Steering Arm Capscrew Failures

What NHTSA is examining

The Office of Defects Investigation (ODI) opened this investigation based on one (1) Vehicle Owner Questionnaire (VOQ) and associated Police Accident Report (PAR) that described a crash where the vehicle had a separated steering linkage at one wheel-end as the result of lower steering arm capscrew failures.It was unknown at the time whether the separation caused the crash or was the result of the crash.Recall 15V-613 corrected an under-torque issue in upper steering arm capscrews on these vehicles.ODI opened this Recall Query to assess the scope and remedy of the 15V-613 recall.ODI collected the front axle from the crash vehicle for inspection and sent an Information Request Letter (IR) to Daimler Trucks North America (DTNA).The Vehicle Research and Test Center (VRTC) analyzed the crash truck's front axle.Based on the fracture surfaces of the capscrews and numerous witness marks on the tires, wheels, and vehicle, VRTC determined that the steering linkage separated due to the crash and was not the cause of the crash.However, VRTC noted that the capscrews on the opposite wheel end were at a much lower torque value than specified by the manufacturer.In DTNA's IR response, they reported one additional crash where a separated steering linkage was observed.DTNA determined the separation was the result of the crash and not the cause of the crash.DTNA had no complaints and all warranty reports were related to the upper steering knuckles and recall 15V-613.During the investigation…

Vehicles under investigation