Driveshaft Runout and Balancing

Driveshaft Runout and Balancing





Special Tool(s)
1. Remove the rear tires.
^ Install the lug nuts to retain the brake drums or brake disc.





2. Check the rear driveshaft attachment. If there are any worn parts, new parts need to be installed.





3. Using the special tool, measure the runout at the front, the center, and the rear of the driveshaft.
4. If the runout measurements are within specifications, go to Step 13.
5. If the runout measurements exceed the specifications at the front or the center, then install a new driveshaft.
6. If the runout measurement exceeds the specifications at the rear, mark the rear runout high point on the driveshaft.
7. Scribe alignment marks on the driveshaft and the axle pinion flange.
8. Index the driveshaft.





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. If the runout measurement is within specifications, go to Step 13.

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

Compare the two high points marked in Steps 6 and 10.
^ If the marks are within 25 mm (1 inch), then install a new driveshaft.
^ If the marks are not within 25 mm (1 inch), balance the driveshaft. Go to Step 13.

13. CAUTION: To prevent overheating, do not run the vehicle on the hoist for an extended period of time.

Record baseline speed with the transmission in gear.
^ Increase the vehicle speed to the maximum vibration level.
^ Record the speed of the vibration as a baseline.

14. WARNING: Keep hands away from the balance weights while the driveshaft is rotating. Failure to follow these instructions may result in personal injury.

With the transmission in gear, run the vehicle with the driveshaft rotating 97-113 km/h (60-70 mph).

15. WARNING: Keep hands away from the balance weights while the driveshaft is rotating. Failure to follow these instructions may result in personal injury.

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





16. WARNING: Keep hands away from the balance weights while the driveshaft is rotating. Failure to follow these instructions may result in personal injury.

To balance the driveshaft, install two screw-type hose clamps on the driveshaft and rotate them in 90 degree intervals. Check the vibration for each position and place the screws at the position that produces the least vibration.
17. Run the vehicle at the baseline speed.





18. If the vibration is still evident, rotate the clamps away from each other until the driveshaft is balanced.