Front Suspension Components

Radius arms are the longitudinal control arms that locate the front axle fore-and-aft on the early Ford Bronco's solid front axle suspension. They prevent the axle from moving forward or rearward under braking and acceleration while allowing up-and-down suspension travel. The factory radius arms are adequate for stock use, but upgraded heavy-duty or extended arms are popular for lifted and off-road builds due to the increased wheel travel, better ride and increased caster which improves drivablity.

Worn radius arm bushings on an early Bronco cause clunking over bumps, vague steering, and wandering at highway speeds. To check, jack up the front of the truck, grab the radius arm near the frame bushing, and try to move it fore-and-aft by hand. Any perceptible movement indicates the bushings are worn. Look for any visable cracks in the existing bushings, if cracked it's best to replace them. Replacement polyurethane bushings from Tom's Offroad restore precise axle location.

Radius arm drop brackets relocate the frame-side radius arm mount lower on the chassis, correcting the axle caster angle that changes when the Bronco is lifted. Without caster correction, a lifted early Bronco will exhibit wandering and twitchy steering. Drop brackets are an important component in any lift kit over 2 inches and are an option in most quality early Bronco suspension lift kits.

Heavy-duty aftermarket radius arms are a worthwhile upgrade for early Broncos used on rocky terrain or running larger tires. Factory radius arms can bend under severe impacts, which compromises alignment and handling. Aftermarket arms made from heavier-wall tubing or plate steel to resist bending and often provide better geometry for lifted applications. Tom's Offroad carries heavy-duty radius arm options engineered for the early Bronco's chassis.

Replacing early Bronco radius arms requires supporting the frame and axle separately, removing the coil springs and shocks, unbolting the arm at both the axle bracket and the frame mount, and installing the new arm in reverse. Always replace the bushings whenever replacing the arms. After installation, have the front-end alignment checked and adjusted, radius arm replacement changes the caster and toe settings that must be corrected by alignment.