Hardware, Fasteners and Fittings

Suspension hardware, fasteners, and fittings are the connectors and adjusters that hold your suspension geometry in place and keep alignment settings where they belong. This category covers alignment cam bolts and shims, control arm bolts and washers, coil spring shims and spacers, toe adjusters, leaf spring hardware, and small but critical components like ball joint boots, strut mount nuts, and air suspension fittings. These parts fail through corrosion, stretch, and mechanical wear - corroded cam bolts seize and make alignment adjustments impossible, while worn shims or spacers allow camber and toe to drift outside spec, causing uneven tire wear. When buying, confirm torque specs and thread pitch match your application; many cam bolt kits are year- and model-specific due to eccentric slot sizing. OEM hardware is often worth the premium on alignment-critical fasteners. For shims, verify thickness increments match your alignment target and that the material grade suits your climate.

Signs you need replacement

• Uneven or rapid tire wear - Feathering on the inner or outer tread edge, or cupping across one axle, often points to camber or toe that has shifted due to worn shims, a loose cam bolt, or a missing spacer allowing the control arm to move under load.
• Vehicle pulls to one side on a straight, level road - If the pull persists after a fresh alignment, suspect a seized cam bolt that couldn't be fully adjusted, or a shim that has slipped or corroded flat, preventing accurate toe or caster correction.
• Clunking or knocking from the suspension over bumps - A loose or stripped control arm bolt, a worn strut mount nut, or a cracked ball joint boot allowing grease loss can all produce metallic clunking that worsens on rough pavement or during parking maneuvers.
• Alignment specs won't hold after adjustment - If your shop reports the vehicle is back out of spec within a few thousand miles, a cam bolt that is rounding in its slot or a shim that is shifting indicates the hardware itself needs replacement, not just another alignment.
• Visible corrosion, cracking, or torn boots on suspension fasteners - Split ball joint or control arm boots expose the joint to contamination and accelerate wear; corroded leaf spring bolts or beam axle mounts may crack under load rather than giving obvious warning before failure.

Frequently asked questions

• How often do alignment cam bolts and shims need to be replaced? There's no fixed mileage interval - these parts are typically replaced when alignment adjustability is lost, usually due to corrosion seizing the cam bolt in its slot. In salt-belt climates, proactive replacement every 80,000–100,000 miles or at each major suspension rebuild is reasonable. Always replace cam bolts if they show visible rust pitting or the eccentric slot is worn oval.
• Are aftermarket alignment shims and cam bolt kits as good as OEM? For cam bolt kits, quality aftermarket brands like Moog and Specialty Products Company meet OEM specs and include multiple adjustment positions. The key is matching thread diameter, pitch, and slot width exactly - cheap no-name hardware often has inconsistent cam profiles that prevent accurate alignment. For shims, OEM thickness tolerances are tighter, which matters most on vehicles with narrow alignment windows like performance cars or trucks with lifted suspensions.
• What else should I replace when installing new control arm bolts or cam bolts? Replace control arm bushings if they show cracking or deflection - new bolts through collapsed bushings won't hold alignment. Torque-to-yield control arm bolts must always be replaced, never reused. Budget $15–$60 for a cam bolt kit, $5–$25 per alignment shim set, and $10–$40 for a control arm bolt kit. Most DIYers with a torque wrench and alignment gauge can complete this work in 1–2 hours per corner.