MACK U Recalls

May 06, 1980 – ON CERTAIN VEHICLES, THE KNOB THAT OPERATES THE TRACTOR PARK VALVE MAY BREAK OFF, RENDERING THE VALVE INOPERABLE.

May 06, 1980 – THE PREFABRICATED PINCH BOLT CLAMP AT THE LOWER STEERING SHAFT LOWER YOKE MAY NOT PERFORM ADEQUATELY WHEN TIGHTENED TO SPECIFICATIONS. THE CLAMP MAY THEN DEFORM AND LOSS OF CLAMPING FORCE AND STEERING SHAFT DISENGAGEMENT MAY RESULT.

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.

Apr 03, 1979 – AN IMPROPER PINCH BOLT AND NUT MAY HAVE BEEN USED IN THE CLAMPING OF THE STEERING SHAFT TO THE STEERING GEAR INPUT SHAFT. DUE TO CLAMPING FORCE LOADS APPLIED AT THE BOLT, THE NUT COULD YIELD, RESULTING IN LOOSENESS OF THE INPUT SHAFT YOKE. SHOULD THIS CONDITION GO UNNOTICED, SPLINE WEAR COULD CAUSE SHAFT SEPARATION.

Jan 12, 1979 – A CASTING DEFICIENCY EXISTS IN THE LOWER SECTION OF THE CAPS RESULTING IN A REDUCTION IN THE THICKNESS OF THE MATERIAL. FAILURE OF A CAP CAN ALLOW THE END OF THE REAR SPRING TO DETACH FROM THE AXLE HOUSING.

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.