Technical Does no-play mean zero?

After waiting over a month for parts, my kingpin set finally arrived for the Apache I slid the new one in, and noticed it had the tiniest wiggle. Everything I've read says there should be no play, so I decided to measure what I have. The DI tells me .001 right at the axle. I stuck a .0015 feeler gauge on the kingpin and it still went in by hand, but seemed snug.
I really don't want to redo the axle for just a thou of play. I was thinking of getting some shim stock at Grainger and sliding in a sliver, maybe? I've seen the suggestion of torch shrink/ream, but where would I find the correct reamer? Thanks all, as always, for your help!

 

I would be happy with that fit. I honestly don't know how you can get any better

 

An adjustable reamer would work, but getting a fit better than a thou would be challenging.

I'd leave it....

 

Is it loose in the axle or the spindles

 

I thought he was talking about the pin fit in the axle....not in the bushings.

 

In the axle. I don't think I need any grease in the axle, since the kingpin shouldn't spin in the axle (if it does spin, that's a whole new can of worms, haha).
Thanks all for the help, guys! I just wanted to make I wasn't looking for a vacuum tight slip fit

 

X2 squirrel

 

No-play means nil.

 

What keeps the kingpin from turning in the axle?
On Fords the tapered lock pin prevents turning and locks the pin to the axle.

 

There is a flat on the kingpin, and a crossbolt with a matching flat that goes through axle perpendicularly. Kind of a funky deal, I wish they'd made the bolt tapered so that it could also help take up some slop when you tightened it, maybe.

 

Ahh, increasing our vocabulary are we?

 

I always thought it would have been a good idea to have a lock bolt near the top of the axle and one near the bottom. This would help stop the slop from ever happening. It would also be more expensive to produce and be of little benefit to the the person that owned the vehicle for the first 15 years of its life.

It's no wonder no engineer thought doing it my way would pay off.

 

You will always have some play in the axle, its not meant to be tight. Thats the job of the wedge that you either drive in or tap in and tighten done.

One of these days I need to do a video on proper king pin reaming and fitting. Its scary how many bad jobs I see in the shop each year.

 

Alot of semi's do.....

 

Can you assemble it, then use the torch to heat the axle boss and shrink it?

 

I have done a few king pins in old cars and pu trucks and dozens in big trucks... The king pin should be hand press sliding fit in the axle for the reverse Elliot axles...In the real world in a light vehicle a thousands or two might be ok...
Guys here mentioning hammering on axles...In the end the upper and lower bearing surfaces must be a true 90 degrees to the pin..

 

I'm not talking about a hammer, I'm talking heat and cool cycles.

 

There were guys talking about hammering......So the heat and cool shrinks the pin bore?

 

That's what I'm asking, if you heat the boss and cool it quick, won't it shrink the bore? So if you put the thing together and heat just the axle boss, then hit it with the blow valve? Yes? No? Swear I'm not drinking this evening lol

 

I have no idea if it'll work....

 

No

 

The concept of heating the boss on an axle to remove a stuck pin sort of makes sense to me, but heating the axle boss to tighten the clearance on a new pin in the bore just doesn't work at all for me. How would you determine how much heat was needed, and how do you keep the length of the bore consistent?

On the original post, is the bore too large, or is the pin undersized? Did you try a different pin? Doesn't take much either way to add a 1/2 a thousandth clearance. I'd probably just go with it as is.

 

When I first started working in a machine shop, 50-odd years ago, an old, well respected German master machinist explained it by saying, "Loose, mitt no shake". Never forgot it.

 

Again I don't understand the problem. Put it together and let the wedge pin do its job.... Just that simple.

The point of the clearance is to allow you to take it apart again instead of it being a solid rusted together piece of iron.

2-1/2 ton and bigger trucks will on occasion rust themselves solid, out comes the heating torch and big hammer. Have been thru some of those that took large amounts of time and energy to take apart.

Again, its just fine.....

 

The new kingpins I got are the same diameter as the ones I pulled out (after scotchbriting the rust and gunk off), so I think the axle and kingpins are original size.
I played around some more with the feeler gauges. .003, total no go. .002 will go in with some effort, and it takes some grunt to get the pin and gauge back out. Pretty sure the locking bolt with take that up, so think I'll run it as.
Regarding the heat shrinking without hammering, I see where you are coming from. Saw a hotrod show where they were heat shrinking dents without a hammer, so they didn't mar the metal. My only thought on it would be that the metal on the axle side would cool more slowly than the unsupported metal on the outside, so you would end up with an oblong hole from the different cooling rates, so you would still need to ream.
Thanks again, everyone, for the thoughtful help and comments!

 

Does any piece of metal change size just because it was heated and then cooled?

I hope not, because all my measuring tools get heated and cooled every day, just sitting in my tool box.

When working with sheet metal...you don't heat it all uniformly, it's not the same as the end of an axle.

 

You would have to get to stress relieving temperature then you coukd release the internal stresses from cold the cold rolled ground and polish, but that would be north of 800 degrees.

BTW I I bought NOS aftermarket king pins/bushings for the Chieftain and did not have to ream. Slight press to install bushings and pins went right in. But they didnt feel “Loose”. I would think any measurement of the gap with feeler gages woul be on the low side relative to using a bore gage and OD mics.

 

Ya, I wouldn't know. I try not to work on anything big enough to hurt me if it falls on me.

 

A thin layer of grease would prevent corrosion...therefore a good idea? I mean I think of the Perch pin stories...another place that could use some lube...