What 393.205(b) means in plain language
This regulation requires that the stud and bolt holes on your wheel rims remain in proper condition. Over time, repeated stress from driving, heavy loads, and vibration can cause these holes to stretch or become enlarged—a condition called elongation.
When holes elongate, the studs or bolts that hold your wheel in place no longer clamp down securely. This creates a serious safety risk: wheels can loosen, shift, or even separate from the axle during operation. A roadside inspector checking your vehicle will examine the rim holes closely to ensure they maintain their original size and shape.
This isn't about cosmetic wear. Elongated holes mean your wheels aren't being held with the force and consistency they need to be. A mechanic can identify this by looking at the rim directly or by noting excessive movement when attempting to tighten studs or bolts.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.205(b) citations are uncommon. Our data shows 205 all-time citations for elongated wheel stud and bolt holes, with zero citations in the last 12 months and zero in the last 90 days. This code ranks #1204 out of 3,036 FMCSR codes by citation volume.
However, when inspectors do cite this violation, they take it seriously. Our inspection records show a 74.1% out-of-service rate for this code. This is significantly higher than the all-FMCSR average OOS rate of 31.4%, meaning inspectors place nearly three-quarters of vehicles cited for elongated wheel holes out of service on the spot. Of the 205 all-time citations in our database, 152 resulted in immediate out-of-service orders, while 53 did not.
The rarity of citations combined with the high severity rate suggests that this violation may slip through informal inspections but triggers strict enforcement when detected during formal roadside checks.
Who gets cited most
Our inspection records do not include state-level or specific geographic breakdowns for this code. However, our data shows that elongated wheel stud and bolt holes violations have been distributed across multiple smaller carriers rather than concentrated in any single fleet. No single carrier appears more than twice in our all-time citation history for this code, indicating that the issue is sporadic rather than systemic to any particular operation.
The top vehicle makes cited for 393.205(b) include Freightliner (12 citations), Mack (11 citations), and Freightliner (abbreviated as FRHT, 10 citations). Kenworth and Volvo each appear in 8 citations. These data reflect the market share of Class 8 tractors on U.S. roads and do not indicate that any single manufacturer's wheels are inherently prone to elongation.
How severe is this compared to similar codes
Vehicle maintenance violations span a wide range of severity and citation frequency. Our inspection records show that 393.9(a) (inoperable required lamps) has been cited 660,737 times with a 15.4% OOS rate. By contrast, 396.3(a)(1) (general inspection, repair, and maintenance failures) shows 236,919 citations and a 45.3% OOS rate.
The 393.205(b) OOS rate of 74.1% places elongated wheel holes in the high-enforcement category. It is more severe than inoperable lamps (15.4% OOS) and structural defects like windshield condition (0.3% OOS), but comparable in severity to general maintenance failures. This reflects that wheel integrity is a direct load-bearing safety issue; inspectors view it as non-negotiable when detected.
How to avoid it
Perform regular wheel inspections before and after every shift. Check that all studs and bolts are tight and that the rim holes show no signs of visible enlargement or distortion. If a bolt feels loose or spins too freely, the holes may be beginning to elongate.
Re-torque wheel fasteners to manufacturer specification at regular intervals. Wheels loosen over time, especially on newer vehicles or after heavy braking or impact. Proper torque sequences prevent excess stress from concentrating on any single stud and hole.
Replace wheels showing signs of rim damage, corrosion, or previous loosening. If a wheel has already loosened once, the holes are likely compromised. Continuing to use it invites progressive damage and a citation.
Inspect Freightliner, Mack, and Volvo wheels with extra diligence during pre-trip checks. These makes appear most frequently in our data, suggesting they may have higher exposure to conditions that promote elongation.
Have a qualified mechanic inspect wheels if you notice uneven tire wear, vibration, or difficulty with lug nut adjustment. These are early signs that wheels are moving or that hole integrity is compromised.
Track wheel maintenance in your logbook or fleet app. Document when wheels are re-torqued and re-inspected. This creates accountability and helps catch problems before an inspector does.
The 74.1% out-of-service rate means that a citation for elongated wheel holes will likely ground your vehicle immediately. Prevention through regular, documented inspection is far simpler and cheaper than dealing with an out-of-service order on the road.