Vehicle report
Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
511388
The flanged wheel lug nuts on your vehicle may have been over-torqued during service to an incorrect torque specification in the Service & Owner's manuals. A yielded wheel stud may eventually break, which could lead to a wheel separating from the vehicle during operation. A wheel separating from the vehicle could cause a vehicle crash without prior warning and/or the wheel/tire could pose a risk to other vehicles or pedestrians.
551332
The add on component separates the tail light signal from an actual brake signal so the customers no longer need to mess with their brake controller when towing as the Freightliner M2 Chassis applies brake signal to the four-way flashers, which in turn will activate the brakes of a towed item, such as a trailer. In some states, it is required to activate the vehicle four-way flashers on certain Grades.
511078
Per notice from Cummins, the engine may be releasing air pollutants, which exceed California and Federal Standards.
Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.