Drivetrain Noise and Vibration Troubleshooting 2001-01-2809

Conducting effective drivetrain NVH (Noise, Vibration and Harshness) troubleshooting is difficult because its execution requires commanding knowledge and experience on complicated vehicle system interactions. This is especially true for commercial vehicles due to the wide variety of available powertrain and chassis configurations and broad spectrum of vehicle applications. Furthermore, access to revenue producing commercial vehicles is often limited. Problem solving must be carried out within a tight schedule. Under these circumstances, a practical drivetrain NVH troubleshooting guide will come in handy. The objective of this paper is to document the “know-how” we have learned. Subjects covered in the discussions are underlying physics, problem diagnosis, solutions, and problem avoidance. The problem solving methodology and solutions for various powertrain NVH problems are exemplified by six case studies: Powertrain Torsional Vibration, Powerpack System Bending Vibration, Neutral Idle Gear Rattle, Coasting Gear Rattle, Gear Noise, and Transmission Shift Lever Jump-out.