What 393.50(c) means in plain language
When an inspector cites you for 393.50(c), they've found that your steering mechanism is defective, broken, or not functioning properly. This isn't about worn tire tread or a missing light—it's about the core system that lets you control direction. That includes the steering column, linkages, pitman arm, tie rods, wheel bearings, or any other component that translates your hand movements at the wheel into actual directional control of the vehicle.
The regulation requires your steering system to be in working condition and safe to operate. If an inspector observes play in the steering wheel, loose connections, damage to steering components, or any sign that steering effort is abnormal or the system is compromised, they can issue this citation. The key point: the system must function properly. If it doesn't, your truck should not be on the road.
What our enforcement data actually shows
Across our 13 million inspection records, 393.50(c) citations are uncommon. We've recorded only 1,042 all-time citations for this violation, and notably, there have been zero citations in both the last 12 months and the last 90 days in our database. This suggests that either steering defects are being caught and corrected upstream, or inspectors are rarely encountering them at roadside.
When 393.50(c) citations are issued, they very seldom result in an out-of-service order. Our data shows a 1.0% OOS rate for this code—meaning 10 vehicles out of 1,032 cited were actually removed from service. This is dramatically lower than the all-FMCSR average OOS rate of 31.4%. That gap indicates inspectors typically view steering defects as correctable on the spot or through scheduled maintenance, not as immediate safety hazards requiring roadside removal. However, the rarity of citations also suggests that when steering problems do appear, they're serious enough to warrant attention.
Who gets cited most
Our inspection records show that steering defect citations cluster among specific carrier types. AUTOTRANSPORTES VARELA DAVILA SA DE CV (USDOT 1716824) leads with 16 all-time citations, followed by QUALITY TANK SA DE CV (USDOT 2864600) with 12 citations, and LOS ANGELES UNIFIED SCHOOL DISTRICT (USDOT 2807610) with 10 citations. These data points reflect the operations profiles of these carriers—tank haulers and large-fleet school districts operate high-mileage vehicles that see intensive wear cycles, which can accelerate component degradation.
At the equipment level, our data shows Freightliners (FRHT) account for 181 of all citations under this code, followed by Kenworths (KW) with 65 citations. This distribution likely reflects market prevalence—Freightliners are the most common long-haul tractor in North America—but it also underscores that no make is immune to steering wear if maintenance schedules slip.
How severe is this compared to similar codes
Steering defects are far less commonly cited than other vehicle maintenance violations in the same regulatory category. For context, inoperable lamps (393.9(a)) generated 660,737 citations with a 15.4% OOS rate—over 630 times more frequent than steering issues. Slack adjuster defects (393.47E) produced 180,363 citations but carried a 0.0% OOS rate, suggesting inspectors treat brake component wear as a correctable item. Windshield defects (393.78) generated 157,894 citations with only a 0.3% OOS rate.
The rarity of 393.50(c) citations, paired with the low OOS rate, suggests that steering systems are generally maintained well across the industry, or that defects are subtle enough that they escape roadside inspection. When they do surface, they're handled as maintainable items rather than immediate failures.
How to avoid it
Steering defects are preventable through disciplined pre-trip inspection and maintenance:
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Check steering wheel play before every start. Grasp the wheel at 3 and 9 o'clock and apply gentle side-to-side pressure with the engine off. Excessive movement—more than 2 inches of wheel rotation before the wheels begin to move—signals worn linkage or bearings. If you feel it, report it to maintenance and do not operate the vehicle.
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Feel for resistance and binding during slow-speed maneuvers. During your pre-trip, slowly turn the wheel full lock left and right in a parking lot at idle. The steering should be smooth and progressive. Any grinding, clunking, or sudden resistance indicates component wear or damage that needs immediate inspection.
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Listen for clunks and creaks during turns. Worn tie rods, pitman arms, and idler arms produce audible noise when they fail. If you hear new sounds during steering input, especially at higher speeds, have the system inspected before the next run.
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Monitor steering effort. If the truck suddenly feels harder to steer, or if steering becomes intermittently stiff, the power steering system or hydraulic lines may be compromised. Don't ignore a change—it's often an early warning sign.
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Include the steering linkage in your monthly lubrication schedule. Grease fittings on tie rods, pitman arms, and idler arms reduce wear. Dry, neglected components fail faster. If your fleet operates older Freightliners or Kenworths, which make up the bulk of citations, establish a more frequent inspection interval for steering geometry.
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Have the steering column inspected if there's been any front-end impact. Even minor accidents can misalign or crack steering components invisibly. A pre-trip alone may not catch hidden damage—a shop inspection after any collision is prudent.