LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2012 >> Explorer Base, 3.5 8, AWD, 6F50 >> Repair and Diagnosis >> External Pages >> Different car >> Section 30 (Noise, Vibration & Harshness) >> Diagnosis And Testing >> Noise, Vibration and Harshness (NVH) >> Relationship of Vibration Frequency to Order of Vibration

Relationship of Vibration Frequency to Order of Vibration

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

After carrying out the road test as described in this article, the vibration was determined to be either vehicle-speed related or engine-speed related. That determination will identify the vibration frequency calculations that should be done.

Vibration Type Calculate
Vehicle-speed related Tire-speed vibration frequency Driveshaft-speed vibration frequency
Engine-speed related Engine vibration frequency Engine accessory vibration frequency Engine firing vibration frequency

In calculating and using frequency readings it is important to remember the direct relationship between Hz and RPM. One Hz is equal to 60 RPM. This is easy to remember. Think of Hz as cycles per second. There are 60 seconds in a minute, therefore multiply the Hz reading by 60 to get RPM. Conversely, divide RPM by 60 to get Hz.

Use the Frequency and RPM Calculations Worksheet to calculate system/component frequencies. The worksheet provides the necessary steps to determine each system/component group frequency.