When Do You Know It's Time To Replace Kingpins?

[engine2quarters]

I have a 1945 Mack, type EF/EG with an EN-330 6 cylinder engine.

A local truck 'mechanic' was doing a pre-state inpection 'look thru' on my truck, for me. He checked the play in the steering, then moved over to the individual wheels. Raised the front axle on one side, pried the wheel up and down, then in and out and found no excessive play. He then raised the jack some more, put the breaker bar under the wheel, and pushed the wheel up, and it moved upwards. He said that I need new kingpins, pointing to it, sliding up and down.

I thought sloppy wheel play or badly worn (uneven) tires indicated the need for king pin replacement? Anything else?

Keep in mind, this 'mechanic' couldn't find my emergency brake (located on the driveshaft) nor my power steering assembly (which it hasn't). The truck does not have shock absorbers of any type.

I don't want to replace them Yking pins) if they don't need to be replaced. IF I can find replacements, that is.

[Rob]

I have a 1945 Mack, type EF/EG with an EN-330 6 cylinder engine.

A local truck 'mechanic' was doing a pre-state inpection 'look thru' on my truck, for me. He checked the play in the steering, then moved over to the individual wheels. Raised the front axle on one side, pried the wheel up and down, then in and out and found no excessive play. He then raised the jack some more, put the breaker bar under the wheel, and pushed the wheel up, and it moved upwards. He said that I need new kingpins, pointing to it, sliding up and down.

I thought sloppy wheel play or badly worn (uneven) tires indicated the need for king pin replacement? Anything else?

Keep in mind, this 'mechanic' couldn't find my emergency brake (located on the driveshaft) nor my power steering assembly (which it hasn't). The truck does not have shock absorbers of any type.

I don't want to replace them Yking pins) if they don't need to be replaced. IF I can find replacements, that is.

It sounds like the flat pack thrust bearings that the king pin mouts through is shot, or needs shimmed. There should only be about .015 clearance, (maximum) from the top of the bearing, to the spindle itself. This bearing is mounted between the lower part of the axle beam, and above the lower part of the steering knuckle, (spindle). These bearing also carry the actual weight of the front end upon them. If the actual king pin and bushings were shot, there would be axial play, (in and out of the top of the tire) and the front end would tend to shake violently with pothole impact.

I believe the steering axle you have uses straight pins, and not tapered.

Rob