Defect Investigation Detail

MCI / G4500 / 2000

Components - Details
NHTSA Action Number: RQ06008 Vehicale/Equipment Name: MCI
Vehicale/Equipment Model: G4500 Vehicale/Equipment Year: 2000
Component Name: SUSPENSION:FRONT:CONTROL ARM Manufacturer's Name: Motor Coach Industries
Date Opened: Sep, 05 2006 Date Closed: Jan, 17 2007
Subject: FAILED TAG AXLE SWING ARMS Summary: 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.