivot.

loosening the adjustment bracket bolt

Step 2: Loosen the adjustment bracket fasteners. Loosen the adjustment bracket fasteners by turning them counterclockwise using a ratchet or wrench.

  • Note: Do not remove the fasteners.

moving the belt driven accessory

Step 3: Move the belt drive accessory. Using a pry bar, pry the belt drive accessory (whether it be the alternator, power steering pump, etc.) until the belt is tight.

moving the belt driven accessory

Step 4: Tighten down the adjustment bracket fasteners. Tighten down the adjustment bracket fasteners while still applying tension to the belt driven accessory.

belt deflection

Step 5: Check the belt deflection. Check that the belt has proper tension by pushing down on the longest section of the belt. The belt should have about ½” of deflection if the belt is properly tensioned.

That’s how you properly quite a noisy belt. If this seems like something you’d rather leave to a professional, the team at YourMechanic offers expert belt adjustment and repair services.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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