GM Service Manual Online
For 1990-2009 cars only

Special Tools

J-8001 Dial Indicator Set

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  2. Mark the location of the wheels to the wheel studs and mark the specific vehicle position on each tire and wheel - LF, LR, RF, RR.
  3. Remove the tire and wheel assemblies from the vehicle. Refer to Tire and Wheel Removal and Installation.
  4. Remove the brake rotors from the vehicle. Clean the mounting surfaces of the brake rotors and the hub/axle flanges of any loose debris, rust, and corrosion.

  5. Object Number: 205276  Size: SH
  6. Position the J-8001 Indicator , or equivalent, on the machined surface of the wheel hub/axle flange outside of the wheel studs.
  7. Rotate the hub one complete revolution in order to find the low spot.
  8. Set the J-8001 Indicator , or equivalent, to zero at the low spot.
  9. Rotate the hub one more complete revolution and measure the total amount of wheel hub/axle flange runout.
  10. Specification

        • The maximum runout of the front wheel hub is 0.03 mm (0.00118 in).
        • The maximum runout of the independent rear suspension wheel hub is 0.07 mm (0.00275 in).
        • The maximum runout of the twist beam rear suspension wheel hub is 0.06 mm (0.00236 in).
  11. If the runout of the wheel hub/axle flange IS within specification and the vehicle is equipped with wheel studs, proceed to step 13.
  12. If the runout of the wheel hub/axle flange is marginal, the wheel hub may or may not be the source of the disturbance.
  13. If the runout of the wheel hub/axle flange is excessive, replace the wheel hub/axle flange. Measure the runout of the new wheel hub/axle flange.

  14. Object Number: 205279  Size: SH
  15. Position the J-8001 Indicator , or equivalent, in order to contact the wheel mounting studs.
  16. Measure the stud runout as close to the flange as possible.

  17. Turn the hub one complete revolution to register on each of the wheel studs.
  18. Zero the J-8001 Indicator , or equivalent, on the lowest stud.
  19. Rotate the hub one more complete revolution and measure the total amount of wheel stud - stud circle - runout.
  20. Specification - Guideline
    Wheel stud runout tolerance guideline: 0.254 mm (0.010 in)

  21. If the runout of the wheel studs - stud circle - is marginal, the wheel studs may or may not be contributing to the disturbance.
  22. If the runout of the wheel studs - stud circle - is excessive, replace the wheel studs as necessary. Measure the runout of the new wheel studs.