Rear Left Brake Backing Plate/Dust Shield - 2018 Mustang

The Ford rear brake backing plate (dust shield) for the S550 Mustang prevents debris intrusion while shielding brake components from road moisture. For the 2018 GT and compatible models, primary Ford service number FR3Z-2C029-A covers the left/driver side, though later service replacements may carry JR3Z-2C029-A packaging. These plates interchange across 2015-2023 standard brake Mustangs regardless of engine variant—EcoBoost and base GT models share the same sheetmetal stamping provided they lack the Performance Pack option. When sourcing from junkyards, inspect the lower mounting ear for corrosion-induced cracking, a common failure point where road salt collects, and verify parking brake cable guides remain undamaged. Installation typically requires removing the rear axle shaft or caliper bracket; ensure the plate sits flush against the axle flange to prevent rotor contact noises. Never interchange with Performance Pack variants, as their larger rotors require distinct clearances that standard plates cannot accommodate without modification.