During a comprehensive pre-trip inspection, a commercial driver observes several specific conditions on a combination vehicle's wheels and tires. Match each observed diagnostic finding to its correct regulatory mandate or specific safety hazard.
- Steer axle tire measuring 5/32-inch tread depth in the center grooves, but 3/32-inch in an outer major groove.Violates FMCSA minimums; steer tires must maintain at least 4/32-inch depth in every major groove, not as an average.
- Dual tire assembly containing one radial-ply tire and one bias-ply tire mounted together on the same wheel end.Prohibited configuration; differing carcass constructions cause uneven load distribution and rapid overheating.
- Aluminum wheel rim displaying a hairline, shiny fracture extending outward from a stud hole.Critical structural failure indicator of loose hardware; risks a catastrophic wheel separation event and requires immediate replacement.
- Steel wheel rim exhibiting a small, smoothly ground bead weld repair near the outer flange.Categorical Out-of-Service condition; applying heat to repair any wheel component is strictly forbidden by regulations.
Answer
The steer tire with 3/32-inch outer tread violates the 4/32-inch every-groove mandate. The mixed radial/bias-ply duals are a prohibited configuration due to uneven load distribution. The shiny fracture from a stud hole is a critical structural failure indicator risking wheel separation. The welded steel rim is a categorical Out-of-Service condition as heat repairs are strictly forbidden.
Each specific physical observation directly corresponds to a specific regulatory standard: the 4/32-inch minimum applies per groove, radial/bias mixing is forbidden due to unequal physics, shiny cracks around studs indicate loose mounting hardware, and rim welding is an absolute prohibition.
Step-by-Step Solution
Key Concept
Advanced wheel and tire defect diagnosis and regulatory compliance criteria.
Estimated Time:1m 30s