Recalls for 1991 Mack Ch

DEFECT #1 - TRAILER HITCHES:FIFTH WHEEL ASSEMBLY

Posted on: 2000-05-11
Description
Vehicle description: heavy duty class 8 trucks equipped with fontaine fifth wheel assemblies.  The fifth wheel mounting plates can crack.

Consequence
Under the trailer loading, the mounting plate could eventually fail due to fatigue.

Corrective Action
Dealers will inspect and replace the mounting plates that are cracked.

Notes
Mack recall no.  Sco259.owner notification began june 22, 2000.owner notification is expected to begin owners who take their vehicles to an authorized dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should contact mack at 1-610-709-3011.  Also contact the national highway traffic safety administration's auto safety hotline at 1-888-dash-2-dot (1-888-327-4236).

DEFECT #2 - POWER TRAIN:DRIVELINE:CENTER SUPPORT BEARING

Posted on: 1994-11-22
Description
The driveshaft center bearing support bracket can crack and break.

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.

Corrective Action
Dealers will replace the center bearing hanger bracket.

Notes
System: powertrain; driveline; bracket; support; center shaft.vehicle description: class 8 heavy trucks.note: if the vehicle is presented to an authorized dealer on an agreed upon service date and the remedy is not provided free of charge within a reasonable time or the remedy does not correct the defect, contact mack trucks at 1-610-439-3011.  Also, contact the national highway traffic safety adminstration's auto safety hotline at 1-800-424-9393.

DEFECT #3 - VEHICLE SPEED CONTROL

Posted on: 1994-03-01
Description
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
In the event the primary throttle return fails, failure of the secondary throttle return system would not provide protection against loss of throttle control.

Corrective Action
A new production secondary throttle return system configuration will be installed.

Notes
System: fuel; fuel pump.vehicle description: class 8 trucks equipped with e6 and e7 engines with robert bosch p7100 mechanically-governed fuel injection pumps.note: if your vehicle is presented to an authorized dealer on an agreed upon service date and the remedy is not provided within a reasonable time and free of charge or the remedy does not correct the defect or noncompliance, please contact the national highway traffic safety administration's auto safety hotline at 1-800-424-9393.

DEFECT #4 - ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN

Posted on: 1993-09-01
Description
The engine cooling fan blades may break due to inadequate blade strength around the rivets that attach the blades to the fan spider.

Consequence
If complete fracture of the fan blade occurs, it couldbe propelled outside the fan shroud, injuring person(s) in the vicinity ofthe truck.

Corrective Action
An improved fan will be installed on these vehicles.

Notes
System: engine; cooling fan.vehicle description: class 8 heavy trucks equipped with 6 bladed fansmanufactured by engineered cooling systems, inc.

DEFECT #5 - SEAT BELTS:FRONT:ANCHORAGE

Posted on: 1991-06-28
Description
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


Corrective Action
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.

Notes
System: safety belt anchorages; fmvss 210.vehicle description: heavy trucks.