King pin advice

LizardsA

LizardsA

Senior Member
Howdy folks,
I have been disassembling the brakes on my '30 Sport Coupe, following the instructions in Les Andrews' Red Book.
On the step that removes the actuating arm, the instruction says the following: "With large pliers or pipe wrench rotate the king pin cup (top portion of the king pin) outward (toward front) enough to release the actuating arm"
My question arises from experiencing a great deal of difficulty on one of these king pin cups, where I literally had to use a hammer and punch to move it. What purpose does the king pin serve?
Is it meant to move freely, and if so, to what degree?
What would make it so stiff, and what damage could possibly be found?
Are there inspections I should be performing on the king pin, or is it better to just replace?
Kind regards
Mike
 
The kingpin is locked in place by the tapered locking bolt, so it does not move. The bushings on the spindle ride on the king pin, and will wear it some. Look for wear in the bushing area of the kingpin, and replace the kingpin if you have more than a few thousanths wear. The kingpin may be rusted in place, especially if the car hasn't been used or lubricated for years.
 
Tom out of curiosity, is it ever feasible to build up a worn king pin with weld, turn it down, and re-use? or is that too much trouble to go through? Would that kind of heat applied make the king pin unsafe?

Just thinking of the 'original parts vs. repop' issue and the originals that wind up buried on a shelf or tossed.
 
The king pin is a precision ground shaft.

Why risk problems?

Finding NOS Ford is not difficult and there always seems to be stuff out there. There are also lots of modern and NORS options. One should never have to consider anything but new. Plus the cost of doing the work far exceeds what it takes to get a NOS or a good NORS set.

Buy new and be sure to hone the bushings to fit, not ream them. That will give you the best results.
 
Kevin in NJ said:
The king pin is a precision ground shaft.

Why risk problems?

Finding NOS Ford is not difficult and there always seems to be stuff out there. There are also lots of modern and NORS options. One should never have to consider anything but new. Plus the cost of doing the work far exceeds what it takes to get a NOS or a good NORS set.

Buy new and be sure to hone the bushings to fit, not ream them. That will give you the best results.
Click to expand...
what do you use to hone the kingpin bushing? thanks for any help
 
I used a kingpin reamer. It was worn so I had an old brake master cylinder hone so I used that to get the extra thousand oversize
John
 
I also have used a reamer for years on my model A's. The Ford service departments used reamers back in the day.
 
Glad to find this topic. I just bought a nice front axle at an auction last week. My plan is to first get it powder coated, then build up with mostly new parts. the King pin section has me looking for the best ways of doing the job right myself. The reason for a new axle is that some time in her past, Some ding dong welded studs so to mount modern shocks. I find it to look sooo ugly. Any help on specs and procedures would be great.
 
While people have been reaming for decades, your most accurate fit is found with honing a precision round hole. This is done with a Sunnen hone (or equivalent) at a machine shop.

Reamers can leave high spots, especially straight reamers. These high spots will wear rapidly leaving you with a little bit more wear then you would get with the honing. The honing machines were not in the field back in the day so the reamer was what you had, today there is better way with a hone. I would guess that they were honed in the factory.

Keep in mind the reamer used properly does a good job. Honing leaves you with a more accurate and round hole. If you have access to a hone you would be better of using it.

As for that axle you bought at auction. You had best check for straightness.

Front Axle Checking

Also check the king pins in the holes. Sometimes they are loose, they should be snug. The mount areas for the wish bone should not have wear. The powder coater best plug the holes as you do not want to have to remove the powder coat from inside the holes.
 
I concur with kevin and Mitch as well, I use a sunnen pin home and it ream the bushings perfectly. Try and search out for a machine shop in your area
It is the simplest if operations to do
I know I'm a little spoiled with the equipment but thankful I have them.
Brake shafts , etc should all be reamed if necessary for a precision fit
Hopefully you will find a shop in your area
Larry Shepard
 
Kevin in NJ said:
While people have been reaming for decades, your most accurate fit is found with honing a precision round hole. This is done with a Sunnen hone (or equivalent) at a machine shop.

Reamers can leave high spots, especially straight reamers. These high spots will wear rapidly leaving you with a little bit more wear then you would get with the honing. The honing machines were not in the field back in the day so the reamer was what you had, today there is better way with a hone. I would guess that they were honed in the factory.
Keep in mind the reamer used properly does a good job. Honing leaves you with a more accurate and round hole. If you have access to a hone you would be better of using it.

As for that axle you bought at auction. You had best check for straightness.

Front Axle Checking

Also check the king pins in the holes. Sometimes they are loose, they should be snug. The mount areas for the wish bone should not have wear. The powder coater best plug the holes as you do not want to have to remove the powder coat from inside the holes.
Click to expand...

Kevin, I think you'll find they were reamed at the factory.
Bill
 
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If you don't have a reamer and only plan to own one model A it will probably be just as cheap to find a machine shop ,if you can and have them honed. I won't argue which is best but if they reamed them at the factory and at the Ford service departments, reamers are good for me. Automotive mechine shops are not as common as they once were. I for one was very pleased when Brattons offered correct reamers for all of the model A bushings and I bought them all . I have a collection of model A's . I built some from parts and I am able to do all of my own work. Before these reamers were available from some of the model A venders, many model A home mechanics had to resort to dowels with sand paper wrapped, rat tail files , brake cylinder hones and all sorts of make shift merhods that were never acurate by any stretch of the imagination. Reamers cut like a knife to a set measurement. If the bushings are reamed to the sizes that meet Ford specs it is likely that the bushings will last a lifetime for the average model A owner if properly greased. In my opinion most are only used fior fun and not for primary transportation. I've never had a problem with the bushings that I have reamed And we can enjoy driving our model A's at any time that we please. Those of us that have read this forum for any length of time know one guy thats model A has been in pieces for probably a decade or more. This guy knows it all about the model A and of course his will be better than everyone elses when it is finished. Time waits for no one. I'm glad that I've got model A's that we can enjoy. I cranked up my september 29 and drove it down to the orchard and back today. I've owned it since I was a kid. What a blast, It always raises my spirits to drive the miodel A's even if I feel bad to start with. Theres nothing like the chick-ah-lunk sound.
 
all this advice is tops but I bought my a tudor to fix as best i can to specs as I believe that its best to do it your self just my opinion as I glean tons of a info from this site keep up the good work
 
a-bone newby said:
all this advice is tops but I bought my a tudor to fix as best i can to specs as I believe that its best to do it your self just my opinion as I glean tons of a info from this site keep up the good work
Click to expand...

You've got the right idea. Do it yourself, you'll enjoy fixing it as much as driving it.
Bill
 
bbrocksr said:
Kind of like mechanical brakes and babbit bearings.

Bill
Click to expand...

Hey Bill,
That make me smile;) ! I've never heard anyone here say Fords old ways were not necessarily good..go figure :) !

Well, I did mine with reamer , like Ford did, and it came out great and still does not exhibit any excessive clearance.
 
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