1977 Mack Ws Recalls, Complaints & Specs
8 safety recalls list the 1977 Mack Ws. Check your own VIN below.
8 safety recalls for the 1977 Mack Ws
Most recent first. Recall repairs are free at any authorised dealer. Click a recall for the full defect, consequence and remedy text.
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Linkages (steering)
The pitman arm retaining nut may not have been torqued to manufacturer specifications. This could result in inadequate retention of the nut at the output shaft, allowing the pitman arm to become loose.
Remedy: Dealer will inspect and retorque pitman arm, if necessary, at no cost to owner.
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Engine (engine and engine cooling)
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…
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.
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Interconnecting assembly(wiring) (service brakes)
Delays of up to about 2 seconds may exist in the brake application times to the brakes on the bogie axles in the presence of certain types of wheel speed sensor signal discontinuities or distortions that may occur as a result of sensor wire failure. This constitutes a non-compliance to federal motor vehicle safety standard no. 121, "air…
Remedy: Dealer will install new wheel speed sensors that incorporate improved wiring and the present bogie anti-wheel lock system will be changed to an axle-to-axle system for improved reliability.
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Engine (engine and engine cooling)
The possibility exists that the aluminum engine rear support brackets may fail due to metal fatigue. This type of failure would allow the engine and transmission assembly to dislocate downward. This will result in throttle control loss with the engine operating continuously in the mid to upper range of the governed speed range.
Remedy: Dealer will inspect and, if necessary, replace aluminum support brackets with brackets made from ductile iron for increased strength.
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Hoses, lines/piping, and fittings (service brakes)
A design deficiency exists in the air dryer piping in the area of the pressure relief valve and compressor governor control link. Moisture is passed and builds up in this relief valve and control line. In freezing ambient temperatures, this moisture may freeze, allowing the chassis air system pressure to exceed 150 PSI. Excessive air…
Remedy: The dealer will relocate the air system compressor governor line and pressure relief valve to eliminate moisture accumulation.
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Hanger/bracket (suspension)
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…
Remedy: Dealer will reweld the insulator spring bracket at no cost to owner.
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Fan (engine and engine cooling)
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.
Remedy: Dealer will replace the original fan with a steel fixed blade fan, free of charge.
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Multi piece (wheels)
The front wheel aluminum hubs on the involved vehicles may be subject to cracks which may progress circumferentially around the barrel of the hub. This could lead to a fracture in the "barrel" position of the hub and complete hub failure.
Remedy: Dealer will install steel hubs in place of aluminum hubs without charge to owner.
No owner complaints on file
NHTSA has no owner complaints on file for the 1977 Mack Ws. For context, the average model year in NHTSA's database has dozens; a zero can mean a reliable vehicle, a rare one, or both.
Compare Mack Ws model years
Recall and complaint counts for every Mack Ws model year in NHTSA's database.
| Model year | Recalls | Complaints |
|---|---|---|
| 1972 Mack Ws | 1 | 0 |
| 1973 Mack Ws | 1 | 0 |
| 1974 Mack Ws | 7 | 0 |
| 1975 Mack Ws | 13 | 0 |
| 1976 Mack Ws | 8 | 0 |
| 1977 Mack Ws | 8 | 0 |
| 1978 Mack Ws | 5 | 0 |
| 1979 Mack Ws | 4 | 0 |
| 1980 Mack Ws | 1 | 0 |
| 1981 Mack Ws | 1 | 0 |
| 1983 Mack Ws | 1 | 0 |
| 1984 Mack Ws | 1 | 0 |
Checking a specific 1977 Mack Ws
How do I know if my 1977 Mack Ws has an open recall?
Enter your 17-character VIN above. The VIN is on the driver's side dashboard (visible through the windshield), the driver's door jamb sticker, and your registration or insurance card. The check runs against NHTSA's live database and tells you which campaigns list your vehicle. 8 campaigns currently list the 1977 Mack Ws; your car may already have been repaired under some of them.
Is the recall repair free?
Yes. Under federal law, manufacturers must fix safety recalls at no charge for vehicles up to 15 years old from the date of sale to the first owner. Contact any authorised Mack dealer with your VIN and the NHTSA campaign number (for example 77V149000).
What is the difference between a recall and a complaint?
A recall is a safety campaign filed by the manufacturer or ordered by NHTSA, with a defined defect and remedy. A complaint is a report an owner sent to NHTSA; it is not verified, but patterns of complaints are what trigger NHTSA investigations and, eventually, recalls.
Other Mack models
- Mack28 complaints
- Anthem (an)12 complaints
- Granite (gr)9 complaints
- CXU6127 complaints
- Ch6 complaints
- Gu6 complaints
- CH6005 complaints
- Cxu5 complaints
Source: NHTSA recall and complaint databases and EPA fuel economy data, October 2026. Complaint counts are owner reports to NHTSA, not verified defects. Recall counts are safety campaigns that list this model year; whether a particular car was already repaired depends on its VIN. How this data is compiled.