Mack Wl 1977

Model Wl made in 1977 by Mack got 8 recalls. There were some recalls concerningengine and engine cooling, service brakes, air and steering.

Model 1977


CampaignManufacturerManufacturing dateType# of units affectedDate Owner notified MfgRecall Initiated byManufacturers of recalled vehicles/productsReport Recieved DateRecord Creation DateRegulation Part NumberFMVSS Number
77V173000MACK TRUCKS, INCORPORATED V (Vehicle)4800003/23/1978ODIMACK TRUCKS, INC10/12/197710/12/1979
Defect SummaryThe 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 Summary
Corrective SummaryDealer will replace the original fan with a steel fixed blade fan, free of charge.
NotesVehicle description: trucks equipped with six-cylinder engines.system: engine cooling; fan.consequences of defect: broken pieces can be propelled outside of the fanshroud and will present an immediate danger and possible injury to personsstanding nearby.note: prior to correction, vehicle should not be serviced with the hood raisedand the engine running.
79V133000MACK TRUCKS, INCORPORATEDfrom 02/01/1977 to 03/01/1979V (Vehicle)2300011/02/1979ODIMACK TRUCKS, INC05/31/197910/12/1979
Defect SummaryIn 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.
Consequence Summary
Corrective SummaryDealer 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.
NotesVehicle description: trucks equipped with endt (b) 676, etaz (b) 673a, and etay(b) 673a engines.system: engine and engine cooling.consequences of defect: engine lubricating oil, in the presence of a source ofignition, could lead to an engine compartment fire and serious injury tovehicle passengers.
78V170000MACK TRUCKS, INCORPORATED V (Vehicle)85012/04/1978MFRMACK TRUCKS, INC08/08/197810/12/1979
Defect SummaryThe 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.
Consequence Summary
Corrective SummaryDealer will inspect and, if necessary, replace aluminum support brackets with brackets made from ductile iron for increased strength.
NotesVehicle description: trucks.system: engine; engine mounting bracket.consequences of defect: loss of throttle control may result in loss of vehiclecontrol and an accident.
78V210000MACK TRUCKS, INCORPORATEDfrom 10/01/1977 to 09/01/1978V (Vehicle)1937011/07/1978MFRMACK TRUCKS, INC10/03/197810/12/1979571121
Defect SummaryDelays 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.
Consequence Summary
Corrective SummaryDealer 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.
NotesVehicle description: heavy trucks.system: service brakes; electrical wiring and connectors.consequences of defect: this delay in effective braking action could lead to anaccident under certain traffic conditions.
78V030000MACK TRUCKS, INCORPORATEDfrom 12/01/1975 to 01/01/1978V (Vehicle)40008/23/1978MFRMACK TRUCKS, INC02/09/197810/12/1979
Defect SummaryA 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.
Consequence Summary
Corrective SummaryThe dealer will relocate the air system compressor governor line and pressure relief valve to eliminate moisture accumulation.
NotesVehicle description: trucks equipped with anchorlok air dryers.system: service brakes; air system and governor control line (air dryer).consequences of defect: when this occurs, automatic application of the chassisemergency spring brakes and trailer brakes could cause loss of vehicle controlwithout prior warning and a vehicle accident.note: owner/driver is advised not to operate vehicle if air pressure exceeds15o psi.
79V137000MACK TRUCKS, INCORPORATEDfrom 05/01/1977 to 04/01/1979V (Vehicle)667310/22/1979MFRMACK TRUCKS, INC06/01/197910/12/1979
Defect SummaryThe 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.
Consequence Summary
Corrective SummaryDealer will inspect and retorque pitman arm, if necessary, at no cost to owner.
NotesVehicle description: trucks.system: steering linkages; arm, pitman.consequences of defect: this condition could lead to premature wearing of theoutput shaft causing loss of vehicle control and an accident.
77V205000MACK TRUCKS, INCORPORATEDfrom 05/01/1977 to 10/01/1977V (Vehicle)740003/14/1978MFRMACK TRUCKS, INC11/21/197710/12/1979
Defect SummaryA 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 Summary
Corrective SummaryDealer will reweld the insulator spring bracket at no cost to owner.
NotesVehicle description: heavy trucks.system: suspension; tandem axle.consequences of defect: this condition could cause a loss of vehicle controland a vehicle accident.
77V149000MACK TRUCKS, INCORPORATED V (Vehicle)25001/17/1978MFRMACK TRUCKS, INC09/19/197710/12/1979
Defect SummaryThe 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.
Consequence Summary
Corrective SummaryDealer will install steel hubs in place of aluminum hubs without charge to owner.
NotesVehicle description: trucks equipped with ff-931 front axles.system: wheels; aluminum hubs, front.consequences of defect: hub failure could result in loss of vehicle control andan accident.note: hub failure may be indicated by an audible sound at the instant of hubseparation, along with thumping or wheel wobble. hub may separate from thewheel and still be retained on the axle.