1977 Mack U Recalls

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NHTSA Campaign Number: 79V133000
Manufacturer: Mack Trucks, Inc.
Manufactured Begin Date: February 1st, 1977
Manufactured End Date: March 1st, 1979
Date of Owner Notification: November 2nd, 1979

Defect Summary:
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.

Corrective Summary:
DEALER WILL INSTALL A SHIELD FOR THE HEADS OF THE FOUR CAPSCREWS, ALONG WITH STRONGER SAE 8 GRADE 8 CAPSCREWS, IF NECESSARY, AT NO COST TO OWNER.

Recall Notes:
VEHICLE DESCRIPTION: TRUCKS EQUIPPED WITH ENDT (B) 676, ETAZ (B) 673A, AND ETAY(B) 673A ENGINES.SYSTEM: ENGINE AND ENGINE COOLING.CONSEQUENCES OF DEFECT: ENGINE LUBRICATING OIL, IN THE PRESENCE OF A SOURCE OFIGNITION, COULD LEAD TO AN ENGINE COMPARTMENT FIRE AND SERIOUS INJURY TOVEHICLE PASSENGERS.

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NHTSA Campaign Number: 78V210000
Manufacturer: Mack Trucks, Inc.
Manufactured Begin Date: October 1st, 1977
Manufactured End Date: September 1st, 1978
Date of Owner Notification: November 7th, 1978

Defect Summary:
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".

Corrective Summary:
DEALER WILL INSTALL NEW WHEEL SPEED SENSORS THAT INCORPORATE IMPROVED WIRING AND THE PRESENT BOGIE ANTI-WHEEL LOCK SYSTEM WILL BE CHANGED TO AN AXLE-TO-AXLE SYSTEM FOR IMPROVED RELIABILITY.

Recall Notes:
VEHICLE DESCRIPTION: HEAVY TRUCKS.SYSTEM: SERVICE BRAKES; ELECTRICAL WIRING AND CONNECTORS.CONSEQUENCES OF DEFECT: THIS DELAY IN EFFECTIVE BRAKING ACTION COULD LEAD TO ANACCIDENT UNDER CERTAIN TRAFFIC CONDITIONS.

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NHTSA Campaign Number: 78V031000
Manufacturer: Mack Trucks, Inc.
Manufactured Begin Date: March 1st, 1975
Manufactured End Date: February 1st, 1978
Date of Owner Notification: August 16th, 1978

Defect Summary:
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.

Corrective Summary:
THE DEALER WILL REPLACE THE DEFECTIVE BRACKET WITH A REDESIGNED VERSION.

Recall Notes:
VEHICLE DESCRIPTION: TRUCKS EQUIPPED WITH HIGHWAY BOGIES.SYSTEM: SUSPENSION; TEE BRACKET.CONSEQUENCES OF DEFECT: AUTOMATIC APPLICATION OF THE SPRING EMERGENCY BRAKESCOULD CAUSE LOSS OF VEHICLE CONTROL AND AN ACCIDENT.

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NHTSA Campaign Number: 77V173000
Manufacturer: Mack Trucks, Inc.
Date of Owner Notification: March 23rd, 1978

Defect Summary:
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.

Corrective Summary:
DEALER WILL REPLACE THE ORIGINAL FAN WITH A STEEL FIXED BLADE FAN, FREE OF CHARGE.

Recall Notes:
VEHICLE DESCRIPTION: TRUCKS EQUIPPED WITH SIX-CYLINDER ENGINES.SYSTEM: ENGINE COOLING; FAN.CONSEQUENCES OF DEFECT: BROKEN PIECES CAN BE PROPELLED OUTSIDE OF THE FANSHROUD AND WILL PRESENT AN IMMEDIATE DANGER AND POSSIBLE INJURY TO PERSONSSTANDING NEARBY.NOTE: PRIOR TO CORRECTION, VEHICLE SHOULD NOT BE SERVICED WITH THE HOOD RAISEDAND THE ENGINE RUNNING.

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NHTSA Campaign Number: 79V082000
Manufacturer: Mack Trucks, Inc.
Manufactured Begin Date: March 1st, 1977
Manufactured End Date: November 1st, 1978
Date of Owner Notification: August 13th, 1979

Defect Summary:
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.

Corrective Summary:
VEHICLES WILL BE INSPECTED AND, IF NECESSARY, THE CORRECT FASTENERS WILL BE INSTALLED AT NO CHARGE TO OWNER.

Recall Notes:
VEHICLE DESCRIPTION: HEAVY TRUCKS.SYSTEM: STEERING; STEERING SHAFT CLAMP BOLT.CONSEQUENCES OF DEFECT: THIS DEFECT COULD CAUSE LOSS OF VEHICLE CONTROL AND AVEHICLE ACCIDENT.

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NHTSA Campaign Number: 77V174000
Manufacturer: Mack Trucks, Inc.
Date of Owner Notification: August 23rd, 1978

Defect Summary:
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.

Corrective Summary:
DEALER WILL INSPECT AND, IF NECESSARY, REPLACE SEAT BELT ASSEMBLIES WITHOUT CHARGE TO OWNER.

Recall Notes:
VEHICLE DESCRIPTION: TRUCKS.SYSTEM: INTERIOR; SEAT BELT ANCHORAGE ASSEMBLY.CONSEQUENCES OF DEFECT: IN THE EVENT OF AN ACCIDENT, THESE SEAT BELTS MAY NOTADEQUATELY RESTRAIN PASSENGERS AND SERIOUS INJURIES MAY RESULT.

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NHTSA Campaign Number: 77V205000
Manufacturer: Mack Trucks, Inc.
Manufactured Begin Date: May 1st, 1977
Manufactured End Date: October 1st, 1977
Date of Owner Notification: March 14th, 1978

Defect Summary:
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.

Corrective Summary:
DEALER WILL REWELD THE INSULATOR SPRING BRACKET AT NO COST TO OWNER.

Recall Notes:
VEHICLE DESCRIPTION: HEAVY TRUCKS.SYSTEM: SUSPENSION; TANDEM AXLE.CONSEQUENCES OF DEFECT: THIS CONDITION COULD CAUSE A LOSS OF VEHICLE CONTROLAND A VEHICLE ACCIDENT.

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NHTSA Campaign Number: 79V017000
Manufacturer: Mack Trucks, Inc.
Manufactured Begin Date: January 1st, 1977
Manufactured End Date: December 1st, 1978
Date of Owner Notification: August 13th, 1979

Defect Summary:
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.

Corrective Summary:
DEALER WILL INSPECT AND, IF NECESSARY, REPLACE ANY OF THE SPRING INSULATOR CAPS FOUND TO BE DEFECTIVE. THIS WILL BE DONE AT NO COST TO OWNER.

Recall Notes:
VEHICLE DESCRIPTION: TRUCKS, HEAVY.SYSTEM: SUSPENSION; INSULATOR CAP.CONSEQUENCES OF DEFECT: LOSS OF VEHICLE CONTROL CAN RESULT AND LEAD TO AVEHICLE ACCIDENT.