Sierra 1500 2WD V6-4.3L (2008)
Exhaust Pipe/Muffler Hanger: All Technical Service Bulletins
Exhaust System - Moan/Vibration Noise At Low RPM
TECHNICAL
Bulletin No.: 02-06-05-003J
Date: February 16, 2011
Subject: Exhaust Moan/Vibration Noise (Install Exhaust System Flex Pipe Kit)
Models:
1999-2007 Chevrolet Silverado 1500 Series Extended Cab or Regular Cab/Long or Short Box Pickups (Classic)
2007-2011 Chevrolet Silverado 1500 Series Extended Cab or Regular Cab/Long or Short/Standard Box Pickups (New Body Style)
1999-2007 GMC Sierra 1500 Series Extended Cab or Regular Cab/Long or Short Box Pickups (Classic)
2007-2011 GMC Sierra 1500 Series Extended Cab or Regular Cab/Long or Short/Standard Box Pickups (New Body Style)
Equipped with 4.3L Engine (VINs W, X - RPOs L35, LU3) and Automatic Transmission (RPO M30)
New Body Style 2007-2011 Fort Wayne (VIN Z - RPO FWI) Built Vehicles Before January 2011 and All Silao (VIN G - RPO MSL) Built Vehicles
Supercede:
This bulletin is being revised to add the 2011 model year and vehicle build information. Please discard Corporate Bulletin Number 02-06-05-003I
(Section 06 - Engine/Propulsion System).
Condition
Some customers may comment on a moan or vibration noise at low vehicle speeds 40-64 km (25-40 mph) or between 900-1700 RPM under load.
Cause
Exhaust system resonance may be transmitted through the powertrain mounts into the body causing this condition.
Correction
Caution
Personal injury or burns may occur when working on a hot exhaust system, let the exhaust system cool off prior to performing the repair.
An exhaust system flex pipe kit is available to correct this condition. If diagnosis leads to this condition, install the applicable exhaust system flex pipe
kit listed below using the following procedure. Refer to the Parts Information for kit applications and usage.
Important
This fix and the kit part numbers are specific to vehicle frame type. A Level 3 frame was introduced interim 2000 model year (approximately
January 2000). With a Level 3 frame, the transmission crossmember was moved forward of its previous location. Pre-Level 3 frames will
require the installation of additional components to correct the condition.
1999-2000 4WD Models Built Prior to 1/20/2000 and All 2000-2011 2WD and 4WD Models Built After 1/2000 (Fort Wayne Built Vehicles
Before 1/2011 and All Silao Built Vehicles) (Except Regular Cab Short Bed Vehicles)
These models require the installation of a flex coupling. The flex coupling has adapter sleeves for the installation of U-bolt clamps. This procedure uses
the U-bolt clamps, but the preferred installation method is to weld the flex coupler to the exhaust pipe.
1. Raise the vehicle.
2. Locate the first available straight section of pipe rearward of the mid-joint flange and forward of the muffler assembly.
3. Measure approximately 228 mm (9 in) on the straight pipe and mark.
4. Using a suitable cutting tool, cut out the marked section of the pipe and remove.
5. Remove any burrs, if necessary, before installing the flex coupler pipe.
