Centric 320.66050F Disc Brake Rotor - Rear

Centric GCX Rear Rotor for Heavy-Duty Trucks

The Centric GCX Elemental Protection Disc Brake Rotor, part number 320.66050F, is a rear vented rotor built for heavy-duty dual rear wheel applications. It is fully coated on non-mating surfaces to help resist rust and corrosion while maintaining OE-style braking performance.

Designed for Chevrolet Silverado 3500 HD, GMC Sierra 3500 HD, Chevrolet Express 3500, and related rear applications, this rotor uses Centric’s GCX coating strategy and application-specific metallurgy to match the brake pad friction profile and OEM material requirements.

Key Features

• Part number 320.66050F rear disc brake rotor
• Fully coated disc finish with coated hat for corrosion resistance
• Vented rotor design with smooth surface type
• Outside diameter: 325.000 mm (12.795 in)
• Nominal thickness: 30.000 mm (1.181 in)
• Discard thickness: 28.500 mm (1.122 in)
• 8-lug pattern with 165.100 mm (6.500 in) bolt circle
• Center hole diameter: 122.800 mm (4.835 in)
• Straight vane style and floating/DIH disc mounting

Product Details

Centric’s GCX Elemental Protection rotor line is engineered to deliver OE-level fit and braking behavior while adding protection on exposed surfaces. The RS200-style coating on non-mating areas helps reduce surface rust on the hat and outer surfaces, which is especially useful on work trucks and vans that see frequent exposure to moisture, road salt, and stop-and-go use. The metallurgy is matched to OEM-style carbon content for the application, helping maintain consistent rotor performance under load.

This rotor is a direct-fit rear option for 2001-2005 Chevrolet Silverado 3500, 2001-2005 GMC Sierra 3500, 2003-2008 Chevrolet Express 3500, 2003-2008 GMC Savana 3500, 2004-2007 Chevrolet Silverado 3500, 2004-2006 GMC Sierra 3500, 2007 Chevrolet Silverado 3500 Classic, 2007 GMC Sierra 3500 Classic, 2007-2008 Chevrolet Silverado 3500 HD, 2007-2008 GMC Sierra 3500 HD, and 2009-2010 Chevrolet Silverado 3500 HD / GMC Sierra 3500 HD rear dual rear wheel applications. This part cross-references Raybestos Brakes 56992FZN for the same application. Part number 320.66050F is also listed as a rear rotor for these heavy-duty platforms.

Common Problems This Rotor Can Address

• Rust buildup on exposed rotor surfaces
• Brake pulsation caused by worn or out-of-spec rear rotors
• Reduced braking consistency from heat-worn rotor surfaces
• Corrosion on trucks and vans used in harsh weather
• Fitment issues when replacing an OE-style rear vented rotor

Installation Notes and Tips

Verify rear axle configuration, wheel setup, and rotor dimensions before installation. Clean the hub mounting surface thoroughly to help prevent runout-related brake noise or pedal vibration. Inspect pads, calipers, and hardware condition during service, and confirm the rotor is installed on the rear position only for the listed applications.

Quality Assurance

Centric designs the GCX rotor line around OE performance targets and application-specific metallurgy, with coating coverage on non-mating surfaces for added corrosion protection. The brand states coverage for more than 98% of vehicles on the road across its expanding rotor catalog.