Steering Column and Linkage
What the candidate must know
Understand the column assembly: steering wheel, horn contacts, turn-signal/wiper switch, ignition lock, tilt/telescoping mechanism, upper and lower shaft, intermediate shaft with U-joints or a collapsible section, and the firewall boot. On a school bus, the column also carries the 4-way flasher and stop-arm controls on many chassis, so electrical and mechanical faults often overlap. Linkage knowledge includes tie rods, tie-rod ends, drag link, steering arm/knuckle arm, idler arm, pitman arm, and center link - know which joints are adjustable for toe and which are fixed.
Traps in questions
- Confusing tie-rod sleeve adjustment (toe) with drag-link adjustment (centers the steering wheel/gear).
- Forgetting that a collapsible column is a safety feature and must never be repaired by welding or straightening.
- Overlooking that a loose pitman arm nut or worn idler arm produces wander that looks like gear play.
- Missing that a binding tilt mechanism or column bearing can cause hard steering or a steering wheel that will not return.
Rule of thumb / worked example
When the steering wheel is off-center but the vehicle tracks straight, do not simply pull and re-index the wheel. First verify toe is correct, then adjust the drag link or tie-rod sleeves equally to center the wheel while keeping total toe within spec. Pulling the wheel only hides the real misalignment and can leave the turn-signal cancel cam and clock spring out of position.