Note: To measure front wheel runout, slowly rotate the wheel by hand from the opposite side.
1. Raise the vehicle and place safety supports in appropriate places.
2. Make sure there are no dents or deformations on the wheel rims.
3. Mount the micrometer fixture as shown in the figure and, rotating the wheel, measure the axial runout of the disc.
Standard for axial runout of front and rear wheel discs.
- Steel discs: 0-1.0 mm.
- Aluminum wheels: 0-0.7 mm.
- Working range limit: 2.0 mm.
4. Move the fixture with the micrometer to the position shown in the figure and measure the radial runout.
Standard radial runout of front and rear wheel disks.
- Steel discs: 0-1.0 mm.
- Aluminum wheels: 0-0.7 mm.
- Working range limit: 1.5 mm.
5. If the wheel runout is out of specification, check the wheel bearing play and ensure that the mating surfaces of the brake disc and the inner surface of the wheel are clean.
6. If the bearing clearance is within the permissible limits and the disc runout is beyond the limit, replace the disc.