King pin fit

[Rich Bowes]

How should new king pins fit in the spindles. Should they be very tight, or should there be any play? should there be any clearance around the king pin, between the king pin and the spindle?

[Werner]

Guten Abend Rich. The fit is correct when the oiled components glide smoothly. This corresponds to approximately 5/100 mm clearance.

[Patrick L.]

I ream both bushings together to .003-.004". Some specs will say .001" but I find them too tight to take grease.

[duke36]

The vendors I believe still sell the bushing reamers.

[Mulletwagon]

After pressing in new bushings new king pins will not fit until the bushings are reamed to .8125 inch. After reaming the pins should slide smoothly with no perceptable play. The actual clearance is probably less than .001 inch - like wrist pins. When reaming, a good practice is to press in a single new bushing and ream it using the old remaining bushing as a guide to ensure the bore is reamed concentrically, then press in the other bushing and ream again. When reassembling be sure to shim the assembly so the entire load is on the thrust bearing. Take your time and do the job right !

[Dodge]

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I ream them a little under size then hone to fit just like she likes it.

[aermotor]

Originally Posted by duke36

The vendors I believe still sell the bushing reamers.

The one's I have seen are too short to go through both bushings at once. A local machine
shop can hone them in for a couple bucks.

John

[daren007]

Save time nd money plus aggravation. Have your local machine shop hone the bushings.

[Mulletwagon]

Originally Posted by aermotor

The one's I have seen are too short to go through both bushings at once. A local machine
shop can hone them in for a couple bucks.

John

This is a good one from Snyder.

https://www.snydersantiqueauto.com/P...PINS-ONLY-PAIR

[100IH]

Best practice is at the machine shop and only if they have a Sunnen pinfiting machine or equivalent from Italy This will hone both bushings at the same time in alignment. Wheel cylinder hones can get out of round and no alignment. The special reamer, some alignment but no control over the final clearance.

[old31]

Based on the price from Snyders I would think it would be cheaper to have a machine shop do it.

Why buy a $160 reamer if you are only going to use it once or twice.

[Cape Codder]

How come in is not addressed in THE book : Model A Ford Service Bulletins Complete?
Didn't they ever change King Pins? HA! HA!

[CWPASADENA]

Have a Machine Shop do it.


I recently bought on eBay an old adjustable hone set specifically made for King Pins. It came with a whole box of new abrasives which will hone all the king pin bushings I will ever want to do and then a lot more. I paid about $35.00 and it really works well.


Before I found this, I always had my local machine shop hone the bushings.


Chris W.

[Werner]

Hello precision mechanic.

As a low-cost compromise, I rub the bush bearings with a hone stone brush (+/- $ 15.00) for hydraulic brake cylinders. They are very cheap. But they are sufficient for such simple requirements.

[Tom Endy]

years ago I bought a king pin reamer from Bratton's that is long enough to ream both bushings in line. I have rebuilt six or seven front ends and used the reamer. I have never used a hone. I seem to have had good results with just using the reamer. The problem I had was trying to figure out what to do with all the bearing shims. I spoke with Les Andrews and he educated me about the geometry of the front end. The attached article is a para-phrase of Les Andrews conversation. The procedure has worked for me.

Tom Endy

[Synchro909]

The best way I've found is to reem the bushes with a pilot on the reemer so they are in line. I stop while they are still a little too tight and use some valve lapping paste on the unworn part of the old king pin(the part that was in the axle) to bring them to a point where I can push the new king pin in with my finger. Clean the bush thoroughly before final assembly. If it is too tight, the car will be all over the road and you'll have to take it apart and do it properly (after you change your underwear!).

[J and M Machine]

Originally Posted by Rich Bowes

How should new king pins fit in the spindles. Should they be very tight, or should there be any play? should there be any clearance around the king pin, between the king pin and the spindle?

Hello Rich:
The pin fit should just slide in: to quote a "Perfect fit"
Any machine shop that has a Sunnen hone can do them for you to achieve the perfect fit.

[old31]

I just brought my king pins to a shop that has a Sunnen. Mine slide in with a tiny bit of friction.

They charged $45 per side.

[ryanheacox]

Was going to get mine honed until I stopped into A&L to pick up some parts and he gave me a nice piloted reamer to use. It worked great and the surface finish looks nice. Test fit of an NOS kingpin confirmed a nice tight fit.

[ryanheacox]

Originally Posted by old31

I just brought my king pins to a shop that has a Sunnen. Mine slide in with a tiny bit of friction.

They charged $45 per side.

$90 seems pricey for 2 spindles but then if they charge an hour of labor minimum I guess that makes sense.

[redmodelt]

If the king pins turned like a shaft I could see honing, but they only turn a few degrees each way. Reaming works just fine for us.

[Rich Bowes]

Thanks to everyone who replied.


I decided to take my car's spindles to a local machine shop, where they removed the old bushings, pressed in new ones & reamed them out so there was .001 of an inch clearance around new king pins.


Worked perfectly! King pins slid in easily but are just snug enough.

[rotorwrench]

I don't hone soft phosphor bronze bushings. The silicon carbine particles embed themselves into the soft metal and cause premature wear. I use align reamers for the size I need. 7/8" for Ford & 15/16" for Mercury generally. These reamers only have a small amount of adjustability to do the job. I get a light press fit that can easily be done by hand with just enough stiffness that they will stay in the bore under their own weight.

If you hone them, I would recommend brushing the bearings out with a stiff tooth brush and soap & water after the hone job. At least some of the particles will be removed that way. I hone steel bushings for the Bell 47s but it sure isn't soft metal.

[gdmn852]

Hello you would think that some of the larger vendors would offer rebuilt spindles reamed and fitted similar to the steering arms .MGB ,s also use kingpins and rebuilt sets are standard catalog item .

[Chopd48panhead]

What did they charge for the work. The $90 figure from above is making me think to do it myself.

[BRENT in 10-uh-C]

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Originally Posted by rotorwrench

I don't hone soft phosphor bronze bushings. The silicon carbine particles embed themselves into the soft metal and cause premature wear. I use align reamers for the size I need. 7/8" for Ford & 15/16" for Mercury generally. These reamers only have a small amount of adjustability to do the job. I get a light press fit that can easily be done by hand with just enough stiffness that they will stay in the bore under their own weight.

If you hone them, I would recommend brushing the bearings out with a stiff tooth brush and soap & water after the hone job. At least some of the particles will be removed that way. I hone steel bushings for the Bell 47s but it sure isn't soft metal.

Ewww, ...I think this is very misleading. To begin with, most commercially manufactured Spindle Bolt (King Pin) Bushings are manufactured from a 660 bronze with tin added for strength. These are not soft, ...unless you are comparing them to steel I suppose. Phosphor Bronze as a whole may, -or may not be the right material depending on the composition. The only bronze material that I know of that does not hone well is the 841 that is sintered from powder. It is what many refer to as Oilite Bronze which is self oiling. Sunnen manufactures many machines specifically for sizing bronze bushings.



Something I think is often overlooked in the reaming vs. honing debate is a reamer can do a good job on bringing a bushing to a finish size too however most reamers are not designed to ream both bushing simultaneously, -often times they are dull, ...and most reamers are not used correctly by the mechanic with a continuous motion to avoid chatter and ridges. Because the Honing machines that we use are adjustable during the process, use a flooding lubricant to keep the stones lubricated and clean during the process, and the mandrels are designed specifically to hone all the bushings simultaneously, they tend to do a slightly better job over the reamer. That is why I use a hone to size the bushings, but in reality a hone is not required.

[rotorwrench]

Phosphor bronze is common in nearly all bushing materials for the type used in transmissions and other load bearing hinges. There is nothing misleading about what I stated. I choose not to hone the stuff but I don't dictate what others should do. That's why I recommended that folks brush out a honed bearing surface if they choose to go that route. That will at least remove any loose particles that may be lightly embedded in the surfaces.

I have purpose made reamers just for king pins and I don't use them very often so they are still very sharp even though they are pretty old. They align with a pilot for both sides and go all the way through in alignment. I keep them well oiled and store them in their original boxes when not in use.

[larrys40]

I have honed hundreds of them. It’s common sense to clean them and lube them prior to assembly. amazing the comments. I’m with Brent on this. I’ll take a hone fit over a reamer any day.