What part wears out on king pins? Do I need to replace the whole pin itself? Or just the bushings? Pass side has no play the driver side have a very tiny bit of play.

 

If it looks something like this, it's time for a new one.



(This one came off a 64 I had back in the 1980's--failed while I was hauling a trailer from California to Montana.

~Steve

 

Assuming you are talking about a straight axle. It's usually just the bushings that wear under normal wear. Most kits come with both bushings and pins plus the bearings and shims. The bushings need to be pressed out and in, then reamed to fit the pin, best to find a shop that can do that.

 

so it's not as easy as out with the old in with the new? The bushings don't already come sized to fit?

 

Correct, the bushings need to be reamed and that takes a special reamer..

 

Darn it. What is required in the reaming process? A reamer and a lathe correct?

 

How much play does there need to be to justify rebuilding the king pin?

 

Not much. Thing to remember with bearings, esp. critical safety items like steering components is they take a long time to show any appreciable wear or play at all. What you'll find though is once wear starts to become evident it accelerates very rapidly.
It's not a linear thing and why the go/no go criteria is so small, maybe .005" - 007" or whatever it is. It will be 1/4" before ya know it. Yikes!

If they are showing some wear take care of it now. Stands to reason, they are totally shot by now anyway unless there is good reason to believe otherwise.

 

Just the reamer. They are made so the reaming is parallel from the top to the bottom the best I can describe it. Finding a shop that still has one can be a little challenging. I have seen them on Ebay but not very often..

 

King pin kit same: 1957/64 F100.

 

just a fyi. if you do come up with a reamer, go SLOW. the difference between just a little too tight and too loose is tiny. baby steps!

 

I pressed my bushings in, but had them reamed at a place locally that works on large trucks. A local machine shop couldn't do it!

 

I pressed my own bushings, but a friend with a mill sized them for me.

 

Ok. My roommate from college is a machinist, I'll see if he has the capabilities