Steering System Inspection
The steering system inspection covers all components from the steering wheel through the front wheels. Steering system failure is one of the most dangerous mechanical failures possible in a CMV because it eliminates the driver's ability to control direction entirely. Even partial steering system degradation — excessive play, worn linkage, low power steering fluid — creates a safety risk that worsens with vehicle speed and payload. The pre-trip steering inspection must be thorough and systematic.
Steering wheel play (free play) is the distance the steering wheel moves before the front wheels begin to respond. FMCSA out-of-service criteria allow a maximum of 2 inches of play for vehicles with manual steering and 4.5 inches for power-assisted steering. The driver checks this by holding the steering wheel lightly and moving it left and right to feel the 'dead zone' before the wheels respond. Excessive play indicates worn steering gear, worn tie rod ends, worn drag link, or worn kingpins. A vehicle with excessive steering play wanders and requires constant correction, exhausting the driver and creating a lane control hazard.
The drag link, tie rods, and steering gear box must be visually inspected for cracks, missing cotter pins or castle nuts, and visible wear at connection points. The tie rod ends — connecting the steering linkage to the front wheel steering arms — must be checked for looseness by pushing and pulling on each tie rod. A loose tie rod end that allows perceptible movement under hand pressure represents a condition where the front wheel can move independently of the steering input, potentially causing the wheel to turn sharply and unpredictably at speed.
Power steering hoses and connections were covered in the engine compartment inspection, but the driver should also check at the steering gear box for signs of fluid seepage where hoses connect to the box. The steering gear box itself — typically mounted to the frame rail — should be inspected for loose mounting bolts and any visible cracks. A loose steering gear box allows the entire steering system to flex when turning, creating play and reducing steering precision.