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1997 - 1999 Corvette: Service Bulletin: Accessory Drive Squeak (Replace Idler Pulley)

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Subject: Technical - Accessory Drive Squeak (Replace Idler Pulley)
Source: Chevrolet Service Bulletin
Number: 99-06-01-007
1997 - 1999 Chevrolet Corvette
1998 - 1999 Chevrolet Camaro
1998 - 1999 Pontiac Firebird
with 5.7 L Engine (VIN G - RPO LS1)


Some customers may comment on a squeak noise coming from the engine or accessory drive while the engine is running . This squeak may vary in volume and may be heard inside the vehicle with the windows up and the radio on.


The idler pulley dust shield may distort during assembly due to torquing of the mounting bolt. This distortion may cause the idler pulley dust shield to contact the bearing race and the pulley resulting in the squeak noise.


A new idler pulley assembly is available with a thicker dust shield to prevent the distortion of the dust shield. The previous dust shield thickness is 0.61 mm. The new dust shield thickness is 1.37 mm.


  • Do not over-torque the mounting bolt or the condition may reoccur.
    Do not use pneumatic or electric tools for installation of the idler pulley assembly.


Torque the idler pulley bolt to 50 N·m (37 lb ft).

Parts Information

Part Number



Idler Pulley Assembly


GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


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1997 - 1999 Corvette: Service Bulletin: Accessory Drive Squeak (Replace Idler Pulley)

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