Suspension bushings are the rubber and polyurethane isolators that keep your truck's control arms, leaf springs, and sway bars quiet and aligned. They wear slowly, which means a driver rarely notices the degradation until something else fails.
The first sign is usually a clunk over sharp bumps — a single, metallic knock from the front axle on potholes or expansion joints. That's a control arm bushing tearing. Left alone, it lets the arm shift under load and changes camber enough to cup the front tires.
The second sign is steering wheel vibration at a specific speed range, often between 55 and 65 mph. Worn bushings allow the front end to oscillate at its resonant frequency; the vibration disappears above and below that band.
Third is uneven tire wear on the inside or outside shoulder of the front tires. If your alignment shop keeps returning the same camber adjustment, the bushings are no longer holding the geometry between services.
Fourth is a pull or drift under braking. The front end shifts as weight transfers forward, and a worn bushing lets one side compress more than the other, pulling the truck toward the worn side.
Fifth is visible cracking or separation when you inspect the bushing with a light. Any rubber that's split through to the inner sleeve is past due for replacement — the bushing is no longer doing anything except locating the arm by metal-on-metal contact.