Engine - Accessory Drive Squeak

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 99-06-01-007

Date: May, 1999

TECHNICAL

Subject:
Accessory Drive Squeak
(Replace Idler Pulley)

Models:
1997-99 Chevrolet Corvette
1998-99 Chevrolet Camaro
1998-99 Pontiac Firebird
with 5.7 L Engine (VIN G - RPO LS1)

Condition

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.

Cause

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.

Correction





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.

Important:

^ 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.

Tighten

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

Parts Information

Part Number Description

12564401 Idler Pulley Assembly

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor 0peration Description Labor Time

Pulley Assembly,
J0690 Serpentine Belt 0.3 hr
Idler - Replace