Front Suspension Inspection and Repair

Ride Height, Springs, and Chassis Geometry

Ride height can affect alignment angles, depending on suspension design; measure it under the manufacturer's specified conditions before making alignment adjustments. Before conducting an alignment, technicians must measure ride height on a flat, level surface. The vehicle's tires must be inflated to specification, and the fuel tank and cargo must be loaded according to the manufacturer service information. Because front ride height directly influences camber, caster, and toe depending on the suspension design, skipping this check can lead to incorrect alignment adjustments.

A sagged spring usually lowers curb height; a broken spring may lower it or cause noise or an uneven vehicle attitude, depending on where it broke. Conventional, non-load-assisting shock absorbers primarily damp suspension motion and do not provide the primary spring support or normally set curb ride height. Unequal side-to-side ride height can change camber or caster, depending on suspension design; measure ride height and alignment angles to identify the cause of a pull. As a general rule, a vehicle tends to pull toward the side with more positive camber or the side with less positive caster. If ride height is below specification, check loading, tires, spring seats, insulators, and other applicable causes; replace a spring when diagnosis confirms it is defective, following manufacturer service information on whether to replace the opposite spring as well. Spring insulators and silencers must be inspected and installed properly to prevent metal-to-metal contact, chassis squeaks, rattles, and abrasive perch wear.

Handling coil springs requires strict safety practices. Spring compressors store tremendous mechanical energy; technicians must ensure the tool is installed correctly with all safety locks fully engaged before compressing the spring. If the torsion-bar suspension has a ride-height adjustment, use the manufacturer's specified support, adjustment, settling, and measurement procedure; verify ride height before checking alignment. Some torsion bars are directional and marked specifically for left- or right-side installation; these must always be returned to their designated sides per manufacturer service information.

Suspension travel is physically limited by jounce and rebound bumpers. Jounce bumpers cushion the suspension near the end of compression travel and help prevent damaging contact between components; their location and the components they protect vary by suspension design. Rebound bumpers prevent metal-to-metal impact when the suspension reaches full extension or droop. Deteriorated, crushed, or missing bump stops cause harsh bottoming-out thumps and allow excessive travel that can damage shocks, struts, or other suspension components.