First-Order Driveline Vibration Symptoms
The following symptoms may indicate first-order driveline vibration:
| • | The vibration is related to vehicle speed. |
| • | The vibration is torque sensitive. |
| • | A boom or moan noise is present. |
| • | The vibration occurs commonly above 72 km/h (45 mph),
but possibly at speeds as low as 48 km/h (30 mph). |
| • | The roughness or buzz vibration is felt in the seat, the floor
or the steering wheel. |
| • | The corresponding frequency on the EVA equals first-order driveline
rotation (25-60 Hz), depending on the speed of the vehicle and
the ratio of the axle. Refer to
Matching Frequency to Component RPM
in order to obtain
the rotation speed of the propeller shaft. |
