I picked up my 1920 735 last week and I am working on putting a working engine together out of parts. I have almost two engines. One has modern bearings but the gear on it is pitted and worn. The other has the original style bearings and the gear on it looks almost new. So I was going to disassemble them and swap out the gears. I read that it takes a 50 ton press but I wanted to know if there is anything other than a tight fit and the key that holds them together. I don't want to break something using brute force because I was ignorant. Here are pictures of the two gears.

Thanks Todd

Hi Todd,
I'm working on a 10 Hp Stanley Engine myself. Is there an option to just put the newer bearings on the crankshaft that has the good gear? To me, this would be an easier thing to do. Either way, you may want to consider new crank throws also.

To answer your question, there isn't anything else regarding the press fit and keyway. My understanding is that it is around a .003 - .005 diametral press fit (please verify with another source before installation). If you decide to press off the gear, try ice cubes on the hub and heat the gear to help. Careful, there is a lot of surface area and energy to remove. You need to re-install with temperature differential. In other words, freeze the crankshaft in your freezer and heat the gear to ~500 Deg F in your oven. Good luck!

Hope this helps,
Rick

Todd, The engine gear presses off the crankshaft in only one direction. Get it right.

I don't think I can just swap the bearings as I am assuming that there has been machining to fit to the inside of the bearing. I will try the heat differential.
Todd

Rick.H Wrote:
-------------------------------------------------------
> Hi Todd,
> I'm working on a 10 Hp Stanley Engine myself. Is
> there an option to just put the newer bearings on
> the crankshaft that has the good gear? To me,
> this would be an easier thing to do. Either way,
> you may want to consider new crank throws also.
>
> To answer your question, there isn't anything else
> regarding the press fit and keyway. My
> understanding is that it is around a .003 - .005
> diametral press fit (please verify with another
> source before installation). If you decide to
> press off the gear, try ice cubes on the hub and
> heat the gear to help. Careful, there is a lot of
> surface area and energy to remove. You need to
> re-install with temperature differential. In
> other words, freeze the crankshaft in your freezer
> and heat the gear to ~500 Deg F in your oven.
> Good luck!
>
> Hope this helps,
> Rick

Is it apparent which way to press? Is there a shoulder that butts against the gear? I am assuming that I need to remove the crank first or can I press it all out in one go?

Thanks. Todd
SSsssteamer Wrote:
-------------------------------------------------------
> Todd, The engine gear presses off the crankshaft
> in only one direction. Get it right.

I don’t remember there being only one direction to press the shaft out.
You press off the crank webs then the eccentrics and the drive gear.
I only did it once, I took mine over to a friends shop knowing he had a very large press.
It also helped that he also had a box of short length of harden and ground shafts and spacer blocks.
The thing that I remember most is there was a large tractor flat bed with a forty-five foot 12 inch shaft on it. A Navy job. The shaft was over hanging the end of the trailer by about six feet.
I ask why it was their knowing he had no why of handling it. He said he had just cut a key way on the end. I said really???
He had rolled out a Bridgeport underneath the shaft and jacked it up under it and chained the table to the shaft. He machined the keyway by moving the machine back and forth on the table. There is always more then one way to skin a cat.

Rolly

Good luck with it Todd

My experience with the type 6, type 7 and type 8 engines, all crank shafts press off in only one direction. Pull the crank throws first, then you can see which way to press the shouldered crankshaft out.

Hi Todd,
Your crankshaft assembly should look like this as pictured in the first 2 pictures. Use the biggest gear pulling tool at Harbor Freight to pull off the crank throws. I was able to do this on my 20 Ton Press. Picture of tool used in another application...you should get the idea. Then you should have a situation like the last picture. When you are at this stage, you should be able to determine which way to press off the gear. The gear might have the eccentric right on the gear as an integral part. By the way this is why I suggest the change of the bearing instead...something to think about.
Hope this helps,
Rick

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File Name	File Size		Posted by	Date
IMG_4993.JPG	105.8 KB	open | download	Todd M	10/02/2021	Read message
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