King pin replace

B

bucket-o-rust

Senior Member
Will the king pin reamer that Snyder's catalog has for sale work ok for a do it youself at home mechanic. I have a new old stock king pin set that I will be using?
 
I would take it to a local machine shop and have it honed. It will be better and if you are doing one it might even be less expensive.

Charles Stephens
 
Yes, did it. Be sure to replace the bushings in a sequence. After pressing in one new bushing, run the reamer through the old bushing into the new bushing so the bore is centered. After pressing in the remaining bushing run the reamer through the "just reamed" bushing to ensure the remaining bushing is reamed true. Take your time, use cutting fluid, and keep the reamer free of chips to the max possible (make the cut in steps and clean the reamer in between cuts). Should have a nice fit afterwards. Good luck.
 
I agree with all the suggestions above. There is nothing worse than going thru a lot of work only to find that you have kings pins that are slightly loose and you haven't even used them yet. Years ago I did this job at home and I borrowed an adjustable reamer. You would turn an adjuster to advance the knives and then lock them in place before use. If I knew what I was doing, it should have done a good job. I also found that the pins can be poorly manufactured, being out of round. You end up taking too much material out of the bushings when in fact you are chasing high spots on the pins. It is best to let a professional do the job. Ed
 
To consolidate a lot of what's above and maybe add in some additional thoughts: what you want to end up with is kingpins and bushings that are concentric but differ in diameter by a very small clearance amount. By using the reamer you are assuming that the kingpins are straight, smooth and concentric, and at the reamer size is appropriate. Yes, you're using NOS, so the quality of the kingpins makes at least their dimensions more reliable. But by having these honed in by a machine shop you are not only avoiding spending $150+ for a reamer you may use on only one or two projects, you are betting that all the dimensions and alignment are proper. Last time I rebuilt a Model A front end was in 1970, and I reamed the bushings and everything fit fine. Now faced with doing it again (for likely the last time in my life!) I'll likely sub that out.

JayJay
 
If you do use a reamer, be sure you never turn it counterclockwise. You can ruin it with one little twist backwards.
 
A good machinist can do the job and give you peace of mind. Most likely at less cost than the reamer.
 
Whenever this topic comes up, people chime in saying the bushes should be honed. NO! we are looking for a ROUND hole on size. Honing will not make an oval shaped hole round. A ream will.
I ream till they are still a bit tight, then use the part of an old king pin that was in the axle and some lapping paste to burnish them to a good fit. I end up with contact all the way around the bush, not just on the tops of ridges left by the ream. A thorough clean before assembly is a must
 
bucket-o-rust said:
Will the king pin reamer that Snyder's catalog has for sale work ok for a do it youself at home mechanic. I have a new old stock king pin set that I will be using?
Click to expand...

Yes! That is a precision reamer, It will give you a perfectly round hole of the correct size.
All the stories about ridges and chatter were done with adjustable and straight blade reamers.
They were reamed at the factory.

Bill
 
J Franklin said:
A good machinist can do the job and give you peace of mind. Most likely at less cost than the reamer.
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Emphasis on a GOOD machinist. He will give you a good final fit. I don't know how cheap the reamers are or your skill, but when I had mine done it was cheaper than buying the reamer and he placed the bushes also. I supplied the parts.
 
Synchro909 said:
Whenever this topic comes up, people chime in saying the bushes should be honed. NO! we are looking for a ROUND hole on size. Honing will not make an oval shaped hole round. A ream will.
I ream till they are still a bit tight, then use the part of an old king pin that was in the axle and some lapping paste to burnish them to a good fit. I end up with contact all the way around the bush, not just on the tops of ridges left by the ream. A thorough clean before assembly is a must
Click to expand...

You are getting a good fit by being slow and precise in your work. I'm sure you would agree that many are not that careful. I let work out my door when it makes sense. I have saved parts that others didn't want to touch, but I am happy letting a shop do my machine work. My machining experience ended in High school. But as a trade off I am a reasonably good mechanic and do my own paint too.
 
rich b said:
Are you saying a Sonnen pin hone does not make round holes in kingpin bushings?
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I had to google to see what a Sonnen Pin Hone was was. This is what I found https://www.youtube.com/watch?v=j5UqmpMME88 which looks VERY agricultural to me. Those big end bearings are not likely to be square to the axis of the con rod nor round nor parallel. Hand held is not good enough.
Apart from the difficulty keeping square and parallel, the hole may be round if it was round before using that machine. As I said, a hone will not make an oval hole round. It will only follow the shape that was there before the hone was used.
 
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Synchro909 said:
I had to google to see what a Sonnen Pin Hone was was. This is what I found https://www.youtube.com/watch?v=j5UqmpMME88 which looks VERY agricultural to me. Those big end bearings are not likely to be square to the axis of the con rod nor round nor parallel. Hand held is not good enough.
Click to expand...

Wrist pin bushings are reamed with a precision reamer in a fixture to maintain alignment in aircraft engines.
if precision reaming is good enough for aircraft wrist pin bushings it's good enough for king pin bushings.

Bill
 
My kingpins are the original and a bit worn to about .810 diameter. I bought a 13/16 reamer off eBay (.8125 diameter). I replaced the most worn bearing first and used the other one as a guide, then replaced the other bearing using the first one as the guide. The reamer flutes are long enough to go through both bearings at the same time. The reamer in good condition cost me 35.00 + shipping. Worked for me.
 
I just did my king pins using the Snyders reamer on my first Model A. Long time Model T guy (30 years) enjoying my new 28 Roadster. I followed the Les Andrews book. I pressed in both new bushings first, then did the reaming. The reamer has a smaller front end that does a preliminary reaming and keeps the reamer in line with both bushings as the second wider part of the reamer passes through the bushing. Flip the spindle over and do it again. Nice results, king pin fits nicely without play.
 
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