1983 Mack MH recalls

DUE TO IMPROPER AND INADEQUATE WELDING PRACTICES, THE FIFTH WHEEL ON THE INVOLVED VEHICLES IS DEFECTIVE. FRAME MOUNTED SUPPORTS MAY HAVE INCOMPLETE OR POOR QUALITY WELDS. THE WELDS COULD SUBSEQUENTLY FAIL ALLOWING SEPARATION OF THE TRACTOR FROM THE TRAILER.

Remedy

THE DEALER WILL INSPECT AND REMOVE THE FIFTH WHEEL AND REWELD THE MOUNTING ANGLES AT NO CHARGE TO THE OWNER.

VEHICLE DESCRIPTION: TRUCK TRACTORS.SYSTEM: STRUCTURE; FIFTH WHEEL ASSEMBLY.CONSEQUENCES OF DEFECT: IF THE TRAILER SEPARATES DURING OPERATION AN ACCIDENTAND PERSONAL INJURY COULD RESULT.

UNDER SEVERE STRAIN, A DEFECTIVE WELD JOINING THE STEERING WHEEL HUB TO THE HUB PERIMETER COULD FAIL, CAUSING THE STEERING WHEEL TO SEPARATE FROM THE VEHICLE.

Remedy

DEFECTIVE STEERING WHEELS WILL BE REPLACED AT NO CHARGE TO OWNER.

VEHICLE DESCRIPTION: TRUCKS.SYSTEM: STEERING; STEERING WHEEL HUB TO PERIMETER WELD.CONSEQUENCES OF DEFECT: SEPARATION OF THE STEERING WHEEL WOULD PROBABLY CAUSELOSS OF VEHICLE CONTROL WITHOUT WARNING, POSSIBLY RESULTING IN AN ACCIDENT.NOTE: THE TRUCK SHOULD NOT BE DRIVEN UNTIL THE DEFECTIVE STEERING WHEEL ISCORRECTED.

THE DUAL DOUBLE CHECK VALVE MAY NOT RELEASE THE PROPER AIR VOLUME TO THE BRAKE SYSTEM, CAUSING A SLIGHT TIMING DELAY BETWEEN THE TRACTOR AND THE TRAILER BRAKE SYSTEM. CONSEQUENCES OF DEFECT: IF THE BRAKES ARE SUDDENLY APPLIED, THE TRAILER COULD JACKKNIFE WITHOUT WARNING TO THE OPERATOR, WHICH COULD RESULT IN A VEHICLE CRASH.

Remedy

INSTALL TWO NEW SLEEVES IN THE DUAL DOUBLE CHECK VALVE WHICH WILL INCREASE AIR FLOW.

VEHICLE DESCRIPTION: HEAVY DUTY TRACTOR TRAILER COMBINATIONS. SYSTEM: BRAKES, TRACTOR TO TRAILER.

SEAT TETHER BELTS MAY NOT HAVE BEEN ADJUSTED DURING ASSEMBLY.

Consequence

DURING AN IMPACT, DRIVER AND/OR RIDER CAN MOVE FORWARDAND POSSIBLY STRIKE THE WINDSHIELD, EVEN WHEN WEARING A SEAT BELT.

Remedy

ADJUST SEAT TETHER BELT IF NECESSARY.

SYSTEM: SEAT TETHER BELT.VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS WITH AIR SUSPENSION SEATS.

THE FLIP OUT STEP CLEVIS ON THE BUMPER MAY FAIL AND BREAK UNDER THE WEIGHT OF THE PERSON STANDING ON THE STEP TO SERVICE THE FRONT AREA OF THE VEHICLE. CONSEQUENCE OF DEFECT: THIS SUDDEN BREAK WILL CAUSE THE PERSON STANDING ON THE STEP TO FALL, WITHOUT WARNING, AND COULD RESULT IN INJURIES.

Remedy

REMOVE THE STEP CLEVIS AND REPLACE WITH A NEW IMPROVED CLEVIS.

VEHICLE DESCRIPTION: HEAVY DUTY ULTRALINER TRUCKS. SYSTEM: BUMPER FLIP OUT STEP CLEVIS.

A MANUFACTURING ERROR RESULTED IN THE INSTALLATION OF CARBON STEEL SPRINGS IN SOME DUAL-COMPARTMENT AIR RESERVOIR CHECK VALVES. CARBON STEEL SPRINGS ARE INADEQUATE FOR THIS APPLICATION BECAUSE THEY ARE SUBJECT TO SEVERE CORROSION AND SUBSEQUENT FAILURE OF THE CHECK VALVE.

Remedy

THE CARBON STEEL SPRING WILL BE REPLACED WITH A STAINLESS STEEL ONE.

VEHICLE DESCRIPTION: HEAVY TRUCKS.SYSTEM: SERVICE BRAKES; DUAL COMPARTMENT AIR RESERVOIR CHECK VALVE.CONSEQUENCES OF DEFECT: IF THIS CHECK VALVE FAILURE WERE COMBINED WITH ASEVERED LINE IN THE PRIMARY AIR SYSTEM, COMPLETE LOSS OF BRAKES AND POSSIBLEVEHICLE CRASH COULD OCCUR.

IMPROPER STEERING CLAMP BOLTS AND TORQUE APPLIED DURING INSTALLATION. THE BOLT COULD FAIL, ALLOWING THE STEERING YOKE TO BECOME LOOSE.

Remedy

INSPECTION AND, IF NECESSARY, INSTALLATION OF PROPER STEERING SHAFT CLAMP BOLTS TIGHTENED TO SPECIFICATIONS.

VEHICLE DESCRIPTION: HEAVY TRUCKS.SYSTEM: STEERING; SHAFT CLAMP BOLTS.CONSEQUENCES OF DEFECT: THIS CAN LEAD TO COMPLETE LOSS OF STEERING CONTROLWITHOUT WARNING AND POSSIBLE VEHICLE CRASH.

LEFT OR RIGHT CAB STEP MAY CRACK IN ITS WELDED AREA DUE TO FLEXING OF THE STEP DURING ENTERING AND EXITING. CONSEQUENCE OF DEFECT: AS THE CRACKS EXTEND, THE TUBULAR STEP COULD PARTIALLY COLLAPSE AND BREAK WITHOUT WARNING TO THE USER, AND COULD RESULT IN PERSONAL INJURIES.

Remedy

INSTALL A REINFORCEMENT BRACE IF NO CRACKS ARE FOUND. IN ADDITION, REPLACE STEP IF CRACKS ARE PRESENT.

SYSTEM: CAB STEP. VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS WITH SLEEPER CAB.