G8 V6-3.6L (2008)
Technical Service Bulletin # 10-03-09-001A
Date: 100223
Vehicle - Shake/Vibration/Noise At Highway Speeds
TECHNICAL
Bulletin No.: 10-03-09-001A
Date: February 22, 2010
Subject: Shake/Vibration in Steering Wheel, Boom/Moan Noise at Highway Speeds on Smooth Roads (Replace Engine Mounts, Propshaft, Balance
Wheel and Tire Assemblies or Correct Brake Rotor Runout)
Models:
2008-2009 Pontiac G8
Attention:
It is requested that you become familiar with all the various concerns before attempting diagnosis or repair. In ALL cases, a propshaft is the last
component replacement that should be attempted. Replacement propshafts are only available on an exchange basis directly through GM Brand Quality
(except 2008 MY 3.6L V6 models). If it is determined that a propshaft replacement is required, you will be expected to furnish written data to GM Brand
Quality validating diagnostics of the other possible components.
Supercede:
This bulletin is being revised to update the contact information under the Propshaft Exchange section. Please discard Corporate Bulletin Number
10-03-09-001 (Section 03 - Suspension).
Condition
Some customers may comment on shaking/vibration in the steering wheel/driver seat and/or a boom/moan noise while driving at highway speeds
(typically between 55-70 mph (88-112 km/h) on smooth roads.
Steering Wheel Vibration
Vibrations in the steering wheel may also be accompanied by vibration in the body and/or seat but may be more obvious to the driver due to contact with
the steering wheel. When the steering wheel is held loosely on smooth roads, driving straight ahead, slight steering wheel oscillation may be visible.
Boom/Moan Noise
A "boom" or "moan" noise is a very low frequency sound that phases in and out. The customer may describe the noise as a loud continuous bass note
produced by the radio that comes and goes. This type of noise may be mistaken for the feeling of objectionable pressure in the passenger compartment.
Additionally, noises of this frequency range may make hearing other sounds, such as normal conversation, seem distorted. This noise may accompany
vibration felt in the body, seat or steering wheel.
Cause
The vehicle may be sensitive to the balance of various rotating mass assemblies. This may include the following possible sources:
-
Wheel and Tire Assembly Balance and Road Force Variation
-
Tire and Wheel Diagnosis
-
Measuring Wheel Runout and Assembly Radial Force Variation
-
Excessive Brake Rotor Runout or Imbalance
-
Active Fuel Management (AFM)
-
Propshaft Runout or Imbalance
Disclaimer
