THESE VEHICLES HAVE FRONT AXLES WITH BRAKE CAM OPERATION OPPOSITE TO THE ROTATION OF THE BRAKE DRUM (CAM OPPOSITE), AND THERE IS A TENDENCY FOR BRAKES TO CHATTER UNDER LOW AIR PRESSURE, RESULTING IN VIBRATIONS. THE VIBRATIONS INDUCE STRESSES IN THE TIE ROD END BEYOND ITS ENDURANCE LIMIT, AND RESULT IN CRACKS IN THE THREADED PORTION OF THE STUD WHERE THE TUBE ENDS.
CRACKS IN THE TIE ROD CAN RESULT IN SEPARATION OF THETIE ROD AND LOSS OF VEHICLE CONTROL WITHOUT PRIOR WARNING.
REPLACE THE CAM OPPOSITE BRAKE ACTUATION WITH CAM SAME BRAKE OPERATION, BY INTERCHANGING THE LEFT AND RIGHT CAM ASSEMBLIES TO AVOID BRAKE CHATTERING; AND REPLACE TIE RODS.
SYSTEM: BRAKES AND FRONT SUSPENSION.VEHICLE DESCRIPTION: HEAVY TRUCKS WITH 18000 LBS. DRIVING FRONT AXLES.