Brake Rotor/Disc: Specifications

GM brake systems are identified by Regular Production Option (RPO) codes. For further information on RPO codes see Application and ID.

	RPO JB5, JD5, JB6, JD6*	RPO JB7, JD7*	RPO JB8*	RPO JF9*
Nominal Thickness	1.25 Inch (in)	1.26 Inch (in)	1.5 Inch (in)	1.54 Inch (in)
Minimum Refinish Thickness	1.23 Inch (in)	1.23 Inch (in)	1.48 Inch (in)	1.48 Inch (in)
Discard Thickness	1.215 Inch (in)	1.215 Inch (in)	1.465 Inch (in)	1.465 Inch (in)
Thickness Variation (parallelism)	0.0005 Inch (in)	0.0005 Inch (in)	0.0005 Inch (in)	0.0005 Inch (in)
Run Out (TIR)	0.004 Inch (in)	0.004 Inch (in)	0.004 Inch (in)	0.004 Inch (in)