Wheel Alignment Diagnosis, Adjustment, and Repair
Angles that matter
Alignments revolve around caster, camber, toe, and thrust angle, with secondary angles (SAI/KPI, included angle, scrub radius, turning angle) used mainly for diagnosis. On a solid I-beam front axle camber is built in and not adjustable; toe is the routine adjustment, made at the tie rod or drag link. Caster may be adjustable only with shims on some axles, or only by cold-bending the axle per OEM procedure. Worn kingpins, bent spindles, and sagging springs make any reading meaningless, so inspect and set ride height first.
Sequence and traps
Caster and camber first, toe last, because toe changes with every other adjustment. Center the steering gear on its high point, then equalize both tie rod ends so the wheel is straight; do not simply move one sleeve. Thrust angle comes from the rear axle's position relative to the frame, not from the front end, so a truck that dog-tracks has a rear axle, suspension, or frame problem. Total toe is the sum of both wheels' toe; per-side readings are half of it.
Worked example
Convert toe from inches to degrees with: degrees ≈ inches ÷ tire diameter × 57.3. A 1/8 in (0.125 in) total toe on a 40 in tire gives 0.125 ÷ 40 × 57.3 ≈ 0.18° total, or about 0.09° per side. Compare that to the OEM spec before turning a sleeve.