Rear Disc Rotor: Inspection

Check rear wheel bearing play and axial hub runout before disc rotor runout limit inspection. <Ref. toINSPECTION , Rear Hub Unit Bearing.>
Secure the disc rotor by tightening five wheel nuts.
Set a dial gauge 10 mm (0.39 in) inward of the rotor outer perimeter. Turn the disc rotor to check runout. If the disc rotor runout exceeds specified value, replace with a new disc rotor.

Fig 1: Measuring Disc Rotor Runout
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 of the rotor outer perimeter, and then measure the disc rotor thickness. If the thickness of disc rotor exceeds the service limit, replace with a new disc rotor.

Fig 2: View Of Disc Rotor

Courtesy of SUBARU OF AMERICA, INC.

DISC ROTOR THICKNESS SPECIFICATIONS

Standard value			Limit	Disc outer dia.
Disc rotor thickness A mm (in)	Solid disc	10 (0.39)	8.5 (0.335)	274 (10.79)
Disc rotor thickness A mm (in)	Ventilated disc	18 (0.71)	16 (0.63)	290 (11.42)