MACK R Recalls

Jul 09, 1979 – THE PINCH BOLT HOLE CENTER TO STEERING GEAR INPUT SHAFT ON THE LOWER YOKE DIMENSION EXCEEDS SPECIFICATIONS. IF THE PINCH BOLT BECOMES LOOSE, IT WILL NOT ENGAGE THE STEERING GEAR INPUT SHAFT NOTCH AND THE SHAFT COULD SLIP OFF.

Jun 01, 1979 – THE PITMAN ARM RETAINING NUT MAY NOT HAVE BEEN TORQUED TO MANUFACTURER SPECIFICATIONS. THIS COULD RESULT IN INADEQUATE RETENTION OF THE NUT AT THE OUTPUT SHAFT, ALLOWING THE PITMAN ARM TO BECOME LOOSE.

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.

May 30, 1979 – IN THE INVOLVED TRUCKS IT IS POSSIBLE THE ADJUSTABLE STEERING COLUMN REAR MOUNTING BRACKET COULD FAIL, ALLOWING STEERING WHEEL ASSEMBLY TO FALL DOWN ONTO THE OPERATOR"S LAP.

May 30, 1979 – IT HAS BEEN DETERMINED THAT TWO SCREWS THAT ARE PART OF THE BEARING ASSEMBLY LOCATED AT THE CAB DASH SHEET MAY NOT HAVE BEEN TIGHTENED PROPERLY. AS A RESULT, THE UPPER STEERING SHAFT MAY BE FREE TO "FLOAT" THROUGHOUT MUCH OF ITS LENGTH WHICH MAY RESULT IN INADEQUATE ENGAGEMENT IN THE SLIP SPLINES OF THE LOWER STEERING SHAFT. AXLE ARTICULATION COULD RESULT IN DISENGAGEMENT OF THE LOWER STEERING SHAFT SLIP SPLINES.

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.

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 11, 1978 – A SHORT CIRCUIT COULD OCCUR DUE TO CHAFING OR WIRE DISCONNECTION IN THE BOX.

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".