THE DRIVESHAFT CENTER BEARING SUPPORT BRACKET CAN CRACK AND BREAK.
Consequence & remedy
Consequence: 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.
Remedy: DEALERS WILL REPLACE THE CENTER BEARING HANGER BRACKET.
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.
Consequence & remedy
Consequence: IN THE EVENT THE PRIMARY THROTTLE RETURN FAILS, FAILURE OF THE SECONDARY THROTTLE RETURN SYSTEM WOULD NOT PROVIDE PROTECTION AGAINST LOSS OF THROTTLE CONTROL.
Remedy: A NEW PRODUCTION SECONDARY THROTTLE RETURN SYSTEM CONFIGURATION WILL BE INSTALLED.
THE ENGINE COOLING FAN BLADES MAY BREAK DUE TO INADEQUATE BLADE STRENGTH AROUND THE RIVETS THAT ATTACH THE BLADES TO THE FAN SPIDER.
Consequence & remedy
Consequence: IF COMPLETE FRACTURE OF THE FAN BLADE OCCURS, IT COULDBE PROPELLED OUTSIDE THE FAN SHROUD, INJURING PERSON(S) IN THE VICINITY OFTHE TRUCK.
Remedy: AN IMPROVED FAN WILL BE INSTALLED ON THESE VEHICLES.
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.
Consequence & remedy
Consequence: Not supplied
Remedy: 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.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0
No exact-year investigations in this snapshot.
1991 Mack Ch Problems, Complaints & Recalls | Skip That Year