1973 MACK HMM Recall

Campaign:: 77V173000 on 10/11/1979
Component:: Engine and engine cooling:cooling system:fan
Affected:: 48,000
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.
Correction:: Dealer will replace the original fan with a steel fixed blade fan, free of charge.
Notes:: Vehicle 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.