Runout Check

NOTE: The procedure for checking rotor runout and thickness is the same for the front and rear rotor. If there is a specification difference between the front and rear rotor it will be designated as such in the specifications of the following procedure.

Checking Brake Rotor For Runout:

MEASURING ROTOR
On-vehicle rotor runout is the combination of the individual runout of the hub face and the runout of the rotor. (The hub and rotor runouts are separable). To measure runout on the vehicle, remove the wheel and reinstall the lug nuts tightening the rotor to the hub. Mount Dial Indicator, Special Tool C-3339 with Mounting Adapter, Special Tool SP-1910, or equivalents on steering arm. Dial indicator plunger should contact braking surface of rotor approximately 10 mm (0.393 inches) from outer edge of rotor. Check lateral runout on both sides of rotor. Lateral runout of the rotor should not exceed 0.13 mm (0.005 inch).

Marking Rotor And Wheel Stud:

Checking Disc Brake Rotor For Runout:

Indexing Rotor And Wheel Stud:

MEASURING HUB
If lateral runout is in excess of the specification, check the lateral runout of the hub face. Before removing rotor from hub, make a chalk mark across both the rotor and one wheel stud on the high side of the runout. This will ensure that the original location of the rotor in relation to the hub can be retained. Remove rotor from hub. Thoroughly clean the front surface of the front hub. Then install Dial Indicator, Special Tool C-3339 and Mounting Adapter, Special Tool SP-1910, or equivalent on steering knuckle. Position stem so it contacts hub face near outer diameter. Care must be taken to position stem outside the stud circle but inside the chamfer on the hub face. Clean hub surface before checking. Lateral runout should not exceed 0.08 mm (0.003 inch).

- If runout exceeds this specification, the hub must be replaced.

- If lateral runout of the hub does not exceed this specification, install rotor on hub with chalk marks two wheel studs apart. Tighten nuts in the proper sequence and torque to specification. Finally, check lateral runout of rotor to see if lateral runout is now within specification.

REPAIR
If lateral runout is not within specification, install a new rotor or reface rotor, being careful to remove as little rotor material as possible from each side of rotor. Remove equal amounts from each side of rotor. Do not reduce thickness below minimum thickness marking cast into the un-machined surface of the rotor.