Rear Disc Rotor: Inspection

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Check the rear wheel bearing play and axle hub runout before inspecting the disc rotor runout. < Refer to INSPECTION , Rear Hub Unit Bearing. >
Secure the disc rotor by tightening the five wheel nuts.
Set a dial gauge 10 mm (0.39 in) inward from the disc rotor outer circumference. Rotate the disc rotor to check runout. If the disc rotor runout exceeds the limit, resurface the disc rotor. After grinding, check the thickness of the disc rotor according to the procedure in step 4).

Fig 1: Measuring Rear Wheel Bearing Play And Axle Hub Runout Using Dial Gauge
Courtesy of SUBARU OF AMERICA, INC.

Disc rotor runout limit:

0.05 mm (0.0020 in)
Set a micrometer 10 mm (0.39 in) inward from the disc rotor outer perimeter, and then measure the disc rotor thickness. If the thickness A of the disc rotor exceeds the service limit, replace with a new disc rotor.

Fig 2: Identifying Disc Rotor Thickness And Threads
Courtesy of SUBARU OF AMERICA, INC.

Standard		Limit	Disc rotor diameter
Disc rotor thickness A mm (in)	10 (0.39)	8.5 (0.335)	286 (11.26)