Problem: Accurately determining wheel drag during diagnosis
Cause: Judging the amount of drag by rotating the tire/wheel assembly by hand is not always an accurate method of determining wheel drag
Solution: When diagnosing the cause of a wheel drag check it is important to be able to accurately determine if the results of a test step impacted the amount of wheel drag. Some drag conditions result in only a slight drag being created making diagnosis more difficult.
1. Duplicate the drag condition
2. Adjust the torque wrench to a midway setting such as 30 (Figure 53.1)
3. Position a wheel stud to the three o’clock position as shown in Figure 53.2
4. Place the torque wrench on the lug nut at the three o’clock position.
5. Attempt to rotate the tire/wheel assembly while noting whether or not the torque wrench clicks. If the torque wrench clicks before the wheel rotates go to next step. If the torque wrench does not click before the wheel rotates go to step 7.
6. Torque wrench clicks before wheel rotates – adjust the torque wrench to a higher setting and attempt to rotate the wheel. A good rule of thumb is to increase it by 10. Repeat this step until the wheel just rotates when the torque wrench clicks.
7. Wheel rotates before torque wrench clicks – adjust the torque wrench down and attempt to rotate the wheel. A good rule of thumb is to decrease it by 10. Repeat this step until the wheel just rotates when the torque wrench clicks.
TIP: When diagnosing a one wheel drag condition measure the wheel drag on the opposite (non-dragging) wheel to use as a comparison. When performing diagnostic steps to determine the cause of a wheel drag use the opposite wheel’s drag measurement to determine if dragging wheel is completely releasing. See page 94 for one wheel drag diagnosis.