Wilwood Rear GT-Slotted Brake & Internal Parking Kit — Ford Mustang (2005–2014), Red Superlite 4R, 12.88-Inch Rotors

GT-slotted rotors and red Superlite calipers define this S197 Mustang rear package. It includes internal parking-brake hardware for the specified axle flange, with a possible sensor-clearance relief and separate cable kits addressed in DS531. Bill Wood founded Wilwood Engineering in 1977; the company is based in Camarillo, California. Wilwood designs and manufactures calipers, brake rotors, master cylinders, valves, fittings and brake lines as part of its disc brake systems and component range for motorsport, street-performance and specialized applications. Each component must suit the requirements of the complete brake installation.

Technical Details

• Manufacturer part number: 140-9221-R
• Caliper body: Forged aluminum; hydraulic inlet: 1/8-27 NPT
• Rotor surface finish: Black Electro Coat; rotors are not supplied burnished
• Rotor/hat wheel-stud clearance pattern(s): 5 x 4.5 in; 5 x 114.3 mm; 5 x 4.75 in; 5 x 120.65 mm; 5 x 5 in; 5 x 127 mm; the existing hub/axle pattern is retained
• Hat/rotor stud-hole clearance: 0.520 in; 13.21 mm; this is not a wheel-stud thread designation
• Required axle offset: 2.66 inches; measure from the axle flange to the housing flange as shown in the instructions
• Parking brake: internal drum/shoe assemblies included; cable, clevis and control hardware are separate
• Hydraulic hoses: not included; match the separate lines and fittings to the application
• Kit includes calipers, rotors and mounting hardware; replacement hubs and spindles are not included
• Not included: master cylinder and brake booster
• Wheel clearance: 17-inch wheels may fit; check the complete manufacturer caliper/rotor template
• Quantity: sold as one axle kit
• Service calipers: 4-piston Forged Narrow Superlite 4R; Red Powder Coat; radial mounting
• Brake rotors: 12.88 x 1.10 inches; Spec-37 Iron; GT Slotted; vented
• Included pad compound: BP-10; pistons: stainless steel

Fitment & Compatibility

For the listed 2005–2014 Ford Mustang rear applications, using the specified axle flange and 2.66-inch offset. The kit supplies an internal drum parking-brake assembly and retains the original wheel-speed sensor. Confirm the exact base, GT, Boss 302 or Shelby application and the actual axle before ordering.

DS531 may require a relief in the housing flange to reinstall the OE wheel-speed sensor. Rear flexlines 220-9248 are separate. Parking-cable kits are also separate: 330-11221 is specified for 2005–2010 and 330-12335 for 2011–2014. Check the 6.61-inch axle-flange limit and the required chamfer.

Review the complete fitment table below before purchase, retaining the restrictions attached to the chosen vehicle.

Adjust and test the mechanical parking brake as directed. Cable routing, tension and shoe adjustment affect its holding ability; do not rely on an untested parking brake alone to secure the vehicle on a slope.

Manufacturer Resources

• Wilwood kit specifications and wheel-clearance information
• Installation instructions and component list
• Axle-offset measurement worksheet

WARNING: This product can expose you to chemicals including Arsenic, Cadmium, Chromium (Hexavalent compounds), Lead, Nickel, Cobalt and Antimony Trioxide which are known to the State of California to cause cancer or other reproductive harm. For more information go to www.p65warnings.ca.gov.

For fitment help, contact PMB Performance with your VIN and details of any axle, spindle or brake changes. Our team has over 20 years of experience checking parts and fitment, including the dimensions that a model-year search cannot establish.

Vehicle Applications

Application Notes

1. Flexline kit 220-9248 used with Internal Drum P-brake Kit, Flexline kit 220-10417 used with CPB Kit.
2. Line kit included (manufacturer): None
3. Rear line-kit reference: 220-9248