Verdict · NHTSA data
Limited data — recalls on file
NHTSA has just 0 complaints on file for the 1989 Mack MH — too few to judge reliability from owner reports alone — but 2 recall campaigns apply to this year, so any used example should have its VIN checked for completed recall work.
0
NHTSA complaints
2
Recalls
0
Investigations
0
Crash-involved
0
Fires reported
0
Injuries
0
Deaths
—
NCAP overall
2 NHTSA recall campaigns on file. Recall repairs are free at franchised dealers.
Defect
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.
Consequence
IN THE EVENT THE PRIMARY THROTTLE RETURN FAILS, FAILURE OF THE SECONDARY THROTTLE RETURN SYSTEM WOULD NOT PROVIDE PROTECTION AGAINST LOSS OF THROTTLE CONTROL.
Remedy
A NEW PRODUCTION SECONDARY THROTTLE RETURN SYSTEM CONFIGURATION WILL BE INSTALLED.
Defect
TORQUE ROD BOLTS ARE GRADE 2 INSTEAD OF GRADE 5, WHICH IS NOT TO SPECIFICATION, AND COULD FAIL.
Consequence
BOLT FAILURE COULD ALLOW THE REAR AXLE TO SHIFT; THISCOULD ADVERSELY AFFECT TRUCK CONTROL AND COULD RESULT IN A CRASH.
Remedy
REPLACE TORQUE ROD BOLTS WITH BOLTS OF THE PROPER SPECIFICATION.
The record is thin — 0 NHTSA complaints — so owner-report data can't strongly confirm reliability either way, though 2 recalls should be verified as completed.
Yes — NHTSA lists 2 recall campaigns affecting the 1989 Mack MH. 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.