Verdict · NHTSA data
Limited data — recalls on file
NHTSA has just 0 complaints on file for the 1989 Mack DMM — 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
A TOLERANCE MISMATCH IN THE CRANK ASSEMBLY OF THE BOSCH WINDSHIELD WIPER MOTOR COULD CAUSE INSTANTANEOUS SEPARATION OF THE CRANK FROM THE LINKAGE ASSEMBLY IN THE LEFT HAND CONTROL ARM ASSEMBLY; THIS WOULD MAKE THE SYSTEM INOPERABLE.
Consequence
WIPER FAILURE DURING VEHICLE OPERATION COULD REDUCE DRIVER'S ABILITY TO SEE THE ROAD, AND CREATES A POTENTIAL FOR AN ACCIDENT.
Remedy
REPLACE LEFT HAND CONTROL ARM LINKAGE ASSEMBLY.
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 DMM. 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.