1979 Mack DMM problems

Verdict · NHTSA data

Limited data — recalls on file

NHTSA has just 0 complaints on file for the 1979 Mack DMM — too few to judge reliability from owner reports alone — but one recall campaign applies to this year, so any used example should have its VIN checked for completed recall work.

NHTSA complaints

Recalls

Investigations

Crash-involved

Fires reported

Injuries

Deaths

—

NCAP overall

Does the 1979 Mack DMM have recalls?

1 NHTSA recall campaign on file. Recall repairs are free at franchised dealers.

79V133000EngineMay 31, 1979 · 23,000 units

Defect

IN THE EVENT OF TURBOCHARGER COMPRESSOR WHEEL FAILURE, ONE OR MORE OF THE FOUR CAPSCREWS THAT HOLD THE TURBOCHARGER TOGETHER MAY BE STRUCK BY PARTS OF THE COMPRESSOR WHEEL, RESULTING IN THE CAPSCREWS BEING DAMAGED. IF THESE CAPSCREWS ARE DAMAGED TO THE POINT THAT THEY ALLOW THE COMPRESSOR BACK PLATE TO DISLOCATE FROM THE TURBOCHARGER BEARING HOUSING, ENGINE LUBRICATING OIL MAY BE ALLOWED TO ESCAPE UNDER PRESSURE, CONTACTING THE ENGINE EXHAUST MANIFOLD SECTIONS OR TURBOCHARGER TURBINE HOUSING.

Remedy

DEALER WILL INSTALL A SHIELD FOR THE HEADS OF THE FOUR CAPSCREWS, ALONG WITH STRONGER SAE 8 GRADE 8 CAPSCREWS, IF NECESSARY, AT NO COST TO OWNER.

1979 Mack DMM — common questions

Is the 1979 Mack DMM reliable?

The record is thin — 0 NHTSA complaints — so owner-report data can't strongly confirm reliability either way, though 1 recall should be verified as completed.

Does the 1979 Mack DMM have recalls?

Yes — NHTSA lists 1 recall campaign affecting the 1979 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.

Does the 1979 Mack DMM have recalls?

1979 Mack DMM — common questions

Is the 1979 Mack DMM reliable?

Does the 1979 Mack DMM have recalls?

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