EQUIPMENT DESCRIPTION: ANTILOCK BRAKING SYSTEM (ABS) ELECTRONIC CONTROL UNITS (ECU) FOR OVER-THE-ROAD TRAILER APPLICATIONS. THE COVER SEAL (O-RING) MAY HAVE BEEN IMPROPERLY INSTALLED IN CERTAIN EASY-STOP TRAILER ABS ELECTRONIC CONTROL UNITS. AN INCORRECTLY INSTALLED SEAL COULD PERMIT WATER TO ENTER THE ECU CAUSING A FAULT TO DEVELOP. THIS WILL CAUSE THE VEHICLE'S TRAILER ABS WARNING LAMP TO ILLUMINATE IMMEDIATELY WHEN THE WATER CONTACTS THE BOARD, DEACTIVATING ALL OR PART OF THE ABS.
DURING ASSEMBLY, THE TIE ROD END NUTS WERE NOT PROPERLY TORQUED. EXTREMELY LOW TORQUE CAN ALLOW MOVEMENT BETWEEN THE BALL STUD AND THE TIE ROD ARM CAUSING DAMAGE.
DURING ASSEMBLY, THE TIE ROD END NUTS WERE NOT PROPERLY TORQUED. EXTREMELY LOW TORQUE CAN ALLOW MOVEMENT BETWEEN THE BALL STUD AND THE TIE ROD ARM CAUSING DAMAGE.
DURING ASSEMBLY, THE TIE ROD END NUTS WERE NOT PROPERLY TORQUED. EXTREMELY LOW TORQUE CAN ALLOW MOVEMENT BETWEEN THE BALL STUD AND THE TIE ROD ARM CAUSING DAMAGE.
DURING ASSEMBLY, THE TIE ROD END NUTS WERE NOT PROPERLY TORQUED. EXTREMELY LOW TORQUE CAN ALLOW MOVEMENT BETWEEN THE BALL STUD AND THE TIE ROD ARM CAUSING DAMAGE.
DURING ASSEMBLY, THE TIE ROD END NUTS WERE NOT PROPERLY TORQUED. EXTREMELY LOW TORQUE CAN ALLOW MOVEMENT BETWEEN THE BALL STUD AND THE TIE ROD ARM CAUSING DAMAGE.
AIR SYSTEM BLOCKAGE IN THE AIR DRYER OCCURS DEGRADING THE MOISTURE REMOVING CAPABILITIES OF THE DRYER WHEN THE VEHICLE IS OPERATED IN A COLD ENVIRONMENT AND MOISTURE ACCUMULATES AND FREEZES IN THE AIR DRYER OR IN THE LINE BETWEEN THE DRYER AND THE AIR SYSTEM RESERVOIR. THE AIR DRYER CAN BECOME OVER PRESSURIZED CAUSING THE AIR DRYER CARTRIDGE TO SEPARATE FROM THE MOUNTING BASE.
AIR SYSTEM BLOCKAGE IN THE AIR DRYER OCCURS DEGRADING THE MOISTURE REMOVING CAPABILITIES OF THE DRYER WHEN THE VEHICLE IS OPERATED IN A COLD ENVIRONMENT AND MOISTURE ACCUMULATES AND FREEZES IN THE AIR DRYER OR IN THE LINE BETWEEN THE DRYER AND THE AIR SYSTEM RESERVOIR. THE AIR DRYER CAN BECOME OVER PRESSURIZED CAUSING THE AIR DRYER CARTRIDGE TO SEPARATE FROM THE MOUNTING BASE.
THE MACHINING PERFORMED ON THE BRAKE DRUMS WILL NOT PERMIT THE DRUM TO SEAT FULLY AGAINST THE HUB FACE. THE REDUCED BRAKE DRUM AND HUB CONTACT AREA WILL ABRADE AND FRET ALLOWING THE WHEEL MOUNTING JOINT TO LOOSEN.
THE MACHINING PERFORMED ON THE BRAKE DRUMS WILL NOT PERMIT THE DRUM TO SEAT FULLY AGAINST THE HUB FACE. THE REDUCED BRAKE DRUM AND HUB CONTACT AREA WILL ABRADE AND FRET ALLOWING THE WHEEL MOUNTING JOINT TO LOOSEN.
THE HIGH STRENGTH -- LOW ALLOY MATERIAL WHICH WAS USED IN THE TURNBUCKLE STYLE CROSS-TUBE AXLE ASSEMBLIES HAS LOW IMPACT RESISTANCE PROPERTIES. THE TURNBUCKLE STYLE CROSS-TUBE ASSEMBLIES ARE THEREFORE SUSCEPTIBLE TO FRACTURE UNDER IMPACT LOADS DUE TO THE COMPONENT'S DESIGN GEOMETRY AND THE LOW IMPACT RESISTANCE OF THE MATERIAL.
THE BRAKE ASSEMBLIES DO NOT MEET THE BRAKE POWER AND BRAKE RECOVERY SECTIONS OF FMVSS 121 AIR BRAKE SYSTEMS.
THE INTERAXLE DRIVELINE U-JOINTS MAY FAIL AT LOW MILEAGE DUE TO LACK OF LUBRICATION IN THE U-JOINT IN THE ASSEMBLY PROCESS.
AXLES MAY DEVELOP FATIGUE CRACKS IN AXLE SPINDLE THAT COULD PROPAGATE INTO A TRANSVERSE CRACK.
DUE TO OPERATIONAL CONDITIONS, STEERING ARMS COULD CRACK AND BREAK.
STEERING ARMS CRACK AND BREAK FROM PRESSURES EXERTED IN OPERATIONS IN URBAN TRAFFIC ENVIRONEMNTS.
IMPROPER HEAT TREATMENT OF TIE ROD ARMS CAUSES ARMS TO BE SUBJECT TO YIELDING AND FATIGUE CRACKS.
TRAILER AXLE ASSEMBLIES MAY CONTAIN SHOE AND LINING ASSEMBLIES THAT DO NOT COMPLY WITH THE BRAKE RETARDATION FORCE PERFORMANCE REQUIREMENTS OF FMVSS 121.
HUB MOUNTING FACE DIAMETER OF DRUM MAY BE IMPROPERLY MACHINED CAUSING A LINE CONTACT INTERFERENCE OF THE HUB AND DRUM ASSEMBLY, LOOSENING OF THE WHEEL NUT AND WHEEL STUD FRACTURE.
STEERING ARM MAY FRACTURE DUE TO ENVIRONMENTAL, MAINTENANCE, OR OTHER FACTORS.
A NUMBER OF FACTORS COULD CAUSE LONGITIDUNAL AND - OR TRANSVERSE CRACKS IN THE SPINDLE END THAT COULD LEAD TO SPINDLE END FAILURE AND SEPARATION OF WHEELS FROM VEHICLE.
INCORRECTLY WELDED SUSPENSION BRACKETS TO THE AXLE HOUSING MAY CAUSE PREMATURE FAILURE OF THE HOLDING BRACKET WELD.
FRACTURE OF THE SPINDLE END AND SEPARATION OF THE DUAL WHEELS FROM THE VEHICLE.
DUE TO METAL FATIGUE, CRACKING AND BREAKING OF THE FRONT AXLE BEAM CENTER COULD OCCUR.
ORIGINAL SPECIFIED REAR BRAKE DRUMS ARE INADEQUATE IN STRENGTH FOR BRAKE LOADS BEING IMPOSED ON THESE DRUMS.
THE SPRING HANGER BRACKET MAY CONTAIN INCORRECT WELDS.
THE BRAKE MOUNTING NUTS WHICH FASTEN THE TWO BRAKE ASSEMBLIES TO THE AXLE KNUCKLE ON THE FRONT STEERING AXLE ASSEMBLIES OR THE WHEEL END KITS WERE NOT PROPERLY TIGHTENED. CONSEQUENCE OF DEFECT: IF SUFFICIENT LOOSENING OF THE BRAKE ASSEMBLIES SHOULD OCCUR DURING VEHICLE MOVEMENT, BRAKE DRAG, POSSIBLE SEVERE HEAT BUILD-UP OR WHEEL LOCKUP COULD OCCUR, CAUSING DECREASED STEERING CONTROL, VEHICLE INSTABILITY AND A POTENTIAL FOR VEHICLE CRASH.
FRONT AXLE BEAMS CONTAIN SHEAR CRACKS AT THE BEAM ENDS WHERE THE KING PINS AND STEERING KNUCKLES ARE ATTACHED. CONSEQUENCE OF DEFECT: IF FAILURE OF THE AXLE BEAMS AS PART OF THE FRONT STEERING AXLE SHOULD OCCUR, THE COMPONENTS ATTACHED TO THE BEAMS INCLUDING WHEELS, TIRES, BRAKE ASSEMBLIES AND STEERING KNUCKLES MAY BECOME DISENGAGED FROM THE VEHICLE, AND ROLL FREE WITH A RISK TO TRAFFIC SAFETY. THE VEHICLE MAY LOSE STEERING CONTROL, CAUSING VEHICLE INSTABILITY AND POTENTIAL FOR VEHICLE CRASH. THIS FAILURE COULD OCCUR WITHOUT PRIOR WARNING TO THE OPERATOR.
THE INVOLVED VEHICLES DO NOT CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT. ALSO, POTENTIAL OVERLOADING OF THE VEHICLE MAY OCCUR DUE TO INADEQUATE AXLE SPRINGS WHICH WOULD NOT PROPERLY EQUIP THE VEHICLE FOR HIGHWAY DRIVING.