NHTSA Investigation RQ06008

FAILED TAG AXLE SWING ARMS

MCI ORIGINALLY FILED A DEFECT NOTIFICATION ON OCTOBER 20, 2003, (03V-411) TO ADDRESSCRACKS LOCATED ON THE TAG AXLE SWING ARM AT THE CONNECTION TO THE PIVOT SPINDLE TUBE.FOUR HUNDRED AND NINETY-THREE (493) MCI G4500 2000-2003 MOTOR COACHES WERE INVOLVED.MCI?S ENGINEERING ANALYSIS DETERMINED THAT INSUFFICIENT WELD METAL AND /OR WELD PENETRATION ON THE FAILED COMPONENTS COULD RESULT IN EARLY STRESS AND FATIGUE CRACKS AT A WELD JOINING THE TAG AXLE TO THE PIVOT TUBE ASSEMBLY.MCI'S FIELD REPAIR CONSISTED OF INSPECTING AND RE-WELDING THE TAG AXLE SWING ARM.A SMALL PERCENTAGE WERE NOT REPAIRABLE AND REQUIRED A FULL REPLACEMENT OF THE SWING ARM. ON JULY 18, 2006, ODI WAS CONTACTED BY A FLEETALLEGING THAT THEY HAD THREE TAG AXLE ARMS CRACK AND SUBSEQUENTLY BREAK IN THE SAME AREA REPAIRED BY MCI DURING THE SAFETY RECALL.AS A RESULT, ODI OPENED THIS RQ.MCI CONDUCTED FURTHER ANALYSIS AND DETERMINED THAT SOME OF THE PREVIOUSLY REPAIRED SWING ARMS, REPAIRED DURING RECALL 03V-411 MAY HAVE BEEN REPAIRED WITH EXISTING UNIDENTIFIED MICRO-FRACTURES AND/OR WELDS WITH INSUFFICIENT PENETRATION.THIS COULD LEAD TO FURTHER CRACKING AND RESULT IN A PARTIAL OR TOTAL SEPARATION OR THE TAG ARM. AS A RESULT OF THIS INVESTIGATION, MCI HAS ANNOUNCED A NEW SAFETY RECALL IN WHICH THEY WILL REPLACE ALL THE TAG ARMS WITH A NEWLY DESIGNED TAG AXLE SWING ARM.MCI'S NEW RECALL ACTIONRESOLVES THIS INVESTIGATION.THEREFORE, THIS INVESTIGATION IS CLOSED.ODI WILL CONTINUE TO MONITOR THE PROGRESSION OF THE NEW RECALL BEING CONDUCTED BY MCI.

An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.