What 393.70A means in plain language
When you receive a 393.70A citation, an inspector found that your fifth wheel, kingpin, pintle hook, drawbar, or other coupling device connecting your tractor to your trailer is defective. These components are safety-critical: they bear the full load of your trailer and must be mechanically sound to prevent separation during transport.
Defective in this context means the coupling shows visible wear, cracks, corrosion, loose bolts, improper alignment, or damage that compromises its structural integrity. The inspector doesn't need to see a catastrophic failure—evidence that the coupling cannot safely transmit braking or turning forces is enough for a citation.
Unlike some violations, 393.70A is not eligible for out-of-service placement, meaning the inspector will not order you off the road solely for this violation. However, if your coupling defect is severe enough that it creates imminent danger, an inspector might cite you under a different authority or require repair before you proceed.
What our enforcement data actually shows
Across our 13 million+ inspection records, 393.70A ranks #1538 out of 3,036 FMCSR codes by citation volume. We see 67 all-time citations for this violation, with 46 citations in the last 12 months and 10 in the last 90 days.
The out-of-service rate for 393.70A is 7.5%—meaning 5 vehicles were placed out of service out of 67 total citations. This is substantially lower than the all-FMCSR average of 31.4%, indicating that when inspectors cite coupling defects, they rarely deem the defect severe enough to immediately remove the vehicle from service. Most carriers cited for this violation are allowed to continue to a repair facility.
The monthly trend in our data shows 393.70A citations are relatively stable, ranging from 1 to 8 citations per month over the past year. May 2025 was the highest-volume month with 8 citations; February 2026 saw the highest out-of-service activity with 2 out of 4 citations resulting in OOS placement.
Who gets cited most
Our inspection records show the top three states for 393.70A citations in the last 180 days are:
- Texas: 20 citations, 1 out of service (5.0% OOS rate)
- Illinois: 1 citation, placed out of service (100.0% OOS rate)
Texas dominates the citation volume, accounting for the vast majority of 393.70A enforcement activity in our database. The OOS rate in Texas (5.0%) is lower than the national rate for this code (7.5%), suggesting Texas inspectors more often allow drivers to proceed to repairs. Illinois's single citation resulted in an out-of-service placement, but this represents a sample size of one and should not be over-interpreted.
Among carriers in our all-time database, our data shows fleets such as Antonio Gomez (USDOT 2505594) with 2 citations. The remaining cited carriers each have 1 citation in our records.
How severe is this compared to similar codes
393.70A exists in a category of vehicle maintenance violations. Here's how it compares to related coupling and suspension defects:
- 393.9 (Inoperable Required Lamp): 180,097 citations all-time, 6.9% OOS rate. Lighting violations are far more commonly cited (2,688× more frequently than 393.70A), though the OOS rates are similar.
- 393.47E (Slack Adjuster Defective): 180,363 citations all-time, 0.0% OOS rate. Brake system defects are cited at roughly 2,690× the frequency of coupling defects and are never placed out of service in our records, suggesting brake adjusters are cited primarily for documentation or minor wear issues.
- 396.3(a)(1) (Inspection/Repair/Maintenance — General): 236,919 citations all-time, 45.3% OOS rate. This broader maintenance violation is cited far more often (3,536× more frequently) and results in out-of-service placement in 45.3% of cases—nearly six times higher than 393.70A.
The rarity of 393.70A citations and the low OOS rate suggest that serious coupling defects are uncommon in the inspected population, or that coupling issues are cited under broader maintenance codes rather than this specific violation.
How to avoid it
Coupling device defects don't appear in isolation. Our inspection data shows that when 393.70A is cited, it frequently co-occurs with other violations:
- 393.9 (Inoperable Required Lamp) appears in 4 shared inspections in the last 90 days
- 393.207A (Suspension Defective) in 3 shared inspections
- 393.47E (Slack Adjuster Defective) in 2 shared inspections
This pattern suggests that vehicles with coupling defects often have broader mechanical issues. To avoid 393.70A:
- Inspect the fifth wheel during your pre-trip walk-around: Check for visible cracks, corrosion, or loose mounting bolts on the casting. Ensure the locking mechanism engages fully when the trailer kingpin is seated.
- Check kingpin and drawbar alignment: The kingpin should rest squarely in the fifth wheel jaw with no play side-to-side. If you can move the kingpin by hand, the fifth wheel is worn and must be replaced or repaired.
- Look for rust and scaling: Surface rust is normal, but deep pitting or flaking that creates sharp edges or thins the metal is a defect waiting to be cited.
- Verify all fasteners are tight: Walk around the fifth wheel with a wrench and confirm all bolts connecting it to the frame are snug. A single loose bolt can trigger a citation.
- Test pintle hooks and drawbars if applicable: If you pull lowboys or flatbeds with pintle attachments, ensure the hook eye is not cracked, the latch mechanism works smoothly, and the drawbar is straight with no visible bending.
- Schedule coupling inspection alongside brake and suspension work: Since 393.207A (suspension) and 393.47E (brake adjusters) commonly co-occur with coupling defects, have your shop inspect all three systems together during routine maintenance.
The good news: our records show that 393.70A enforcement is infrequent and out-of-service placement is rare. A 15-minute coupling inspection at the start of each shift is your best defense.