NHTSA Preliminary Evaluation PE96052

CONSUMER COMPLAINTS REPORT THAT BOLTS WHICH RETAIN THE AXLE PIVOT BRACKET TO THE FRAME CROSS MEMBER CAN LOOSEN OR FAIL, CAUSING THE INBOARD END OR THE AXLE TO BECOME DETACHED FROM THE VEHICLE.OWNERS ALLEGE THAT THIS COULD RESULT IN LOSS OF STEERING CONTROL, HOWEVER THE COMPLAINT DATA SHOWS ONLY ONE INCIDENT WHERE THE VEHICLE LEFT THE ROADWAY FOLLOWING AXLE SEPARATION, WITH NO DAMAGE TO THE VEHICLE.IN ADDITION TO THE 225 CONSUMER COMPLAINTS, THERE WERE 4,315 WARRANTY CLAIMS RELATED TO THE FRONT SUSPENSION AND MEMBERS, AND 22 VEHICLES WERE REPLACED FOR GOODWILL.DOCUMENTS SUBMITTED BY FORD, UNDER REQUEST FOR CONFIDENTIAL TREATMENT INDICATE THAT THE BOLTS WERE INADEQUATE FOR THE DURABILITY REQUIREMENTS OF THE VEHICLE.ALSO, BOLTS WERE FOUND TO HAVE BEEN INADEQUATELY TORQUED AT ONE OR MORE ASSEMBLY PLANTS.OTHER FACTORS, SUCH AS WAX TREATMENT OF THE FRAME, CONTRIBUTED TO THE PROBLEM.INCREASED BOLT DIAMETER AND INCREASED TORQUE APPARENTLY CORRECTED THE PROBLEM.A SERVICE BULLETIN, 96-20-13, WAS ISSUED TO ADVISE DEALERS OF THIS CORRECTIVE ACTION.IN THESE DOCUMENTS, FORD ALSO REPORTED THAT A VEHICLE, EQUIPPED FOR SIMULTANEOUS CATASTROPHIC FAILURE OF ALL PIVOT BRACKET FASTENERS, WAS EVALUATED RESULTING IN A SLIGHT VEHICLE PULL TO ONE SIDE WITH NO LOSS OF VEHICLE CONTROL.ODI HAS NOT REPLICATED FORD'S VEHICLE TESTING, HOWEVER ANALYSIS OF THE DESIGN OF THE FRONT SUSPENSION INDICATES THAT EVEN IF THE INBOARD END OF THEAXLE BECAME DISCONNECTED FROM THE FRAME, THE OUTBOARD END WOULD REMAIN FIRMLY ATTACHED TO THE LEAF SPRING WITH TWO U-BOLTS.THIS WOULD RETAIN THE WHEEL IN ITS APPROXIMATE POSITION, ALTHOUGH THE WHEEL ALIGNMENT WOULD BE GREATLY IN ERROR.THEREFORE IT IS UNLIKELY THAT CONTROL OF THE VEHICLE WOULD BE LOST.OWNERS REPROT MANY SIGNIFICANT NOISES IN THE SUSPENSION, SUCH AS CREAKING, GROANING, CLUNKING, AND SQUEAKING, PRIOR TO NOTICING ANY SEPARATION OF THE AXLE.THIS PROVIDES WARNING OF THE LOOSENING OF THE BOLTS TO THE DRIVER, AND SHOULD NOT BE IGNORED.FORD HAS STATED THAT REP