RoadVitals

1977 Mack Hmm Recalls

Safety recall campaigns filed with NHTSA that cover this model year

Recalls apply to specific vehicles, not to every vehicle of a model year. Check your VIN with NHTSA or your manufacturer's dealer to confirm whether a recall affects your vehicle.

Check a VIN on NHTSA.gov
Recall campaignsA safety recall is issued when a manufacturer or NHTSA determines that a vehicle has a safety-related defect or does not comply with a federal motor vehicle safety standard. Recall repairs are free. Whether a specific vehicle is covered depends on its VIN — a recall listed for a model year does not necessarily apply to every vehicle of that year.
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Newest Nov 21, 1977
Carrying an NHTSA advisoryCampaigns where NHTSA told owners not to drive the vehicle, or to park it outside, until the repair is done.
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Open investigationsNHTSA opens an investigation to examine whether a safety defect may exist. An open investigation is not a determination that a defect exists, and many investigations close without a recall. Investigations can, however, lead to one.
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Recall campaigns

4 campaigns cover this model year — what the defect is, what it could cause, and what the remedy is

77V205000

SUSPENSION:REAR:SPRINGS:LEAF SPRING ASSEMBLY:HANGER/BRACKET

Nov 21, 1977
7,400 units potentially affected
The defect: 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.
The remedy: DEALER WILL REWELD THE INSULATOR SPRING BRACKET AT NO COST TO OWNER.
MACK TRUCKS, INCORPORATEDView on NHTSA.gov
77V204000

SEAT BELTS:FRONT:ANCHORAGE

Nov 21, 1977
11 units potentially affected
The defect: 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.
The remedy: DEALER WILL RELOCATE THE TETHER BELT FLOOR ANCHORAGE TO CORRECT THE PROBLEM, WITHOUT CHARGE TO OWNER.
MACK TRUCKS, INCORPORATEDView on NHTSA.gov
77V174000

SEAT BELTS:FRONT:ANCHORAGE

Oct 12, 1977
6,591 units potentially affected
The defect: 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.
The remedy: DEALER WILL INSPECT AND, IF NECESSARY, REPLACE SEAT BELT ASSEMBLIES WITHOUT CHARGE TO OWNER.
MACK TRUCKS, INCORPORATEDView on NHTSA.gov
77V173000

ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN

Oct 12, 1977
48,000 units potentially affected
The defect: 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.
The remedy: DEALER WILL REPLACE THE ORIGINAL FAN WITH A STEEL FIXED BLADE FAN, FREE OF CHARGE.
MACK TRUCKS, INCORPORATEDView on NHTSA.gov

What a recall is

Safety recall
A safety recall is issued when a manufacturer or NHTSA determines that a vehicle has a safety-related defect or does not comply with a federal motor vehicle safety standard. Recall repairs are free. Whether a specific vehicle is covered depends on its VIN — a recall listed for a model year does not necessarily apply to every vehicle of that year.
Safety investigation
NHTSA opens an investigation to examine whether a safety defect may exist. An open investigation is not a determination that a defect exists, and many investigations close without a recall. Investigations can, however, lead to one.
Manufacturer communication
Manufacturers file copies of the bulletins they send to dealers with NHTSA. These often describe diagnostic or repair procedures for a known condition. They are not recalls: repairs described in a bulletin are usually only free if the vehicle is still under warranty or the manufacturer has extended coverage.

Elsewhere on this vehicle

Data sources