What 393.209D-STSCR means in plain language
This citation covers loose, missing, or defective wheel fasteners—the lug nuts and bolts that hold your wheels to the hub. When an inspector finds even one wheel with loose or missing fasteners, or fasteners that are damaged or don't meet specification, you receive this violation.
Wheel fasteners are critical to safe operation. A loose or missing lug nut can lead to wheel separation, a catastrophic failure at highway speed. The regulation requires that all fasteners be present, properly torqued, and in good working condition. This includes the fasteners themselves and their condition relative to the wheel and hub assembly.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.209D-STSCR is a relatively uncommon citation. We have documented 13 all-time citations for this code, with 9 in the last 12 months and 0 in the last 90 days. Despite the low citation volume, this code has a serious compliance track record: an 84.6% out-of-service rate.
To put that in context, the all-FMCSR average out-of-service rate sits at 31.4%, meaning this violation is nearly 2.7 times more likely to result in an immediate out-of-service order than the typical vehicle maintenance code. When an inspector finds loose or missing wheel fasteners, they do not hesitate to ground the vehicle until the defect is corrected. Of the 13 citations in our database, 11 resulted in out-of-service placement.
In the last 12 months, the citation volume has been steady but sparse: 1 citation in June 2025, 1 in July, 2 in August, 2 in September, 2 in October, and 1 in November 2025. The absence of citations in the last 90 days suggests either effective prevention across the fleet or lower inspection frequency targeting this specific defect.
Who gets cited most
Our data shows that Florida accounts for the highest citation count in the last 180 days, with 2 citations and a 100.0% out-of-service rate. This limited geographic data reflects the overall rarity of this violation, but Florida's perfect OOS conversion rate indicates inspectors in that state take wheel fastener defects very seriously.
No single carrier dominates the all-time citation list. Our records show fleets such as Butler Trucking LLC (USDOT 320270), Servicio de Transporte Internacional y Local SA de CV (USDOT 557341), Michaels Transportation Service Inc (USDOT 575313), and eight other carriers, each with 1 citation. This scatter across the carrier universe suggests the violation is not concentrated in any particular fleet profile or operation type.
How severe is this compared to similar codes
Wheel fastener defects sit in the Vehicle Maintenance category alongside other critical safety codes. By volume, they are far less common than related violations: inoperable required lamps (393.9(a)) have 660,737 citations with a 15.4% OOS rate, and inspection/repair/maintenance violations (396.3(a)(1)) have 236,919 citations with a 45.3% OOS rate. Lighting and general maintenance are inspected far more frequently.
However, when comparing severity—the likelihood of being pulled out of service—393.209D-STSCR's 84.6% OOS rate exceeds almost all peer codes. Slack adjuster defects (393.47E) have 180,363 citations but only a 0.0% OOS rate. Windshield condition violations (393.78) account for 157,894 citations with just a 0.3% OOS rate. The data is clear: inspectors treat loose or missing wheel fasteners as an immediate safety threat requiring removal from service, not a warning or repair notice.
How to avoid it
Prevent this citation with these driver-focused actions:
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Check all wheel fasteners during every pre-trip inspection. Walk around your entire truck. Look for missing lug nuts (you should see the same number on each wheel position). Look for fasteners that are visibly loose or corroded. Tap each one lightly with your hand to feel for movement. If you find any loose fasteners, do not operate the vehicle; notify your fleet immediately.
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Inspect after heavy braking or impact. Rough roads, hard braking, and accidents can loosen fasteners. If you hit a pothole, bounce hard, or experience any unusual vibration, stop safely and perform a wheel fastener check before continuing.
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Verify proper torque after wheel work. If your fleet recently changed tires, repaired a brake system, or performed suspension work, confirm that all fasteners were re-torqued to specification. Technicians should document this in the vehicle maintenance log.
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Monitor wheel condition continuously. Rust, corrosion, or deformation of the wheel rim or hub can create gaps that loosen fasteners over time. If you notice surface rust or pitting around the wheel, flag it for maintenance inspection.
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Report loose fasteners immediately. If you discover a loose or missing fastener during operation, pull over safely, turn on hazard lights, and contact your dispatcher or safety team. Do not continue driving; a single missing fastener is a safety event that requires repair before re-dispatch.
The 84.6% out-of-service rate for this code reflects the safety-critical nature of wheel fasteners. Inspectors will remove your truck from service rather than allow continued operation with defects. Regular, thorough pre-trip inspections and prompt reporting of any defects are your best defense.