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New triple gear pins?

Posted: Tue Sep 22, 2020 12:44 pm
by Steve Jelf
When I took apart my 1923 touring's transmission to replace a busted low drum, I found that one of the triple gears had seized and spun the pin. It wallowed out the hole enough to make the pin wobble quite a bit, so the flywheel is toast. So I went to the barn and picked out a "new" flywheel that looks like it will serve. In reading about installing new pins I read in the Transmission book,
As the holes in the cast iron flywheel become slightly enlarged when the steel shafts are withdrawn, it is necessary to use pins which are .003-inch oversize on the section of the shaft that presses into the flywheel. The use of .005 oversize pins requires that both the hole and the pin be measured and the hole reamed for a .002 press fit.
1 Is the reference to both .003 and .005 a misprint or is it about two different pins?
2 Are the new pins not tapered like the originals?
3 If they are tapered, how do you ream the holes with a taper? Or do you?
4 I assume the oversize is in the part of the pin that presses into the hole, and that the part which supports the gear and bushing is the original .675". Is that right?
5 I've seen different tolerances given for the bushings. How much is enough for the gears to operate with no chance of seizing?

Re: New triple gear pins?

Posted: Tue Sep 22, 2020 12:49 pm
by Jeepbone1
Give Bob a call over at Bob’s antique auto. He’s the one making the new pins. I just installed a set in my trucks flywheel. Nice machining and they installed very well. The end of the pin is slightly oversized to make up for the wear of driving the old pins out.

Brad

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 12:34 am
by Allan
If the bush seized on the pin and it spun in the flywheel, there was not enough clearance. This is one place where looser is better. I aim for .004"+ difference between pin and gear bushing bore. .005" is better than .003" Others may differ.

Allan from down under.

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 1:10 am
by Jeepbone1
Allan wrote:
Wed Sep 23, 2020 12:34 am
If the bush seized on the pin and it spun in the flywheel, there was not enough clearance. This is one place where looser is better. I aim for .004"+ difference between pin and gear bushing bore. .005" is better than .003" Others may differ.

Allan from down under.
I just set mine up with 0.004+ish clearance. Spin like a dream!

Brad

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 8:21 am
by J and M Machine
Just so everyone knows the triple gear pins are pressed out towards the magnets as the pressed portion is a different size in flywheel.
I would be aware of the hardness of the triple gear pins as we just did a flywheel assembly and the pins weren't hardened properly.
What I mean by this is when i received pins I noticed there were scratches on them. Typically the pins are hard but i took a file and went across the end and I was able to remove some metal. Meaning the pins are soft and will wear out prematurely.
As Mr.Jelf mentioned about wobbling I would also be aware that some flywheels that pins had pins replaced may be cracked.!
There is one triple pin hole that lines up with magnet and dowel hole of flywheel and they always crack there.

Just a word to the wise to be aware of quality of parts being made.

We set the triple gear bushing fit to .003"

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 9:12 am
by Dan Hatch
Look into ballizing or ball burnishing. This is for the bushings.

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 1:14 pm
by Dan McEachern
Just an FYI to all. I'm going to start production of the triple gear pins in the next few months. We have the steel on order for the 1st batch now. The pins will be made from a chrome-nickel alloy steel, properly heat treated and ground to size. This project is an outgrowth of making the special pins that are used with my needle bearing triple gear conversion. I've had multiple requests from experienced shops and individuals for a higher quality part, so I plan to make the 1st batch and see what the demand is. These will be available in various press fit diameters to accommodate different flywheel sizes. Thanks all.

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 5:51 pm
by Henry K. Lee
I received some sets from Dan and can say.., “WOW” very nice and quiet! Super work Dan!

Thanks,

Hank

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 9:50 pm
by AdminJeff
I can say the triple gear pin bearing upgrade from Dan is rock solid and worth a look. Just a really, really happy customer. The pic on the bottom is what it prevents, especially when you climb as many massive hills as I do.

Jeff

Re: New triple gear pins?

Posted: Wed Sep 23, 2020 10:53 pm
by CarreyDM
Jeepbone1 wrote:
Tue Sep 22, 2020 12:49 pm
Give Bob a call over at Bob’s antique auto. He’s the one making the new pins. I just installed a set in my trucks flywheel. Nice machining and they installed very well. The end of the pin is slightly oversized to make up for the wear of driving the old pins out.

Brad
Sounds like they know their stuff to make the best fitment!