MACK F Recalls

Jul 12, 1979 – THE SPRING SEAT PLATE, LOCATED BETWEEN THE AXLE HOUSING AND THE SUSPENSION SPRINGS, MAY DEFORM DUE TO SPRING BENDING. AS A RESULT, THE CLAMPING FORCE IN THE ASSEMBLY MAY BE REDUCED. LOSS OF CLAMPING FORCE COULD CAUSE SPRING FAILURE AND THE AXLE WILL DISLOCATE. ALSO, THE TIRE COULD COME INTO CONTACT WITH THE SPRING.

May 31, 1979 – IN THE EVENT OF TURBOCHARGER COMPRESSOR WHEEL FAILURE, ONE OR MORE OF THE FOUR CAPSCREWS THAT HOLD THE TURBOCHARGER TOGETHER MAY BE STRUCK BY PARTS OF THE COMPRESSOR WHEEL, RESULTING IN THE CAPSCREWS BEING DAMAGED. IF THESE CAPSCREWS ARE DAMAGED TO THE POINT THAT THEY ALLOW THE COMPRESSOR BACK PLATE TO DISLOCATE FROM THE TURBOCHARGER BEARING HOUSING, ENGINE LUBRICATING OIL MAY BE ALLOWED TO ESCAPE UNDER PRESSURE, CONTACTING THE ENGINE EXHAUST MANIFOLD SECTIONS OR TURBOCHARGER TURBINE HOUSING.

Jan 12, 1979 – THE STEEL BRACKETS ON THE SUSPENSION BEAM WERE FOUND TO BE DEFICIENT DUE TO EXCESSIVE SHRINKAGE AND LOW MECHANICAL PROPERTIES. FAILURE OF ONE OR BOTH OF THESE BRACKETS COULD CAUSE A SEPARATION OF THE AXLE HOUSING FROM THE SUSPENSION.

Oct 03, 1978 – DELAYS OF UP TO ABOUT 2 SECONDS MAY EXIST IN THE BRAKE APPLICATION TIMES TO THE BRAKES ON THE BOGIE AXLES IN THE PRESENCE OF CERTAIN TYPES OF WHEEL SPEED SENSOR SIGNAL DISCONTINUITIES OR DISTORTIONS THAT MAY OCCUR AS A RESULT OF SENSOR WIRE FAILURE. THIS CONSTITUTES A NON-COMPLIANCE TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121, "AIR BRAKE SYSTEMS".

Aug 08, 1978 – DEFICIENCIES, IN THE FORM OF FORGING LAPS, CRACKS AND EXCESSIVE DECARBURIZATION DURING HEAT TREATMENT, EXIST IN THE STEERING KNUCKLES. STRESSES IMPOSED WITH INTEGRAL HYDRAULIC POWER STEERING MAY LEAD TO A FAILURE IN THE AREA OF THE STEERING ARM ATTACHING BOSS. THIS TYPE OF FAILURE WOULD CAUSE LOSS OF STEERING CONTROL.

Apr 04, 1978 – AN AXLE "NO BRAKE" CONDITION COULD RESULT FROM AN EATON CONTROLLER INTERNAL ELECTRICAL MALFUNCTION. THIS CONDITION MAY CAUSE THE ANTI-WHEEL LOCK VALVE SOLENOID TO BE CONTINUOUSLY ENERGIZED AND PREVENT THE BRAKES FROM BEING APPLIED ON ONE OF THE AXLES. AS A RESULT, THE ANTI-WHEEL LOCK WARNING LAMP IS NOT ACTIVATED.

Feb 09, 1978 – THE TEE BRACKET, WHICH IS MOUNTED ON THE FRONT AXLE OF THE BOGIE, MAY FAIL DUE TO VIBRATION BROUGHT ON BY ROAD SURFACE IRREGULARITIES. BRACKET FAILURE WOULD LEAVE THE TEE BRACKET UNSUPPORTED AND CAUSE BROKEN HOSE CONNECTOR FITTINGS. THIS WOULD RESULT IN AUTOMATIC APPLICATION OF THE SPRING EMERGENCY BRAKES.

Nov 21, 1977 – A DEFICIENCY EXISTS IN THE WELDS SECURING THE REAR SPRING INSULATOR BRACKET TO THE AXLE HOUSING. THIS IS DUE TO IMPROPER POSITIONING OF THE WELD, IN RELATIONSHIP TO THE BRACKET AND AXLE HOUSING. FAILURE OF THE WELDS WOULD CAUSE SEPARATION OF THE SPRING INSULATOR BRACKET AND THE AXLE HOUSING, RESULTING IN IMPROPER ALIGNMENT OF THE AFFECTED AXLE.

Oct 12, 1977 – THE FLEX BLADE FANS ON THE INVOLVED VEHICLES MAY DEVELOP CRACKS IN THE LAMINATED STIFFENER AS A RESULT OF FATIGUE DURING OPERATION. IF SUCH A CONDITION EXISTS AND THE CRACKS GO UNDETECTED, CONTINUED OPERATION COULD CAUSE PIECES OF THE STIFFENER TO BREAK OFF.

Oct 12, 1977 – THE INVOLVED VEHICLES DO NOT CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 209, "SEATBELT ASSEMBLIES". ALTHOUGH THE SEATBELTS IN QUESTION PERFORMED MARGINALLY WITH RESPECT TO THE 5000 LB. LOAD REQUIREMENT, ADDITIONAL TESTING CONFIRMED THAT THE ANCHOR COULD FAIL, ALLOWING EITHER THE ANCHOR TO SLIP OVER THE HOLD-DOWN NUT OR THE ANCHOR TO SEPARATE INTO TWO PIECES.