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1977 Mack Hmm

Owner reports · Recalls · Investigations

Limited comparison data

There is not enough comparable history to draw a useful model-year comparison.

About this comparison →
0Owner complaints

Model-year median: 0

4Recall campaigns

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0Investigations

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How this year compares

Owner complaints by model year

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19740
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1977
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Counts vary with age, sales and reporting. They are not failure rates.

What owners reported most

No component reports in this snapshot.

Tap a category to read its complaints. One report may name several components.

When problems were reported

Mileage at the reported incident

Limited mileage data: 0 of 0 reports include usable mileage. There isn’t enough coverage to show a useful chart.

NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.

NHTSA owner reports · September 18, 2026 snapshot.

0 crash reports0 fire reports0 injury reports

What owners actually said

0 reports

No matching complaints in this snapshot.

Official recalls

4

77V204000 · Seat Belts:front:anchorage

Nov 21, 1977

THE INVOLVED VEHICLES DO NOT CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NOS. 207, "SEATING SYSTEMS", AND 210, "SEAT BELT ASSEMBLY ANCHORAGES". VEHICLES EQUIPPED WITH VIKING T-BAR SEATS HAVE THE SEAT BELT ANCHORAGE LOCATED UNDER THE SEAT. THE TETHER BELT RUPTURED WHEN SUBJECTED TO THE FORCES REQUIRED IN THE SAFETY TEST.

Consequence & remedy

Consequence: Not supplied

Remedy: DEALER WILL RELOCATE THE TETHER BELT FLOOR ANCHORAGE TO CORRECT THE PROBLEM, WITHOUT CHARGE TO OWNER.

77V205000 · Suspension:rear:springs:leaf Spring Assembly:hanger/bracket

Nov 21, 1977

A DEFICIENCY EXISTS IN THE WELDS SECURING THE REAR SPRING INSULATOR BRACKET TO THE AXLE HOUSING. THIS IS DUE TO IMPROPER POSITIONING OF THE WELD, IN RELATIONSHIP TO THE BRACKET AND AXLE HOUSING. FAILURE OF THE WELDS WOULD CAUSE SEPARATION OF THE SPRING INSULATOR BRACKET AND THE AXLE HOUSING, RESULTING IN IMPROPER ALIGNMENT OF THE AFFECTED AXLE.

Consequence & remedy

Consequence: Not supplied

Remedy: DEALER WILL REWELD THE INSULATOR SPRING BRACKET AT NO COST TO OWNER.

77V173000 · Engine And Engine Cooling:cooling System:fan

Oct 12, 1977

THE FLEX BLADE FANS ON THE INVOLVED VEHICLES MAY DEVELOP CRACKS IN THE LAMINATED STIFFENER AS A RESULT OF FATIGUE DURING OPERATION. IF SUCH A CONDITION EXISTS AND THE CRACKS GO UNDETECTED, CONTINUED OPERATION COULD CAUSE PIECES OF THE STIFFENER TO BREAK OFF.

Consequence & remedy

Consequence: Not supplied

Remedy: DEALER WILL REPLACE THE ORIGINAL FAN WITH A STEEL FIXED BLADE FAN, FREE OF CHARGE.

77V174000 · Seat Belts:front:anchorage

Oct 12, 1977

THE INVOLVED VEHICLES DO NOT CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 209, "SEATBELT ASSEMBLIES". ALTHOUGH THE SEATBELTS IN QUESTION PERFORMED MARGINALLY WITH RESPECT TO THE 5000 LB. LOAD REQUIREMENT, ADDITIONAL TESTING CONFIRMED THAT THE ANCHOR COULD FAIL, ALLOWING EITHER THE ANCHOR TO SLIP OVER THE HOLD-DOWN NUT OR THE ANCHOR TO SEPARATE INTO TWO PIECES.

Consequence & remedy

Consequence: Not supplied

Remedy: DEALER WILL INSPECT AND, IF NECESSARY, REPLACE SEAT BELT ASSEMBLIES WITHOUT CHARGE TO OWNER.

Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗

NHTSA investigations

0

No exact-year investigations in this snapshot.