GM Service Manual Online
For 1990-2009 cars only

The universal joint angle can be measured using this method with the vehicle on a hoist, over an inspection pit, or on the ground.

The suspension travel will not affect the driveline angles.

Tools Required

J 23498-A Driveshaft Inclinometer

  1. Take a measurement at the universal joint bearing cap mounted in the rear propeller shaft yoke:
  2. • Rotate the shaft until the cap is facing straight down.
    • Place the J 23498-A on the cap.
    • Center the bubble in the J 23498-A sight glass.
    • Record the measurement.
  3. Take a measurement at the universal joint bearing cap mounted in the front propeller shaft yoke:
  4. • Rotate the shaft 90 degrees.
    • Place the J 23498-A on the cap.
    • Center the bubble in the sight glass.
    • Record the measurement.
  5. Determine the universal joint angle by subtracting the smaller measurement from the larger. (The angle is actually the angle between the front (transmission) and rear (differential) propeller shaft half centerlines.)
  6. Maximum Angle
    Maximum universal joint angle is 0.75 degrees.

  7. Adjust the universal joint angle as necessary:
  8. • In order to increase the angle, add shims between the insulator and the mounting bracket.
    • In order to decrease the angle, add shims between the mounting bracket and the underbody.