Verdict · NHTSA data
Limited data — recalls on file
NHTSA has just 0 complaints on file for the 1999 Navistar 9100 — too few to judge reliability from owner reports alone — but 4 recall campaigns apply to this year, so any used example should have its VIN checked for completed recall work.
0
NHTSA complaints
4
Recalls
0
Investigations
0
Crash-involved
0
Fires reported
0
Injuries
0
Deaths
—
NCAP overall
4 NHTSA recall campaigns on file. Recall repairs are free at franchised dealers.
Defect
VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS. THE ANTILOCK TRACTION RELAY VALVES WERE INCORRECTLY ASSEMBLED BY THE SUPPLIER. AN EXTRA CHECK VALVE WAS INSTALLED WHICH WILL NOT ALLOW THE TRACTION CONTROL SYSTEM TO FUNCTION PROPERLY.
Consequence
THE REAR BRAKES CAN BE APPLIED AUTOMATICALLY DURING A TRACTION EVENT AND NOT RELEASE UNTIL THE AIR SYSTEM PRESSURE IS DEPLETED.
Remedy
DEALERS WILL INSPECT THESE VEHICLES AND ALL ANTILOCK TRACTION RELAY VALVES FOUND DEFECTIVE WILL BE REPLACED.
Defect
VEHICLE DESCRIPTION: HEAVY DUTY TRUCKS EQUIPPED WITH DANA/SPRAGUE WINDSHIELD WIPER ASSEMBLIES. THE KNURLED PIVOT SHAFT (WHICH OPERATES THE WINDSHIELD WIPER ARM) IS WELDED TO A LEVER, WHICH CONNECTS TO LINKAGE FROM THE WIPER MOTOR. THE WELD AT THE PIVOT SHAFT TO LEVER CAN FAIL.
Consequence
SHOULD A FAILURE OCCUR DURING INCLEMENT WEATHER ON THE DRIVER'S SIDE WHILE THE VEHICLE IS IN MOTION, THE OPERATOR'S VISION WOULD BE PARTIALLY OBSCURED.
Remedy
DEALERS WILL INSPECT THE WIPER SYSTEM, CONDUCTING A "STALL" TEST TO VALIDATE THE INTEGRITY OF THE WELD. ALL WIPER ASSEMBLIES FAILING THIS TEST WILL BE REPLACED.
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: HEAVY DUTY TRUCKS EQUIPPED WITH SPICER SPL170 55MM CENTER BERING PACKAGE. THE END YOKE RETAINING NUT CAN LOOSEN.
Consequence
IF THIS CONDITION OCCURS, THE DRIVE LINE CAN VIBRATE AND SEPARATE FROM THE VEHICLE, CAUSING VEHICULAR DAMAGE, OR PERSONAL INJURY, OR BOTH.
Remedy
DEALERS WILL REMOVE THE 55MM CENTER BEARING PACKAGE AND COUPLER SHAFT, AND REPLACE IT WITH A NEW COUPLER SHAFT AND A 60MM CENTER BEARING PACKAGE. AN INTERIM REMEDY CAN BE IMPLEMENTED BY PLACING A SPOT WELD ON THE COUPLING SHAFT THREADS UNTIL PARTS ARE AVAILABLE.
The record is thin — 0 NHTSA complaints — so owner-report data can't strongly confirm reliability either way, though 4 recalls should be verified as completed.
Yes — NHTSA lists 4 recall campaigns affecting the 1999 Navistar 9100. Recall repairs are free at franchised dealers; check the VIN at nhtsa.gov/recalls to confirm the work was done.
Based on NHTSA ODI data through June 2026. Complaints are consumer-reported and unverified. Updated July 5, 2026.
Compiled by Sharon Ben-Moshe, Founder.