FMCSR 393.50(b) Steering Mechanism Defects — Driver Q&A

No, but it's rare when it does. Across our 13 million inspection records, 393.50(b) citations result in an out-of-service order only 3.3% of the time. That's 2 OOS instances out of 61 all-time citations in our database. The national average OOS rate across all FMCSR codes is 31.4%, so steering defects are pulled off the road far less often than most violations. You'll likely receive a citation to fix rather than an immediate shutdown, but don't delay repairs—a defective steering mechanism is a safety-critical issue.

This violation carries a CSA severity weight of 8 points. The exact number of points added to your CSA record depends on how FMCSA weights this within the Vehicle Maintenance BASIC category in the 30-day rolling period—each citation in that window accumulates, and the total impacts your score. One 393.50(b) citation alone won't tank your CSA, but combined with other maintenance violations, points add up quickly. Check your official FMCSA CSA profile at SaferTrucks.org to see your current score and violation history.

First, document the inspection report and citation number. Second, schedule an immediate inspection of your steering mechanism—have a qualified mechanic diagnose the exact defect (play in the steering wheel, worn tie rods, damaged pitman arm, etc.). Third, do not operate the vehicle unsafely; if steering is compromised, arrange for repair before your next run. Fourth, keep all repair receipts and documentation. Fifth, if you believe the citation was issued in error, you can submit a DataQs challenge through FMCSA's online portal, but you'll need clear evidence the steering was functional at the time of inspection. Don't ignore it—steering safety is non-negotiable.

It's less frequently cited than peer violations but handled differently. Our data shows 393.9(a) (inoperable lamps) has 660,737 citations with a 15.4% OOS rate, and 393.47E (slack adjuster defects) has 180,363 citations with 0% OOS rate. By contrast, 393.50(b) has only 61 citations with a 3.3% OOS rate. The low citation volume doesn't mean it's less serious—it suggests steering defects are caught and repaired quickly, or occur less frequently. What matters: steering is critical to vehicle control and safety. The low OOS rate reflects how rare it is for inspectors to find defects severe enough to ground a truck immediately.

Yes, you can challenge any roadside inspection finding through FMCSA's DataQs (Data Quality System) portal. For a steering defect citation, your challenge has the best chance of success if you can provide evidence—photos, mechanic reports, or inspection records—showing the steering mechanism was functional and properly maintained at the time of the roadside inspection. Document the exact condition the inspector cited (e.g., loose steering wheel, binding, visible damage) and gather proof it wasn't present. Submit your challenge within 90 days of the inspection. Vague or undocumented disputes are harder to win, so specificity and supporting evidence are key.

Across our 13 million inspection records, 393.50(b) is cited very infrequently—only 61 times all-time, ranking #1,569 out of 3,036 FMCSR codes by total citation volume. The low frequency means there is no clear geographic concentration in our dataset. The carriers cited include Texas Materials Group Inc, Great Dane LLC, Clark Freight Lines Inc, and others, each with only 1 citation. Without sufficient data to identify a top-3 state pattern, the takeaway is: steering defects are not a widespread compliance issue. This suggests most fleets are catching steering problems before roadside inspections, which is good fleet management.

Very urgent. Although our records show zero citations in the last 90 days and zero in the last 12 months, that absence doesn't mean the violation is obsolete—it reflects very tight steering inspection standards. A defective steering mechanism is a catastrophic safety risk: loss of steering control can cause rollover, jackknife, or collision. You should repair it before your next mile, not before your next inspection window. Do not gamble with steering safety. Inspectors treat steering defects seriously because drivers and the public depend on it. Fix it immediately, document the repair, and keep receipts as proof of compliance.

FMCSA violations are recorded at both the driver and carrier level under the CSA program. A 393.50(b) citation typically records the carrier's vehicle maintenance record (since it's a truck defect, not a driver action), but if you were operating the vehicle and failed to conduct or report a pre-trip inspection that would have caught the steering issue, driver accountability may apply. The violation impacts your carrier's Vehicle Maintenance BASIC score, which affects their safety rating and DOT audit risk. As a driver, it reflects on your training and awareness. Always perform thorough pre-trip inspections and report defects immediately—that's your first line of defense.