Driveshaft Runout and Balancing

Driveshaft Runout and Balancing

Special Tool(s):

1. Inspect the driveshaft for wear or damage. If there are any worn or damaged components, install a new driveshaft.
2. Using the special tool, measure the runout at the front, the center and the rear of the driveshaft.





3. If the runout measurements are within specifications, proceed to Step 12.
4. If the runout measurements exceed the specifications at the front or the center of the driveshaft, install a new driveshaft.
5. If the runout measurement exceeds the specifications at the rear of the driveshaft, mark the rear runout high point on the driveshaft.
6. Scribe alignment marks on the driveshaft flange and the rear axle pinion flange.
7. Remove the driveshaft flange bolts from the rear axle pinion flange, then disconnect the driveshaft from the rear axle pinion flange and rotate the driveshaft 180 degrees.

8. WARNING: Always install new driveshaft flange bolts whenever the driveshaft flange bolts are removed.

Connect the driveshaft to the rear axle pinion flange, then install new driveshaft flange bolts.
^ Tighten to 25 Nm (18 ft. lbs.).
9. Using the special tool, measure the runout at the rear of the driveshaft.
10. If the runout measurement still exceeds the specification at the rear, mark the rear runout high point on the driveshaft.

11. NOTE: Excessive driveshaft runout may originate in the driveshaft itself or in the rear axle pinion flange.

Compare the 2 high points.
^ If the marks are within 25 mm (1 inch), install a new driveshaft.
^ If the marks are not within 25 mm (1 inch), balance the driveshaft. Proceed to the next step.

12. WARNING: Keep hands away from the balance weights while the driveshaft is rotating.

With the transmission in gear, run the vehicle with the driveshaft rotating.
^ Record the baseline speed with the transmission in gear.
^ Increase the vehicle speed to the maximum vibration level.
^ Record the speed of the vibration as baseline.

13. WARNING: Keep hands away from the balance weights while the driveshaft is rotating.

Have an assistant contact the driveshaft with a marker in the rear, middle and front end to indicate heavy spots.





14. WARNING: Keep hands away from the balance weights while the driveshaft is rotating.

To balance the driveshaft, install 2 screw-type hose clamps on the driveshaft and rotate them at 90 degree intervals. Check the vibration for each position and place the screws at the position that produces the least vibration.
15. Run the vehicle at the baseline speed.
16. If the vibration is still evident, rotate the clamps away from each other until the driveshaft is balanced.