393.47E — Slack adjuster defective
FMCSA violation code under Vehicle Maintenance. 180,363 events recorded in roadside inspections. Severity weight: 7.
Violation Description
Automatic or manual slack adjuster on CMV is defective or out of adjustment.
About This Violation Code
Code 393.47E falls under the Vehicle Maintenance BASIC category in FMCSA's Safety Measurement System (SMS). It carries a severity weight of 7 (scale 1-10, higher = more severe).
When this violation is cited during a roadside inspection, it contributes to the carrier's Vehicle Maintenance BASIC score. Carriers with high BASIC percentiles may be prioritized for FMCSA interventions including warning letters, investigations, or compliance reviews.
Regulatory Reference
Federal Motor Carrier Safety Regulations
This violation references 49 CFR 393.47E in the Federal Motor Carrier Safety Regulations.
Top Enforcing States
Where 393.47E is most commonly cited (last 180 days)
Click a state to see roadside inspection activity, top stations, and carrier profiles in that jurisdiction.
Citation Trend (12 months)
Monthly count of 393.47E citations. Red bars mark months with OOS-triggering citations.
Most Active Stations
Inspection stations citing 393.47E most often (last 180 days)
Often Cited Together
Other violations commonly found on the same inspection (last 90 days)
Citation patterns suggest related root causes (e.g., HOS violations paired with logbook errors).
Top Carriers Cited
Ranked by frequency • 58,604 carriers total • Page 1 of 2345
Top Carriers with 393.47E Violations
Showing 25 of 58,604
Recent Inspections
Latest inspections where 393.47E was cited • 180,363 total events • Page 7215 of 7215