1999 Navistar 4700 problems

Defect

VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS BUILT WITH REAR LEAF SPRING SUSPENSIONS (MODELS 4700 BUILT WITH REAR LEAF SUSPENSIONS AND MANUFACTURED FROM DECEMBER 9, THROUGH DECEMBER 16, 1998; MODELS 3400 AND 3800 BUILT WITH 14SBK REAR LEAF SPRING SUSPENSIONS AND BUILT APRIL 14 THROUGH MAY 10, 1999; AND MODELS 3400 AND 3800 BUILT WITH REAR LEAF SPRING SUSPENSIONS AND MANUFACTURED FROM MAY 10 THROUGH MAY 18, 1999). ON VEHICLES WHERE THE FRAME TO AXLE HOSE LENGTH WAS TOO LONG, A CHAFING CONDITION EXISTS ON SUSPENSION COMPONENTS, WHICH COULD RESULT IN HOSE RUPTURE. ON VEHICLES WHERE THE HOSES ARE TOO SHORT, A HOSE SEPARATION COULD OCCUR WITH SEVERE SUSPENSION ARTICULATION.

Consequence

IF A HOSE RUPTURES, THE REAR BRAKES WILL FAIL INCREASING THE RISK OF A VEHICLE CRASH.

Remedy

SHORT HOSES WILL BE REPLACED AND THE LONG HOSES WILL HAVE A HOSE ROUTING KIT INSTALLED TO PREVENT ANY CHAFING PROBLEMS.

Defect

VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS, TRANSIT AND SCHOOL BUSES, EQUIPPED WITH MERITOR AIR BRAKE AUTOMATIC SLACK ADJUSTERS. SOME OF THE AUTOMATIC SLACK ADJUSTERS HAD INSUFFICIENT TORQUE APPLIED TO THE GUIDE PAWL CAP SCREW.

Consequence

WITHOUT SUFFICIENT TORQUE ON THE GUIDE PAWL CAP SCREW, THE BRAKES COULD GRADUALLY LOSE ADJUSTMENT, INCREASING THE VEHICLE STOPPING DISTANCE.

Remedy

DEALERS WILL CHECK THE TORQUE ON THE AUTOMATIC SLACK ADJUSTER GUIDE PAWL. IF THERE IS NO TORQUE, THE BRAKES WILL BE ADJUSTED AND THE GUIDE PAWL WILL BE TIGHTENED TO 15-20 FT. LBS.

Defect

VEHICLE DESCRIPTION: CLASS 8 HEAVY DUTY TRUCK CHASSIS EQUIPPED WITH 16,000 LB., 18,000 LB., OR 20,000 LB. HEAVY DUTY STEERING AXLES. THE INNER WHEEL BEARING CONE FOR THE STEERING AXLE WHEEL HUB ASSEMBLY DOES NOT PROPERLY FIT ONTO THE NAVISTAR STEERING AXLE SPINDLE ASSEMBLY. IMPROPER FIT OF THE BEARING TO THE SPINDLE INCREASES THE STRESS LEVELS TO THE STEERING AXLE SPINDLE WHICH COULD CAUSE SPINDLE FAILURE.

Consequence

IF THE SPINDLE FAILS, A LOSS OF DRIVER CONTROL COULD OCCUR, INCREASING THE RISK OF A VEHICLE CRASH.

Remedy

DEALERS WILL REMOVE THE LEFT AND RIGHT HUB/DRUM ASSEMBLIES FROM THE STEERING AXLES AND REPLACE THE INNER WHEEL BEARING CONES AND CUPS.

Defect

VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS EQUIPPED WITH A T444E DIESEL ENGINE. THE HIGH PRESSURE OILLINE FOR THE FUEL INJECTION SYSTEM THAT GOES FROM THE HIGH PRESSURE OIL PUMP TO THE RIGHT CYLINDER HEAD CAN CHAFE AGAINST THE CHARGE AIR COOLER CROSSOVER PIPE.

Consequence

IF THIS CONDITION OCCURS, THE HOSE WILL FAIL, RESULTING IN A SUDDEN LOSS OF OIL, CAUSING THE ENGINE TO HAVE A SUDDEN LOSS OF POWER.

Remedy

DEALERS WILL INSPECT THE HOSES AND IF THE HOSE IS NOT DAMAGED A CONVOLUTED HOSE WILL BE PLACED OVER THE CURRENT HOSE. IF THE HOSE IS DAMAGED, IT WILL BE REPLACED ALONG WITH THE CONVOLUTED HOSE.

Defect

VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS EQUIPPED WITH A 1710 DRIVE LINE AND A 12 X 4 HYDRAULIC PARKING BRAKE. IF THE BRAKE DRUM OR TRANSMISSION YOKE ARE NOT FULLY SEATED WHEN THE EIGHT BOLTS ARE INSTALLED CONNECTING THE 3-PIECE JOINT, THE BOLTS CAN LOOSEN.

Consequence

BOLTS WILL EVENTUALLY WORK OUT OR SHEAR RESULTING IN DRUM AND DRIVE SHAFT SEPARATION.

Remedy

DEALERS WILL INSPECT THE TORQUE OF THESE BOLTS AND RE-TORQUE TO SPECIFICATION.