Manual Driveline Balancing Method

This method is used only if an EVA is not available. Be sure to verify that driveshaft and pinion flange runout are within specification. When doing this process, use a drive-on type hoist. Level the rear and front of the vehicle on the hoist using jack stands. Remove the rear wheels and replace the lug nuts to secure the rear brake (rotor or drum) and raise the vehicle on the hoist.

1. Number the driveshaft 1 through 4 in 90 degree increments.

2. Using a dial indicator, determine the low point of the driveshaft.

3. Start the balancing process by installing weight at this point.

4. Run the vehicle up to the suspected speed on the hoist. If the vibration still exists, the weight is too heavy or too light.

^ If weight is too heavy, split the weights 180 degrees from the centerline and see if the vibration is eliminated.

^ If weight is too light, position the clamps so they are 120 degrees from each other and the centerline is between them.

5. To refine this further, proceed with the following. This involves running the vehicle up to the suspect speed while on the hoist.

CAUTION
BEFORE PERFORMING THIS PROCEDURE BE SURE ALL LONG HAIR AND LOOSE CLOTHING IS TUCKED AWAY TO PREVENT POSSIBLE INJURY.

a. With another person in the vehicle, run vehicle up to suspect speed. Using a piece of chalk, lightly touch the spinning driveshaft. After you have done this, turn the engine oft. Let the vehicle coast to a stop. Do not apply the brakes or put the transmission in Park.

b. When the driveshaft and axle have stopped spinning, examine the chalk marks. The spot where the mark is the darkest is the heavy spot on the driveshaft. Place the weight 180 degrees away from this point. If you have a constant line around the driveshaft, retry the marking process, holding the chalk farther away.

c. Rerun the vehicle with the clamp in this position, noting if the vibration has been eliminated. If not, place the clamp on the light spot and retest at the suspect speed. If this does not improve or eliminate the vibration, move the clamp to different positions around the driveshaft making note of any improvements.

d. If no improvement is noticed, another clamp may be needed. Start by separating the clamps 180 degrees from the heavy spot and start moving them closer, then further away from the heavy spot, noting any change.

e. Once you have found the best position, put the wheels back on the vehicle and drive it on the street. A slight vibration noticed on the hoist may be eliminated by loading the axle with the weight of the vehicle.

NOTE
BE SURE TO REFER TO THE WORKSHOP MANUAL FOR DIFFERENT PHASING OF THE CLAMPS. THESE CLAMPS ALSO COME IN DIFFERENT WEIGHTS. THIS ALSO SHOULD BE REVIEWED FOR BEST RESULTS.