What 393.71G-CDIMT means in plain language
A fifth wheel assembly is the coupling mechanism that connects a tractor to a semi-trailer. When an inspector cites you for 393.71G-CDIMT, they're saying the fifth wheel on your truck is defective, has excessive wear, or is not properly secured.
This covers a range of conditions: cracks or breaks in the casting, bent or worn components, loose bolts or fasteners, damaged locking jaws, worn kingpin pockets, or misalignment that prevents the trailer from coupling safely. The regulation requires that your fifth wheel remain structurally sound and securely fastened to the vehicle frame.
Why does this matter? A compromised fifth wheel can allow the trailer to shift, separate, or jackknife during braking or turns—creating an immediate risk to you, other motorists, and cargo.
What our enforcement data actually shows
Across our database of 13 million+ roadside inspections, we've recorded 42 all-time citations for 393.71G-CDIMT, with 32 citations in the last 12 months and 4 in the last 90 days. This ranks the code at #1680 of 3,036 FMCSR codes by citation volume—making it a relatively uncommon violation.
The out-of-service rate tells an important story. Of the 42 total citations, only 2 resulted in an out-of-service order, yielding a 4.8% OOS rate. This is substantially lower than the all-FMCSR average OOS rate of 31.4%, suggesting that when inspectors catch fifth wheel defects, they're often at a stage where repair is feasible and the vehicle can continue under guidance rather than being immediately prohibited from operation.
Looking at recent monthly data, citations have been scattered but steady: we saw 2 citations in April 2025, 3 in May and June, 4 in August and November, and a peak of 6 in December 2025. The 2 out-of-service placements both occurred in September 2025, indicating that seasonality or specific defect severity may influence enforcement outcomes.
Who gets cited most
Our inspection records show Pennsylvania leads with 5 citations over the last 180 days (0.0% OOS rate), followed by California with 3 citations (0.0% OOS rate) and Massachusetts, Wyoming, and Georgia each with 2 citations (all 0.0% OOS rates). Across these top states, not a single citation resulted in an out-of-service order, consistent with the national pattern for this code.
Regarding specific carriers, our data shows fleets such as Cole's Towing & Recovery Inc with 2 citations and multiple other carriers with single citations each. This distribution reflects the nature of the violation: fifth wheel defects are scattered across carrier types and geographies rather than concentrated in any particular fleet profile.
How severe is this compared to similar codes
To understand where 393.71G-CDIMT sits in the vehicle maintenance landscape, consider peer codes in the same category.
393.9(a) — Inoperable required lamps has generated 660,737 citations with a 15.4% OOS rate. While lamps are far more frequently cited, they carry a moderate enforcement consequence.
396.3(a)(1) — Inspection/repair/maintenance (general) accounts for 236,919 citations with a 45.3% OOS rate—nearly half of all citations result in out-of-service orders, making it significantly more severe in enforcement terms.
393.47E — Slack adjuster defective has 180,363 citations but a 0.0% OOS rate, similar to 393.71G-CDIMT's pattern. Both codes involve brake and coupling systems, yet inspectors appear to take a remediation-first approach rather than immediate prohibition.
The low OOS rate for 393.71G-CDIMT suggests inspectors have confidence that drivers can address the defect promptly—but don't take that lightly; the citation itself carries a CSA severity weight of 8, meaning it contributes to your safety profile and may trigger follow-up scrutiny.
How to avoid it
Prevention starts with systematic pre-trip inspection. Based on patterns in our enforcement data, here's what to focus on:
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Walk around and physically inspect the fifth wheel before departure. Look for visible cracks, bent metal, rust perforation, or separation from the frame. Rock the trailer side-to-side by hand (if safely parked) to feel for play or movement.
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Check all visible bolts and fasteners connecting the fifth wheel to the frame. Loose fasteners are a common find; use a wrench to verify they're tight. Don't rely on a visual once-over.
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Examine the kingpin pocket for wear or damage. If the trailer's kingpin sits loosely or wobbles when you move the coupling assembly, the fifth wheel needs service.
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Verify the locking jaws close and hold securely. Manually push the trailer coupling toward the kingpin and ensure the jaws clamp down smoothly. A sluggish or incomplete lock is a red flag.
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Document your inspection. Our data shows that co-occurring citations often include defects related to periodic inspection records (396.17C-PI has appeared 2 times alongside 393.71G-CDIMT in the same inspection). Keep dated notes or photos of your fifth wheel condition; if you're cited, evidence of regular, documented maintenance strengthens your defense.
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Schedule professional inspection annually or after high-mileage cycles. If you're operating a Ford, Freightliner, or Kenworth (the top three vehicle makes cited for this code), don't assume the fifth wheel assembly is immune to wear. Towing and recovery operations (our data shows Cole's Towing & Recovery Inc cited multiple times) should consider more frequent checks because their work often involves stress-loading the coupling.
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Address defects immediately. Don't defer a repair just because the violation isn't automatically out-of-service. A citation on your record counts toward your CSA safety score, and a follow-up inspection may be more aggressive. Fix it before the next roadside stop.