King Pin differences

[Aok]

I have some play in the king pins on my 31 coupe will need to be replaced soon. I was checking prices I see model A vendors have them around $70-80 but Napa has them for $154 big difference. Having done some work on 50's vehicles I know there is a difference in materials used. Just wondering if any one knows if any difference in the model A kits ?
2nd question does anyone sell the reamer at a better price then $150 +/- that the venders get or them which is a lot for a reamer that does not even include a driver for the bushing.

[Rich in Tucson]

Just used a set from Bratton's on someone's car and they were of excellent quality, even the bushings. As far as I now there is only one manufacturer currently. I highly recommend that you have the spindle bearings pin honed by a machinist rather than use a reamer, it is relatively cheap and you won't wonder why your reamed bushings have noticeable clearance after a few thousand miles.

Show the machinist the parts in proper assembly orientation, including where the bearing goes, so the proper area of the spindle bolt can be measured for the honing.

[Kevin in NJ]

You should never ream the bushings.

The reamer leaves wavy surface that feels tight. When put in the car and used the high spots wear quickly giving you a slight amount of play.

Properly honed the bushings will be very round and in line. They should be snug such that the pin needs to be twisted through the bushings some. If the pin drops though then they are too loose. Keep in mind the shop should not charge as much as it would cost you to buy the reamer.

[glenn in camino]

I restored most of my cars back in the 70s & 80s. I'm pretty sure they were all done with a reamer and have never been a problem.

[Ca. Kid]

Just had mine done at a local machine shop that specializes in old cars.They installed my bushing and honed with a Sunnen hone for $40.

[wrndln]

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I don't think reaming the bushings will cause any problems at all. It has been done thousands of times over the years. Our model A club has a tool loan program that has lots of model A tools that can be borrowed for free including a nice kingpin reamer. If you have a local club, maybe the club has a tool loan program or possibly a member has a reamer that you can borrow.
Rusty Nelson

[Kevin in NJ]

Again,

Reaming works, but not as good as you really want it to work. Been done thousands of times, but honing is the much preferred over the reamer.

Reaming fits tight at first, but will rapidly gain a few thou of play that will last a long time. So you go through all the trouble of putting a bunch of new parts in for a tight steering and then end up with some play. Not much, but play.

When you hone the bushings will stay tight for a much longer time.

So it is your choice. Tight for a long time or tight at first and then a little bit loose for a long time.
Personally I like to have my steering as tight as possible so I have honed bushings.

PS, not trying to offend, just trying to educate.

[James Rogers]

I agree with Kevin. Would you expect your engine builder to ream the wrist pin bushings in your new engine? I don't think so. If you did the engine would be clattering in short order and you would be very unhappy when he told you that is just the way it is.

[pat in Santa Cruz]

I've done both and prefer the feel after they have been honed. I won't go back to reamers.

[J and M Machine]

We also hone them since we have the machine to do so as honing is far superior over reaming.You are getting an exact and lasting fit. Furthermore I would caution people that the Kingpins supplied recently aren't the same size as a customer brought in a set and I proved to him that there is a difference.

We go one step further and magnaflux the spindles since there's always the chance of having a crack in one of them. They weren't supposed to last this long.

[Kurt in NJ]

The problem with a reamer on the A kingpin bushings has to do with the groove in the bearing, if the reamer has a spiral at almost the same angle as the spiral groove in the bushing it will create a 'chatter" as each blade of the reamer passes over the groove, if the spiral of the reamer goes opposite the spiral of the groove then you can get ok results.

Just as you can get a bad reaming job you can also get a bad hone job if the mandrel is damaged or the operator isn't paying attention

there is another method that isn't mentioned, there is a machine that bores the bushing, it is a dedicated kingpin boring machine, not very common now, but it can give results as good or better than honing ---if the tooling is in good condition and the operator knows how to use it.

On my A I used the reamer/driver, it chattered, the kingpins were very tight to start--too tight, by 10,000 miles they were too loose, I have 1/2"+ movement at the tread, and although it doesn't seem to cause any drivability problems with my car it is on my list of projects for the 25 year service (it has been 25 years since I have done anything more than minor repairs)

[RonC]

I understand honing by method is more accurate than reaming but can you really tell the difference? How much extra movement does reaming leave versus honing??

[Aok]

Thanks received a lot of good info here, considering the cost of the reamer I will have to consider getting it done by a shop but usually like to do things my self. Brakes look pretty good so may put off the king pins until fall and kick this around in my head a bit. Do plan on some front end work (tire rods and related) before it goes on the road some more questions to follow.

[1931 flamingo]

Cost: Reamer expensive, going to use it once (twice= 2 kingpins) in your lifetime.
Honing: pay the man, probably less than half as much as reamer, done.

Paul in CT

[Paul from Maine]

Originally Posted by RonC

I understand honing by method is more accurate than reaming but can you really tell the difference? How much extra movement does reaming leave versus honing??

I used a reamer on my kingpin bushings about three or four thousand miles ago. They still seem fairly tight. I have two more front ends out in the barn. I will probably use the reamer on them eventually. Probably honing is superior to reaming, but so far for me, the reaming seemed to do an adequate job. There is only one machine shop I know of in my local area. They don't treat me with much enthusiasm when I bring them jobs and they aren't cheap, so I bought the reamer and don't regret it. Probably where there is a little competition between shops, prices are lower and then honing would be the way to go, but I'll stick with the reamer.

[ctlikon0712]

I’m not here to gainsay anything that was previously said, and I have yet to do my own kingpins, but I have worked in precision machine shops for 15 years, and there are several ways that reamers can be configured that will give various results or finishes. A straight flute is the type where the cutting edges or flutes are straight up and down on the shank of the reamer. This will tend to give a series of high’s and low’s or ridges that can wear and loosen up over time. This can be countered by adding an odd number of flutes, say from 6 to 7 so that no two opposite flutes are riding up and down on the high’s and low’s at the same time, propagating the “chatter” condition. Another way to counter this is to have the spiral flutes. This takes the linear frequency out of the equation and along with an odd # of flutes should give a very satisfactory finish if used with the appropriate cutting fluid for the material it’s being used on. Now I’m not saying it’s better than Honing. But if you are going to do it yourself, get the best tool that you can and use good cutting oil. Some of the better oils I’ve seen are actually made from Emu’s oil. Don’t laugh! It works great with early type steels and iron.
If I give my 2 cents worth and you give a penny for my thought, then someone is making money on that deal! lol

[columbiA]

A few years back,I bought an old Sunnen pin hone at a swap meet.I took it all apart,cleaned & painted it It was missing the coolant tub & pump but i fixed that with a plastic tote & an aquarium pump.It works well & has paid for itself a few times over.

[James Rogers]

Back in the day crankshafts were reconditioned by scraping with a machine in the car using the starter for rotation. This was accepted practice and done regularly. Crankshaft grinders became more popular because they produced a better and more acceptable, longer lasting finish on the journals. This is the same with reamers and kingpins. Reamers do an acceptable job for the short run and to get the car out of the shop or to get it on the road but will not last. Honing leaves a much more polished finish that won't wear in the short term. If you want a lasting job that performs like it should, have them honed to fit. This is also the same theory that is used for the wrist pins and bushings.

[bbrocksr]

Originally Posted by James Rogers

Back in the day crankshafts were reconditioned by scraping with a machine in the car using the starter for rotation. This was accepted practice and done regularly. Crankshaft grinders became more popular because they produced a better and more acceptable, longer lasting finish on the journals. This is the same with reamers and kingpins. Reamers do an acceptable job for the short run and to get the car out of the shop or to get it on the road but will not last. Honing leaves a much more polished finish that won't wear in the short term. If you want a lasting job that performs like it should, have them honed to fit. This is also the same theory that is used for the wrist pins and bushings.

James,The method you describe was used as a repair when one or two rod journals needed regrinding, not the whole crankshaft
Why do the manufacturers ream bushings? Do you think they were honed originally in 1928?
Reaming or honing either one will produce an acceptable finish depending on the skill of the person operating the tool.
Wristpin and kingpin bushings have been reamed at the factories for years with excellent results.
Continental aircraft engine wristpin bushings are still reamed and they don't clatter and last the full time between overhauls
Their is a lot of difference between a precision reamer and a straight bladed adjustable reamer same as their is a difference between a precision hone and a handheld hone. The results of either are only as good as the operator. Bill

[bbrocksr]

Originally Posted by Kevin in NJ

You should never ream the bushings.

The reamer leaves wavy surface that feels tight. When put in the car and used the high spots wear quickly giving you a slight amount of play.

Properly honed the bushings will be very round and in line. They should be snug such that the pin needs to be twisted through the bushings some. If the pin drops though then they are too loose. Keep in mind the shop should not charge as much as it would cost you to buy the reamer.

Kevin, You say you should never ream the bushings,Thats how these cars were built at the factories and they lasted a long time when lubricated properly and the factory manuals specify reaming when replacing bushings.
Are the engineers that built these cars wrong?
Bill