Safari Van 2WD V6-4.3L VIN X (2003)
Vibration Damper: All Technical Service Bulletins
Drivetrain - Booming Noise at Highway Speeds
Bulletin No.: 00-03-09-001A
Date: July 29, 2003
TECHNICAL
Subject:
Rolling Boom Noise Inside Vehicle (Install Pinion Nose Damper and/or New Rear Leaf Spring Dampers)
Models:
1995-2004 Chevrolet Astro Van Models
1995-2004 GMC Safari Van Models
Supercede:
This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-03-09-001 (Section 03 - Suspension).
Condition
Some owners may comment about a "boom" noise inside the vehicle while driving at speeds ranging between 97-105 km/h (60-65 mph). This condition
is most noticeable from behind the driver's seat.
Cause
The condition may result from an engine-firing harmonic, which becomes noticeable at torque converter clutch (TCC) lock-up.
Correction
A new rear leaf spring damper kit (one per spring) has been developed, to be used in conjunction with a pinion nose damper tuned to 86 Hertz (Hz), to
reduce the resultant noise level.
AFFECTED VEHICLES MAY REQUIRE THE INSTALLATION OF THE PINION NOSE DAMPER, THE SPRING DAMPERS, OR BOTH. THE
INSTALLATION OF EITHER OF THESE DAMPERS IS AT THE DISCRETION OF THE TECHNICIAN FOR BEST RESULTS. Use the following
procedures and the appropriate part number listed below.
Important:
Installation of these dampers will not totally eliminate the boom noise. The boom noise may only be reduced to a more acceptable level. There
may be other boom noises, such as body or exhaust, associated with the vehicle and this fix may either diminish or enhance the noise. These
other noises should be addressed prior to the correction for the TCC boom dampener being installed.
Pinion Nose Damper Installation Procedure
Use Damper Kit, Rr. Axle Vib., P/N 15006567, for this procedure.
