1977 Mack WS: recalls and complaints

NHTSA lists 8 recall campaigns for the 1977 Mack WS. The newest campaign is 79V137000. NHTSA received the report on 1 Jun 1979. The NHTSA record gives the component Steering / Linkages. NHTSA has no complaint on file for this model year.

The NHTSA recall file shows no do-not-drive advisory and no park-outside advisory on these campaigns.

This page cannot show if a recall applies to one vehicle. The NHTSA VIN lookup shows the unrepaired recalls of one vehicle.

Remedy of the newest campaign, 79V137000, in the NHTSA record

Dealer will inspect and retorque pitman arm, if necessary, at no cost to owner.

NHTSA VIN lookup

Complaint information entered into NHTSA’s Office of Defects Investigation vehicle owner's complaint database is used with other data sources to identify safety issues that warrant investigation and to determine if a safety-related defect trend exists.
NHTSA publishes these words. Source: NHTSA Datasets and APIs, section Complaints, read on 1 Oct 2026. Complaint file through 15 May 2019. Recall file through 29 Sep 2026.

Since the last update

No tracked figure of this page changed in a data update. What the log tracks

All updates to the register

Recall campaigns

8 campaigns, newest first. 105,943 units in total.

79V1370001 Jun 1979Steering / Linkages
79V13300031 May 1979Engine and Engine Cooling / Engine
78V2100003 Oct 1978Service Brakes, Air / Antilock / Interconnecting Assembly(Wiring)
78V1700008 Aug 1978Engine and Engine Cooling / Engine
78V0300009 Feb 1978Service Brakes, Air / Supply / Hoses, Lines/Piping, and Fittings
77V20500021 Nov 1977Suspension / Rear / Springs / Leaf Spring Assembly / Hanger/Bracket
77V17300012 Oct 1977Engine and Engine Cooling / Cooling System / Fan
77V14900019 Sep 1977Wheels / Multi Piece

79V137000Received 1 Jun 1979. 6,673 units.
Steering / Linkages
Defect, in the NHTSA record
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, in the NHTSA record
Dealer will inspect and retorque pitman arm, if necessary, at no cost to owner.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 22 Oct 1979.
79V133000Received 31 May 1979. 23,000 units.
Engine and Engine Cooling / Engine
Defect, in the NHTSA record
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, in the NHTSA record
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.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 2 Nov 1979.
78V210000Received 3 Oct 1978. 19,370 units.
Service Brakes, Air / Antilock / Interconnecting Assembly(Wiring)
Defect, in the NHTSA record
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 brake systems".
Remedy, in the NHTSA record
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.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 7 Nov 1978.
78V170000Received 8 Aug 1978. 850 units.
Engine and Engine Cooling / Engine
Defect, in the NHTSA record
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, in the NHTSA record
Dealer will inspect and, if necessary, replace aluminum support brackets with brackets made from ductile iron for increased strength.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 4 Dec 1978.
78V030000Received 9 Feb 1978. 400 units.
Service Brakes, Air / Supply / Hoses, Lines/Piping, and Fittings
Defect, in the NHTSA record
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 system pressure can cause separation of air piping connections and air system valve failure.
Remedy, in the NHTSA record
The dealer will relocate the air system compressor governor line and pressure relief valve to eliminate moisture accumulation.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 23 Aug 1978.
77V205000Received 21 Nov 1977. 7,400 units.
Suspension / Rear / Springs / Leaf Spring Assembly / Hanger/Bracket
Defect, in the NHTSA record
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.
Remedy, in the NHTSA record
Dealer will reweld the insulator spring bracket at no cost to owner.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 14 Mar 1978.
77V173000Received 12 Oct 1977. 48,000 units.
Engine and Engine Cooling / Cooling System / Fan
Defect, in the NHTSA record
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, in the NHTSA record
Dealer will replace the original fan with a steel fixed blade fan, free of charge.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 23 Mar 1978.
77V149000Received 19 Sep 1977. 250 units.
Wheels / Multi Piece
Defect, in the NHTSA record
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, in the NHTSA record
Dealer will install steel hubs in place of aluminum hubs without charge to owner.
Report filed by MACK TRUCKS, INCORPORATED. Owner notification date in the NHTSA record: 17 Jan 1978.

The campaign number opens the NHTSA record. Each quotation is the text of the NHTSA recall file.

Recall campaign: One recall in the NHTSA recall file, with one campaign number. A campaign can name many makes, models and model years.

Units: The number of vehicles or products that a recall can include. The manufacturer or the firm reports the number to the agency.

Complaints by component

The NHTSA complaint file has no complaint for this model year.

Investigations

The NHTSA investigation file has no investigation that names this model year.

Investigation: A study of a possible safety defect by the NHTSA Office of Defects Investigation. An investigation with no closing date in the NHTSA file is open.

Other model years

The number under each year is the number of recall campaigns.

19721
19731
19747
197513
19768
19778
19785
19794
19801
19811
19831
19841

A year without a link has fewer than 2 campaigns and fewer than 25 complaints. It has no page.

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Official channels

NHTSA VIN lookupNHTSA shows the unrepaired recalls of one vehicle from its VIN or its license plate.
NHTSA: report a safety problemThe NHTSA form for a complaint about a vehicle, a tire, a child seat or equipment.
NHTSA page of the 1977 Mack WSThe recalls, the complaints and the investigations that NHTSA shows for this model year.

Cite this page

Recall Register. 1977 Mack WS: recalls and complaints. https://recallregister.com/vehicle/mack/ws/1977/. Source: NHTSA Office of Defects Investigation, recall, complaint and investigation files. Data through 29 Sep 2026.

Sources

Source: NHTSA Office of Defects Investigation
Licence: US government work, public domain
Recall file through: 29 Sep 2026
Complaint file through: 15 May 2019
First complaint in the file: 1 Jan 1995
Manufacturer in the recall file: MACK TRUCKS, INCORPORATED

The NHTSA record is the authority. A complaint count is the number of different complaint numbers for the make, the model and the model year. How the register is made. Report an error.

Questions

How many units are in the recall campaigns for the 1977 Mack WS?: 105,943 units in 8 campaigns. A campaign can name other models and model years, and its units include them.
How many recall campaigns does the Mack WS have for all model years?: NHTSA lists 23 recall campaigns for the Mack WS, model years 1972 to 1984. 8 of them name the 1977 model year.
Is an NHTSA investigation of the 1977 Mack WS open?: The NHTSA investigation file has no investigation that names this model year.