Wilwood Rear Superlite 4R Parking Brake Kit, Black, 12.88-Inch GT Rotors for Bronco Small Ford Axles

This rear package combines black radial-mount Superlite 4R calipers with slotted 12.88-inch Spec-37 rotors. iron hats work with the enclosed parking brake and the measured Small Ford Bronco axle-end arrangement. Bill Wood founded Wilwood Engineering in 1977, and the manufacturer is based in Camarillo, California. Wilwood designs and manufactures disc brake systems alongside calipers, master cylinders, rotors, fittings, brake lines and valves. The motorsport, street-performance and specialized ranges depend on components selected to work within a complete braking system.

Technical Details

• Manufacturer part number: 140-13321
• Application and package: Rear Brake Kits - Street Performance; Rear Kits; Disc; Parking; Sold as a kit.
• Hydraulic inlet: 1/8-27 NPT
• Wheel bolt pattern(s): 5 x 5.5 in; 5 x 139.7 mm
• Stud-hole / clearance provision: 0.640 in; 16.26 mm; diameter provision, not a thread designation
• Wheel diameter starting requirement: 17 in; 431.8 mm; verify the individual wheel against the installation drawing
• Rear axle-end interface: Small Ford Bronco; axle/flange offset 2.36 in; 59.94 mm
• Included mechanical components: Mounting hardware: Yes; hub(s): No; spindle(s): No
• Hydraulic components supplied: Master cylinder: No; brake booster: No; brake lines: No
• Specified pad compound: BP-10
• Separate rotor-hat specification: Iron; Black E-Coat; offset 1.540 inch; part 170-13326
• Rotor dimensions: 12.88 in; 327.15 mm outside diameter; 1.10 in; 27.94 mm thickness
• Rotor construction: Spec-37 Iron; Vented; GT Slotted
• Caliper assembly: Forged Narrow Superlite 4R; 4 pistons per caliper; Forged Aluminium body; Radial mount
• Piston and finish specification: Stainless pistons; Black calipers; Black Powder Coat

Fitment & Compatibility

Confirm the 2.36-inch offset, Small Ford flange and 5 x 5.50-inch pattern against DS1016. The nominal 17-inch wheel requirement does not replace a spoke-profile check, and cable adaptation remains separate.

The installation drawing specifies a 2.88-inch axle register and the corresponding centering-adapter arrangement. Check the housing pattern and axle offset, then confirm the flange fits within the 6.61-inch diameter limit with its 0.050-inch x 45-degree chamfer.

The installation reference identifies Small Ford Bronco rear applications with 2700-lb axle/10-inch drums for 1966–1973 and 2900-lb axle/10-inch drums for 1974–1975. The measured2.36-inch offset and actual housing flange still govern selection.

Hydraulic hoses/fittings and parking-brake cables, adapters and cable hardware are not included. Choose a compatible cable arrangement for the internal parking brake; universal cable systems may require vehicle or cable modifications.

Manufacturer References

• Wilwood exact kit specifications
• Wilwood installation instructions DS1016
• Axle measurement worksheet

Ask PMB Performance for help comparing the installation requirements. We have more than 20 years of experience working with brake parts and fitment.