kingpin bump
 

Is there a purpose for the bump on the top of the kingpin?

Re: kingpin bump
 

I think it allowed the body of the kingpin to be machined between centers in a lathe? The dimple/recess in the bump is frequently filled with paint.

Joe K

Re: kingpin bump
 

Joe has it, the dimple at the top was for machining the shaft central. It would be placed between a live centre on the tail stock and a dead centre in the spindle and be driven by a dog. This would ensure the core for the brake pin was in the centre of the kingpin after the shaft was machined, and makes it quick and easy to accurately install in the lathe.

Re: kingpin bump
 

Sure, that makes sense. I hadn't thought about the manufacturing process.... just the end part.

Thanks.