Noise, Vibration and Harshness has been dramatically improved in recent developments in all vehicle segments. The high competition between manufacturers has forced continuous reductions in overall noise levels of automotive vehicles in every market segment. The attention of NVH engineers now is to reduce noise contribution on each system and their interactions. The interaction between Powertrain and Driveline systems in a rear wheel drive vehicle development has gained even more attention regarding perceived noise. This paper presents the steps taken to identify and characterize a noise peak related to Powertrain and Driveline interaction on a pickup. The referred vehicle presented vibration associated with a rumble noise on the cockpit perceived near top speed. The problem solving process has combined vehicle measurements on road and chassis dyno, and modal tests. Each Measurement step is shown and analysis of each test is discussed. The Powertrain and Driveline systems coupled response made the problem identification rather difficult, but problem identification is presented and discussed, including proposals of possible solutions. Some advanced techniques and other possible approaches to identify this kind of problem in similar vehicles are also discussed.
