NHTSA Complaint #10174057 — 2005 FREIGHTLINER CENTURY CLASS

THE AIR FORCE LOST A SEMI TRUCK-TRACTOR IN A VEHICLE FIRE ON 6/30/2006. THE VEHICLE, A 2005 FREIGHTLINER CENTURY CLASS TRACTOR, WAS LEASED FROM GENERAL SERVICES ADMINISTRATION. A SEMI-TRAILER OWNED BY THE AIR FORCE WAS ALSO DESTROYED. THE VEHICLE DEPARTED TRAVIS AFB, CA AROUND 1115L ON 6/30/2006. AFTER THE OPERATOR SMELLED AN ELECTRICAL BURNING ODOR. AS HE PULLED OFF ONTO THE RIGHT SHOULDER. OPENING THE HOOD, HE SAW FIRE IN THE AIR CLEANER. HE RETRIEVED THE FIRE EXTINGUISHER TO PUT OUT THE FLAMES BUT THE FIRE REGAINED INTENSITY AND SPREAD THROUGHOUT THE ENGINE COMPARTMENT. THE HIGHWAY PATROL/FIRE DEPARTMENT ARRIVED ON SCENE AT 1156L AND 1204L RESPECTIVELY. SAFETY INVESTIGATION REVEALED THE FIRE IGNITED WHEN THE BATTERY CABLE ARCED ON THE RIGHT FRONT LEAF SPRING DUE TO LOOSE WIRE HANGERS. TWO BOLTS ON THE TRANSMISSION HOLD THE BRACKETS THAT SUPPORT THE MAIN BATTERY CABLE/ALTERNATOR CABLE. THE LOOSE BOLTS ALLOWED THE MAIN BATTERY CABLE/ALTERNATOR CABLE TO HAVE SIGNIFICANT MOVEMENT ON THE UNDERSIDE OF THE TRANSMISSION. INVESTIGATORS FOUND THE TWO INCH LONG TRANSMISSION/HANGER BOLT ON THE LEFT SIDE WAS BACKED OUT 1/2 INCH AND THE BOLT ON THE RIGHT WAS BACKED OUT 1/4 INCH. A ONE-TIME INSPECTION (OTI) OF ALL SIMILAR TRUCKS DISCOVERED FOUR ADDITIONAL TRACTORS WITH LOOSE BATTERY CABLES/CLAMPS. ROOT CAUSE OF THE PROBLEM IS AT THE BELL-HOUSING AND HOW THE BRACKET WHERE THE BATTERY CABLES ATTACH IS SECURED TO THE TRANSMISSION. A MINOR REPAIR IS NEEDED TO FIX THE DEFECT. BECAUSE THE BELL-HOUSING BOLT HOLES ARE COUNTERSUNK AND CIRCULAR, THE BRACKET WHICH SECURES THE BATTERY CABLES CANNOT BE MOUNTED FLUSH WITH THE BELL-HOUSING. THIS CAUSES THE BELL-HOUSING BOLT TO BACK OUT AND LET THE BRACKET HANG LOOSE. THE SOLUTION: ADD ANOTHER FLAT WASHER BEHIND THE BRACKET TO ALLOW IT TO SIT FLUSH, AND ADD A LOCK WASHER TO THE FRONT OF THE BRACKET TO PREVENT IT FROM LOOSENING. THE FIX TAKES ABOUT 15 MINUTES PER VEHICLE. *JB