Econoline E350 1 Ton V8-5.4L Prop SOHC VIN Z (1998)
The EVA allows for a systematic collection of information that is necessary to accurately diagnose and repair NVH problems. For the best results, carry
out the test as follows:
a.
Test drive the vehicle with the vibration sensor
inside the vehicle.
b.
Place the sensor in the vehicle according to feel.
-
If the condition is felt through the steering
wheel, the source is most likely in the front of
the vehicle.
-
A vibration that is felt in the seat or floor only
will most likely be found in the driveline,
drive axle or rear wheels and tires.
c.
Record the readings. Also note when the condition begins when it reaches maximum intensity. and if it tends to diminish above/below a certain
speed.
-
Frequencies should be read in the "avg" mode.
-
Frequencies have a range of plus or minus 2. A reading of 10 Hz can be displayed as an 8 Hz through 12 Hz.
d.
Determine what the normal frequency is for the vehicle at a specified speed. Multiply the rear axle ratio by the Hz (1 Hz per every 5 mph).
Example: A vehicle travelling 50 mph with a 3.08 rear axle ratio, the acceptable amount of Hz for the vehicle at that speed would be 10 (1 Hz per
every 5 mph) X 3.08 (rear axle ratio) = 30.8 Hz.
e.
Place the vibration sensor on or near the suspect area outside the vehicle.
f.
Continue the road test, driving the vehicle at the speed the symptom occurs, and take another reading.