Mack WS Problems by year

Improper steering clamp bolts and torque applied during installation. The bolt could fail, allowing the steering yoke to become loose.

The spring seat plate, located between the axle housing and the suspension springs, may deform due to spring bending. As a result, the clamping force in the assembly may be reduced. Loss of clamping force could cause spring failure and the axle will...

The flange head pinch bolts used in the yokes of the steering shaft assemblies may have been overstressed due to the bolts not being tightened to specifications. As a result, the pinch bolts could break while in service.

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.

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...

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...

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...

An axle "no brake" condition could result from an eaton controller internal electrical malfunction. This condition may cause the anti-wheel lock valve solenoid to be continuously energized and prevent the brakes from being applied on one of the axles. As a...

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...

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...

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 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.