Rear Left Trailing Arm - 1987 Mustang

The rear left trailing arm (lower control arm) on the 1987 Ford Mustang Fox platform is a stamped steel link connecting the 8.8-inch rear axle housing to the chassis frame rail. Identified by Ford part number E7ZZ-5A649-A, this component is mechanically identical across all 1979-1993 Mustang models, interchangeably using the earlier E5ZZ-5A649-A casting. Compatible donors include 1979-1986 Mercury Capri and 1978-1983 Ford Fairmont/Mercury Zephyr utilizing the same Fox platform architecture. When inspecting junkyard candidates, examine the large front eccentric bushing for dry rot and the rear axle bracket for cracked welds or distortion—common failures following hard launches or bottoming out. These arms are strictly side-specific due to asymmetrical bends providing exhaust clearance. Installation requires supporting the axle housing before removal and torquing the through-bolts to 73 lb-ft with the suspension loaded at ride height to prevent bushing bind. Consider upgrading to polyurethane bushings during replacement, as factory rubber deteriorates rapidly under performance driving conditions.