F 250 4WD HD Pickup V8-460 7.5L VIN G EFI (1997)
NOTE:
TO USE THIS PROCEDURE PROPERLY, YOU MUST...
1.
First, locate the PLANE OF IMBALANCE on the driveshaft (sweet spot) where the correction weights should be placed.
2.
After the plane of imbalance is located, the amount of WEIGHT is ADJUSTED for best results.
PLANE OF BALANCE
1.
Mark and number four (4) equally spaced (90°) points on the driveshaft tube or slip yoke as close as possible to the U-joint.
2.
Install a hose clamp at the number one (1) position.
NOTE:
SEVERELY IMBALANCED SYSTEMS MAY REQUIRE TWO (2) CLAMPS TO SHOW A RESPONSE.
3.
Drive/evaluate and record the vibration rating with the clamp at each of the four (4) marked locations.
1.
2.
3.
4.
NOTE:
NONE OF THE ABOVE POINTS MAY BE PARTICULARLY GOOD, BUT THAT DOES NOT MATTER. AT THIS TIME YOU ARE
MERELY TRYING TO FIND A POINT OR POINTS THAT TEND TO BE BETTER THAN THE REST.
4.
If one (1) of the above points is clearly better than the other three (3), evaluate and record your ratings with the clamp moved 45° either side of
that point.
+45°
-45°
5.
If Step 3 showed two (2) points that were about equal, evaluate and record your rating with the clamp moved to a point midway between these
points.
Mid-point
6.
The plane of imbalance will be located at the best point found in either Steps 3, 4 or 5. Mark this point as your reference point for the following
weight adjustment steps.
WEIGHT ADJUSTMENT
1.
A second hose clamp can be added in line with the first one.
2.
Two (2) hose clamps aligned 45° either side of the reference line will have the effect of one and one-half (1-1/2) hose clamps.
3.
A typical hose clamp barrel weighs about 14 grams (0.5 ounce). A 7 gram (0.25 ounce) lead tire weight can be placed under the clamp opposite
the barrel to cut its effect in half.
