Suspension

11 Lessons

Learn struts, control arms, ball joints, and how to diagnose ride and handling complaints.

Overview

The suspension system keeps the tires on the road and the passengers comfortable. This module covers MacPherson struts, double wishbone, multi-link, control arms, ball joints, bushings, sway bars, and the alignment angles that determine how the vehicle drives straight and handles corners.

Key Components

  • Struts and shock absorbers
  • Control arms and ball joints
  • Sway bar and end links
  • Springs (coil, leaf, air)
  • Wheel bearings and hubs

How It Works

The suspension connects the vehicle body to the wheels through a series of links, arms, and springs. Springs support the vehicle weight and absorb bumps. Shock absorbers (dampers) control spring oscillation. Ball joints and bushings allow controlled movement while maintaining alignment geometry.

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Common Problems

  • Worn struts causing bouncing and poor handling
  • Ball joint wear causing clunking and alignment issues
  • Sway bar end link rattle over bumps
  • Wheel bearing noise increasing with speed
  • Control arm bushing deterioration

Diagnostic Tips

  • Bounce test: push corner down, should return to rest in one bounce
  • Pry bar test for ball joint and bushing play
  • Road test at speed — wheel bearing noise changes with turning
  • Check ride height before doing alignment — springs sag

Related Systems

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