Steering System Symptom Definitions: Moan
Moan is the general structure-borne noise of the steering system. Moan is typically in the frequency range of 100 Hz to 600 Hz. Moan is primarily transmitted to the driver via body structure, through the pump mount, engine mounts, power steering lines and brackets. For problem vehicles, moan is a loud humming noise, often present when the wheel is turned and the system is loaded. It may change in frequency with rpm and if the system is loaded or unloaded.