1999 Navistar 4900

VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS. THERE IS INTERFERENCE BETWEEN THE AIR BRAKE S-CAM AND THE END OF ONE OF THE KNUCKLE STUDS. AS THE BRAKE SHOE LINING WEARS, THE S-CAM ROTATION MAY BE LIMITED BY THE INTERFERING KNUCKLE STUD. IF THE S-CAM CAN NOT ROTATE THROUGH ITS FULL RANGE OF MOTION, THE BRAKING FORCE CAN NOT BE FULLY TRANSMITTED FROM THE BRAKE SHOE LININGS TO THE BRAKE DRUMS.

RiskTHIS COULD RESULT IN A LONGER STOPPING DISTANCE OR A DRAGGING BRAKE CONDITION.

FixDEALERS WILL SHORTEN THE INTERFERING KNUCKLE STUD TO ELIMINATE THE CLEARANCE PROBLEM.

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.

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

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

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.

RiskWITHOUT SUFFICIENT TORQUE ON THE GUIDE PAWL CAP SCREW, THE BRAKES COULD GRADUALLY LOSE ADJUSTMENT, INCREASING THE VEHICLE STOPPING DISTANCE.

FixDEALERS 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.

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.

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

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

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.

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

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