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Discussion Starter #1
Good day everyone
I am new to this forum and was looking for a bit of information on my Gravely LI.
I am wondering what year it is, one of my neighbors told me it was 1959 vintage, but the hood looks newer.


A2F57AF9-0BA7-479B-BB76-FEA3DFC8A34B.jpeg 559FDBEF-1BC2-43DE-B312-5AF4501D45E8.jpeg

Any information on this machine would be most welcome!

Thank you!

-BobC
 

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See Requested L/C Serial Number Info.

M43021 says 1959. Yes, somebody stuck a newer hood on there.

I also have '59 LI, one of my better runners :)

Check out gravelymanuals.com. There's lots of good info there.

What other information are you looking for?

And BTW welcome to MTF!
 
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Discussion Starter #4
Might sound silly, but am looking for advice on proper operation of the tractor. Specifically the sickle bar. I just purchased the bar and want to make sure I a using it correctly.
The only other attachment I have is the bush hog for it.

I will check out the gravely manuals site and see what is there, Thanks!

-BobC
 

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Might sound silly, but am looking for advice on proper operation of the tractor. Specifically the sickle bar.
Nothing silly about it. These old machines work great, but take a bit of technique to really get the best out of them.

For general information, see the owners manuals. They'll give you a lot about basic maintenance, care and feeding, etc. A general thing to remember: These machines were built in a time when the emphasis was on robustness and getting the job done, rather than being user-friendly. They wouldn't be allowed today, as there are no safety features like operator presence switches, non-removable guards, stuff like that. Always respect the machine, and know what you're doing before you do it. It will reward you with solid service for many years.

Re sickle-bar in particular: The main thing is to keep the RPMs pretty low. The gravely engine is a torque monster, and will continue to chug along at very low speeds compared to modern stuff. The sickle bar oscillates back and forth, and if you try to run it too fast, eventually it will shake itself apart. Pick a setting about 1/4 to 1/3 throttle and let it it do its thing at its own speed, don't try to rush it.

You'll also want to check the fit of your cutter bar. If it's sloppy, IOW if there's space between the moving blades and the fixed cutter plates, it won't work as well, and can jam. If you have good sharp blades on it, and the cutter bar is tight, it will cut through nearly anything, up to about 3/4" saplings.

Good luck, and we want pix!
 

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Discussion Starter #6
The teeth on the sickle bar need some attention, need to look up how to sharpen them, if they can be sharpened. The gentleman that sold me the bar indicated that the center section of the cutter bar should be tightened up a bit.
Will need to put a bit of time in it but with a potential storm coming for a visit the middle of the week, will need to get my Onan ready for operation too!
So many projects and so little time!

Thanks jrd!!

-BobC
 

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If it operates as any bar mower I have operated there are a few things that will create a big headache. jrd mentioned the bar itself and engine speed. The grass you may try to cut is another.
Wet grasses may plug it in a heart beat. Stringy marsh type grass will be a struggle. Your deck type mower doesn't like it the sickle even less. Dry ridged stem grass will go threw it like a dream. Same with fingers, pet legs and wildlife. So if you plug the bar shut the tractor off before putting any body parts any where near the bar.
 

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The teeth on the sickle bar need some attention, need to look up how to sharpen them, if they can be sharpened.
The sickle bar uses the same teeth (and I think the same rock guards) as any number of farm (big tractor) sickle mowers back in the day. You can get replacements at places like TSC, or ebay. Installing them can be a pain, as you're supposed to use iron rivets. Don't use bolts!

There was a gadget sold as the Sickle Grinder, which had a hand crank, a grinding wheel, and a clamping arrangement, for sharpening, but I can't find a picture of it now. I actually have one somewhere in my gravely parts, but I've never used it.

The easy way to sharpen sickle bar teeth: A belt sander (!) Set the sander upside down on a bench, lock it on, and carefully maneuver the bar so the you're dressing up one edge of a tooth at a time. It generally only take 10-15 sec of grinding to get back to a sharp blade.

I'm sure the purists are turning over in their graves to hear about such a technique, but it works as long as you're careful.
 

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Discussion Starter #9
The sickle bar uses the same teeth (and I think the same rock guards) as any number of farm (big tractor) sickle mowers back in the day. You can get replacements at places like TSC, or ebay. Installing them can be a pain, as you're supposed to use iron rivets. Don't use bolts!
Hi jrd.....
You mention not using bolts, I saw on a couple of parts sites, replacement teeth kits that include “specialized” bolts that are supposed to make doing this type of maintenance easier.
Curious, besides the obvious shaking of the bar, why should you NOT use bolts?
Curious minds want to know :)

-BobC
 

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A standard bolt is .002-.004 undersize, so that you can get it through the hole. That's fine if the force on the bolt is in tension, IOW pulling on the bolt. In the case of sickle bar teeth, all the force is in shear (sideways to the bolt). Because the bolt is undersized, with a bit of force, the tooth can work back and forth a little. Once it starts working, it will enlarge the holes until it's really slopping around.

A rivet also starts out a bit undersize, but when you install it, you crush it. That causes the body to expand and totally fill the hole, no room to slop back and forth.

I'm sure your specialized bolts are closer to the hole size, to minimize the clearance. It's still not as good as a rivet, because you're not totally filling the hole.

The iron rivets are a pain. You really need a proper concave bucking surface, and a small sledge to properly mash them down. Or a big enough hydraulic press, my little 50-ton press won't do it. If you don't want to mess around with it, I'd find a local machine shop that wants an interesting hour's work.
 

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To think I use to do that in the field with nothing but a claw hammer, a punch and the mower frame. We always carried a few extra teeth when mowing hay.
 

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To think I use to do that in the field with nothing but a claw hammer, a punch and the mower frame.
+1

You're clearly a better man than I am :)
 

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Discussion Starter #14
A standard bolt is .002-.004 undersize, so that you can get it through the hole. That's fine if the force on the bolt is in tension, IOW pulling on the bolt. In the case of sickle bar teeth, all the force is in shear (sideways to the bolt). Because the bolt is undersized, with a bit of force, the tooth can work back and forth a little. Once it starts working, it will enlarge the holes until it's really slopping around.

A rivet also starts out a bit undersize, but when you install it, you crush it. That causes the body to expand and totally fill the hole, no room to slop back and forth.

I'm sure your specialized bolts are closer to the hole size, to minimize the clearance. It's still not as good as a rivet, because you're not totally filling the hole.

The iron rivets are a pain. You really need a proper concave bucking surface, and a small sledge to properly mash them down. Or a big enough hydraulic press, my little 50-ton press won't do it. If you don't want to mess around with it, I'd find a local machine shop that wants an interesting hour's work.
Good information jrd, thank you.
Time to see what I can do on my own or see if one of the local farm machine places does this work now and what they would charge.
I was never good at mashing rivets when I was working on cars for a living. I recall seeing bolts with serrated shanks near the head that were supposed to counter act the tendency to loosen and enlarge the hole.
Lots to think about!
:)

-BobC
 
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