The 1989 Mack Mh has 2 NHTSA recall campaigns affecting an estimated 39,877 vehicles. Recall repairs are always free at any authorized dealer. Last updated July 5, 2026.
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.
IN THE EVENT THE PRIMARY THROTTLE RETURN FAILS, FAILURE OF THE SECONDARY THROTTLE RETURN SYSTEM WOULD NOT PROVIDE PROTECTION AGAINST LOSS OF THROTTLE CONTROL.
A NEW PRODUCTION SECONDARY THROTTLE RETURN SYSTEM CONFIGURATION WILL BE INSTALLED.
TORQUE ROD BOLTS ARE GRADE 2 INSTEAD OF GRADE 5, WHICH IS NOT TO SPECIFICATION, AND COULD FAIL.
BOLT FAILURE COULD ALLOW THE REAR AXLE TO SHIFT; THISCOULD ADVERSELY AFFECT TRUCK CONTROL AND COULD RESULT IN A CRASH.
REPLACE TORQUE ROD BOLTS WITH BOLTS OF THE PROPER SPECIFICATION.
Recall, complaint, and investigation records from official NHTSA datasets (FLAT_RCL, FLAT_CMPL, FLAT_INV), synced weekly. Counts reflect NHTSA records for the 1989 Mack Mh as of July 5, 2026. Complaint narratives are consumer-submitted and unverified. This page contains ads and affiliate links. Full methodology.