Design of Experiments Application (DOE) to Prevent Mechanical Noise in Power Rack & Pinion Steering Systems

Nowadays, ever market vehicle change affects body, suspension & steering gear systems. The purpose of this report is to quantify the methodology for evaluating and improving rattle mechanical noises in power rack & pinion steering systems. It is very important the correct process be used to adjust and approve the power steering gears in order to prevent the knock noise issue on services (warranty).

This report describes how Visteon's Engineering makes efforts to achieve a reduction in warranty issues due to mechanical noise in the power steering gear, which affects its performance. We refer to this mechanical noise as “Knocking Noise” which derives from the gearing (meshing) adjustment loss.

This experiment, supported by the Six Sigma methodology, led to new knowledge on how to improve the method of meshing adjust and test approval in process through of Design of Experiments (DOE).

The DOE's results were correlated with the meshing load test machine and confirmed the steering efforts results by the durability tests and racetrack tests such as “Cobblestone and Full circle”.