GM Service Manual Online
For 1990-2009 cars only

Application

Specification

Metric

English

JM3 (Front)

  • Rotor Discard Thickness *

24.51 mm

0.965 in

  • Rotor Minimum Allowable Thickness After Refinish

24.89 mm

0.980 in

  • Rotor Thickness (new)

26.2 mm

1.03 in

  • Rotor Maximum Allowable Lateral Runout

0.051 mm

0.002 in

  • Rotor Maximum Allowable Scoring

1.5 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

JC1 (Front)

  • Rotor Discard Thickness *

27.5 mm

1.08 in

  • Rotor Minimum Allowable Thickness After Refinish

28.0 mm

1.10 in

  • Rotor Thickness (new)

29 mm

1.14 in

  • Rotor Maximum Allowable Lateral Runout

0.051 mm

0.002 in

  • Rotor Maximum Allowable Scoring

1.5 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

JC1 (Rear)

  • Rotor Discard Thickness *

18.50 mm

0.728 in

  • Rotor Minimum Allowable Thickness After Refinish

19.64 mm

0.735 in

  • Rotor Thickness (new)

20 mm

0.787 in

  • Rotor Maximum Allowable Lateral Runout

0.051 mm

0.002 in

  • Rotor Maximum Allowable Scoring

1.50 mm

0.059 in

  • Rotor Maximum Allowable Thickness Variation

0.025 mm

0.001 in

* All brake rotors have a discard dimension cast into them. Replace any rotor that does not meet this specification. After refinishing the rotor, replace any rotor that does not meet the minimum thickness specifications.