Wheels and Tires Diagnosis and Repair
Wheel systems
Know the two mounting systems cold. Hub-piloted wheels center on the hub bore and use flanged nuts with flat faces; stud-piloted wheels center on the studs and use ball-seat nuts. Mixing nuts, or using the wrong nut on the wrong wheel, damages the wheel and can lose the assembly. Torque in a star pattern to OEM spec, retorque per the OEM schedule, and inspect for elongated stud holes, cracks radiating from the holes, rust streaks (a crack indicator), and bent flanges. Demountable rims and multi-piece wheels must be deflated before any service; trapped air can kill.
Tires
Read the sidewall: size, load range, maximum inflation, and construction. Set pressure cold against the load/inflation table for the actual axle load, not the sidewall maximum. On duals, match tires by circumference (commonly within about 1/4 in) so the larger tire does not carry more load and overheat. Minimum tread depth is 4/32 in on steer tires and 2/32 in on all other positions. Wear patterns diagnose: center wear means overinflation, both shoulders underinflation, cupping points to damping or balance, and diagonal or feathered wear points to toe or misalignment.
Rule of thumb
When a tire complaint comes in, check inflation first, then runout and balance, then alignment. A tire that was run flat or badly underinflated stays suspect even if it looks fine; inspect the inner liner.