The 1984 Mack Mh has 9 NHTSA recall campaigns affecting an estimated 38,527 vehicles. Recall repairs are always free at any authorized dealer. Last updated July 6, 2026.
SEAT TETHER BELTS MAY NOT HAVE BEEN ADJUSTED DURING ASSEMBLY.
DURING AN IMPACT, DRIVER AND/OR RIDER CAN MOVE FORWARDAND POSSIBLY STRIKE THE WINDSHIELD, EVEN WHEN WEARING A SEAT BELT.
ADJUST SEAT TETHER BELT IF NECESSARY.
LEFT OR RIGHT CAB STEP MAY CRACK IN ITS WELDED AREA DUE TO FLEXING OF THE STEP DURING ENTERING AND EXITING. CONSEQUENCE OF DEFECT: AS THE CRACKS EXTEND, THE TUBULAR STEP COULD PARTIALLY COLLAPSE AND…
INSTALL A REINFORCEMENT BRACE IF NO CRACKS ARE FOUND. IN ADDITION, REPLACE STEP IF CRACKS ARE PRESENT.
THE DUAL DOUBLE CHECK VALVE MAY NOT RELEASE THE PROPER AIR VOLUME TO THE BRAKE SYSTEM, CAUSING A SLIGHT TIMING DELAY BETWEEN THE TRACTOR AND THE TRAILER BRAKE SYSTEM. CONSEQUENCES OF…
INSTALL TWO NEW SLEEVES IN THE DUAL DOUBLE CHECK VALVE WHICH WILL INCREASE AIR FLOW.
THE DRAG LINKS MAY HAVE BEEN INSTALLED INCORRECTLY ALLOWING DRAG LINK CLAMP BOLT TO AXLE BEAM INTERFERENCE. CONSEQUENCE OF DEFECT: DURING A TURNING MANEUVER, INCREASED STEERING EFFORT OR COMPLETE LOCKUP…
ASSURE THAT DRAG LINKS ARE INSTALLED TO CORRECT INTERFERENCE CONDITION.
THE FLIP OUT STEP CLEVIS ON THE BUMPER MAY FAIL AND BREAK UNDER THE WEIGHT OF THE PERSON STANDING ON THE STEP TO SERVICE THE FRONT AREA OF THE VEHICLE. CONSEQUENCE OF…
REMOVE THE STEP CLEVIS AND REPLACE WITH A NEW IMPROVED CLEVIS.
THE SPRING CENTER BOLT IS NOT THE PROPER SIZE OR LENGTH. AS A RESULT, LOCATION AND ALIGNMENT OF THE SPRING TO THE FRONT AXLE MAY NOT BE CORRECT. IF THE FRONT SPRING CLIPS LOOSEN, THE INADEQUATE CENTER BOLT MAY RESULT IN SPRING TO AXLE MISALIGNMENT, SHIFTING OF THE AXLE, AND LOSS OF STEERING CONTROL.
THE DEFECT WILL BE CORRECTED BY THE ADDITION OF A SPACER BETWEEN THE SPRING AND THE CENTER BOLT HEAD TO INCREASE THE EFFECTIVE HEAD LENGTH. A LONGER CENTER BOLT WILL ALSO BE INSTALLED FOR POSITIVE RETENTION.
THE DOOR LATCHES MAY BE DEFECTIVE BECAUSE A PAWL SPRING WAS NOT MANUFACTURED TO SPECIFICATIONS. THE PAWL SPRING DOES NOT CREATE PROPER TENSION ON THE PAWL, (A PART OF THE DOOR LATCH MECHANISM). THIS CONSTITUTES A NON-COMPLIANCE WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 206, "DOOR LATCHES AND…
THE DEALER WILL INSPECT AND REPLACE DOOR LATCHES, IF NECESSARY.
DUE TO IMPROPER AND INADEQUATE WELDING PRACTICES, THE FIFTH WHEEL ON THE INVOLVED VEHICLES IS DEFECTIVE. FRAME MOUNTED SUPPORTS MAY HAVE INCOMPLETE OR POOR QUALITY WELDS. THE WELDS COULD SUBSEQUENTLY FAIL ALLOWING SEPARATION OF THE TRACTOR FROM THE TRAILER.
THE DEALER WILL INSPECT AND REMOVE THE FIFTH WHEEL AND REWELD THE MOUNTING ANGLES AT NO CHARGE TO THE OWNER.
IMPROPER STEERING CLAMP BOLTS AND TORQUE APPLIED DURING INSTALLATION. THE BOLT COULD FAIL, ALLOWING THE STEERING YOKE TO BECOME LOOSE.
INSPECTION AND, IF NECESSARY, INSTALLATION OF PROPER STEERING SHAFT CLAMP BOLTS TIGHTENED TO SPECIFICATIONS.
Recall, complaint, and investigation records from official NHTSA datasets (FLAT_RCL, FLAT_CMPL, FLAT_INV), synced weekly. Counts reflect NHTSA records for the 1984 Mack Mh as of July 6, 2026. Complaint narratives are consumer-submitted and unverified. This page contains ads and affiliate links. Full methodology.