1990 Mack Ch recalls

VEHICLE DESCRIPTION: HEAVY DUTY CLASS 8 TRUCKS EQUIPPED WITH FONTAINE FIFTH WHEEL ASSEMBLIES. THE FIFTH WHEEL MOUNTING PLATES CAN CRACK.

UNDER THE TRAILER LOADING, THE MOUNTING PLATE COULD EVENTUALLY FAIL DUE TO FATIGUE.

DEALERS WILL INSPECT AND REPLACE THE MOUNTING PLATES THAT ARE CRACKED.

FUEL INJECTION SYSTEM RECONFIGURATION TO COMPLY WITH ENGINE EMISSION STANDARDS CAUSE HIGHER ENGINE VIBRATION LEVELS WHICH LEAD TO EARLY WEAR AND COMPLETE FAILURE OF THE SECONDARY THROTTLE RETURN MECHANISM.

IN THE EVENT THE PRIMARY THROTTLE RETURN FAILS, FAILURE OF THE SECONDARY THROTTLE RETURN SYSTEM WOULD NOT PROVIDE PROTECTION AGAINST LOSS OF THROTTLE CONTROL.

A NEW PRODUCTION SECONDARY THROTTLE RETURN SYSTEM CONFIGURATION WILL BE INSTALLED.

THE DRIVESHAFT CENTER BEARING SUPPORT BRACKET CAN CRACK AND BREAK.

IF THIS HAPPENS, THE DRIVESHAFT WILL WOBBLE AND CAN SEPARATE. SEPARATION CAN RESULT IN DAMAGE TO OTHER COMPONENTS OF THE VEHICLE OR LOOSE FRAGMENTS CAN FALL ONTO THE ROADWAY PRESENTING A HAZARD TO OTHER DRIVERS.

DEALERS WILL REPLACE THE CENTER BEARING HANGER BRACKET.

THE UPPER AND LOWER PINCH BOLT ON THE STEERING PITMAN ARM AND THE LOWER PINCH BOLT CONNECTION ON SHEPHARD POWER GEARS WERE NOT TORQUED CORRECTLY.

PINCH BOLT COULD LOOSEN AND BREAK; THIS COULD CAUSE LOSS OF TRUCK STEERING CONTROL AND RESULT IN A CRASH.

INSTALL ENGLISH HEX HEAD BOLTS AND FLAT WASHERS; TORQUE PINCH BOLTS TO SPECIFICATIONS.

LAP AND SHOULDER SEAT BELT ARRANGEMENT FOR FIXED (NON-SUSPENSION) SEATS DOES NOT MEET THE SEAT BELT LOADING REQUIREMENTS OF FMVSS 210. THE INBOARD CLINCH NUT IN CAB SILL, WHERE THE BUCKLE FOR THE SHOULDER AND LAP BELT IS MOUNTED, PULLED OUT OF THE SILL DURING THE TESTS. CONSEQUENCE OF DEFECT: IF SEAT BELT ANCHIRAGE FAILS, THE SEAT OCCUPANT FACES AN INCREASED RISK OF INJURY IN AN ACCIDENT OR SUDDEN STOP.

RELOCATE THE INBOARD SEAT BELT MOUNTING FROM TOP OF THE SILL TO THE FORWARD FLANGE OF THE SILL ON THE CAB FLOOR, AND ADD A 3MM FILLET WELD AROUND THE 2 INBOARD CLINCH NUTS.