The Stovebolt Site Forums The Shop Area Driveline King Pin Help

I will be needing to do the king pins on my 1953 GMC 100, by recommendation of my mechanic. Do I measure the bore or the king pin to determine the size I should order (I realize they should be pretty close, but this is my first time doing this and I don't have any history on the truck).

DId your mechanic say the king pins are loose in the axle and/or in the bushings in the steering knuckles?

He didn't say. He said to check them because they were loose (I asked him to look over the front end for me to make sure everything was safe down there).

Measure either if they fit good and snug. Should be able to push the pin in the axle by hand or light taps with a mallet but will not fall out.
If sloppy in the axle measure the bore to see if metal is available to ream for an oversized kingpin to solve the problem.
If really sloppy enough that oversize kingpin can't be fit you replace the axle.

Pretty sure there is just standard size and one oversize which is likely 0.010" over. Have you checked to see what is available?

Rockauto.com only shows standard and 0.010" over.

Thank you both ^^ It is because I saw what was available that I'm wondering where to measure to make sure to order the correct size.

A lot of people order the 0.010" oversize as a knee jerk response before inspecting the pin-to-axle fit. Most times the only worn part is the bushings. The kingpins will usually look like new. Too bad you can't buy just the bushings (without the kingpins).
Carl

Carl is correct about checking for looseness in the pin-to-axle fit.

However, my experiences have been that the bushings in an old truck had been neglected so much/long that the wear/looseness in the bushings was enough to cause the king-pin to become loose in the axle.

I'll defer to those with more experience on the axle wear although I don't understand how it happens since the king pin shouldn't rotate with the wedged pin in place. It was suggested to me that new bushings would probably fall thru the spindles because wear in those eventually effects the spindle bores as well. That was true with mine. The local shops did not have a hone long enough to rebore both sides of the spindle at the same time and told me they couldn't guarantee absolute alignment. I sent my spindles to Sid's Axles who did have the proper equipment to hone them for the oversize bushings. Everything went back together like new.

I have wondered the same thing.
Carl

Its not rotation that wears the axle eye its the rocking back and forth that egg shapes the hole. If the pin gets a little loose or the truck had a real hard life on hard roads the pin can move left to right and pivot on the lock pin.

If the old pin cleaned up and de-bured slides in fairly tight and doesn't wobble get std pins. If it wobbles at all get over size pins and ream the axle eye to a slip fit just as you would a pin bushing. If you do pins on an axle with a bad eye it won't change the shakes and wandering you currently may have.

Well-described, Dave. Thanks (my comment above was a little too terse)

The issue I have, is the bushings are loose in the spindle. The standard pin is nice and snug in the axle. Any one ever find an oversize bushing? Would be nice not to change the spindle that is fine otherwise(ain't no body making "new" spindles so far). 1/2 ton in my case. I have thought about getting the bushing knurled...any one do that? Spindle hole is straight, true, and just a bit loose. Bushing will press in and through with my thumb. Nice and snug for a few hundred miles, then the sloppy comes right back. Ugh.

Knurling the the outer surface of the bushing did not work for me.

I think that someone might have posted a MOOG part number for an over-sized outer-diameter that worked with a .010 over-size king pin. I cannot find the post.

http://www.moog-suspension-parts.com/

One option is use loctite bearing retaining compound to fix the bushings in the spindles and take up that small amount of slop. This, while not how the 1/2 ton axles were intended to be, is no different than kingpins and bushings on all the larger trucks. Some searching will turn up much discussion and more detailed how to.

Grigg

I have tried that on the pickup we are restoring (after reading an earlier post by you, Grigg). My fingers are crossed, but it might be more than a few years before the body parts get put on the ready-to-go rolling chassis (and drivetrain).

Thanks

(by the way - off-topic - I finally got the COE registered - the last two owners have passed-on but they did not pass on to me properly transferred/dated/signed titles/registrations)

You can have any competent machinist make you a set of larger OD bushing from brass and fit them to the spindle, then hone to the correct pin size.

Dave,

Probably so - that same machinist would have to also correctly bore the spindle/knuckle.

If anyone knows such a machinist/machine shop and has had it done. how much did it cost?
Also, what was the part number of the bushings?

Found this in the Tech Tips section. Might be a solution...but requires tooling I don't have. No PN so it would be a hunt and seek operation. http://www.stovebolt.com/techtips/spindlebushing.htm
Some one posted...an Oldsmobile PN that was oversize on the out side and standard for the inside diameter. But I can't find that post. I think it was a RockAuto PN if memory serves me(That is a big if).

This is exactly the situation I pointed out in the 9th response to this thread. I doubt that the rounded out spindle holes are perfectly round. Two of the local machinists I consulted said they could hone the spindle bores for oversize bushings but did not have a hone long enough to do both ends at the same time and there could be a slight mis-alignment issue. I sent my spindles to Sid's Axles http://www.droppedaxles.com/ because he has the right equipment to do the job properly and supplies the correct bushings as well.

The NAPA part number for the oversize pin kit and bushings for it but with standard OD is # 262-1432.010 This also includes ball thrust bearings. Several part numbers will work and some kits come with bronze thrust washers, standard size # 262-1432 for example. So be sure the kit you order is the kind you want, not just the first thing the parts guy says will fit.