In response to an information request (ir) letter sent by the Office Of Defects Investigation (ODI), Ford stated that the primary cause for the majority of the reported front differential/drive shaft failures is a misalignment of the joint between the two components.certain levels of misalignment may over time cause an uneven wear of the splines.continued wear of the splines may result in a shearing of the splines and the inability of the driveshaft to transfer torque to the front differential. To address the issue in the field, Ford initiated a service campaign in June 2003 to correct the misalignment issue and, if necessary, replace the front drive shaft and/or differential.the service campaign covered model year (MY) 2003 and MY 2004 vehicles built from April 18, 2002 through July 3, 2003.in production, Ford introduced a change to the lubricating grease of the joint in February 2003 and a change to the assembly plant alignment process in July 2003 to address the misalignment and wear issue. ODI identified one crash related to the alleged defect.the crash involved a subject vehicle being struck in the rear after becoming disabled by a front differential/driveshaft failure and pulling to the side of the road. This preliminary evaluation has been upgraded to an engineering analysis (EA07-012) to further assess the scope, frequency and safety consequences of front differential/driveshaft failures in the subject vehicle population.
