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Discussion Starter · #1 ·
I ahve a rotary saw blade attachment and am trying to remove the saw blade without much success. Cound it be that the nut is reverse thread that is CW to loosen?
 

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If it's mounted on a left-handed mower, yes.

If it's a right-handed mower (blade rotates clockwise as seen from above) then it's a standard right-handed nut. Turn the nut counterclockwise (as seen from below) to loosen it.

If it's a left-handed mower (counterclockwise blade rotation as seen from above) then it's a left-handed nut. Turn the nut clockwise (as seen from below) to loosen it.

George
 

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The original Gravely rotary saw gearbox was different from the 30" mower gearboxes. They are RH thread.
 

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I had a heckuva time getting a new blade on my 18" saw.

I took a bunch of pictures, and intended to post a tutorial about it [maybe I'll get around to that some day], but, for now, suffice it to say that I went to Northern Tool and got a great big honking 24" pipe wrench to hold the washers, and a MASSIVE 3/4" breaker bar [with a 3/4" female to 1/2" male adapter] to make dadgum certain that I tightened it all back up properly.

The thought of that blade coming off [due to insufficient tightening] is pretty terrifying.
 

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That has got to be the most wicked attachment I've ever saw for the gravely's.

The one after that would have to be the giant chainsaw (I don't know the name of it)

Matt
 

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BTW, [at least for the modern deck heads] the cylinder in the middle, with the threading on it that the final nut ultimately screws onto, is a highly specialized piece of equipment, with lots of machining up and down its length.

I guess that Gravely must have anticipated that eventually the cylinder could go bad, so they made a replacement kit for it, which Richard in WV stocks [sorry, I don't have the part number in front of me right now].

It's not inexpensive [what custom parts are?], but if you're at all concerned about the quality of the threading on your cylinder [and whether it's still good enough to hold that final nut firmly in place], then you might think about giving Richard a call.
 

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Discussion Starter · #9 ·
Dummy question but I got the nut off but what appears to be a washer under the nut apparently is not a washer as it will not come off. How is it removed?
 

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The parts unique to the newer 18" saws are shown in this document from June of 1974:

http://www.oldgravelys.net/pdf/Circular_Saw_IPL_0674.pdf

But what you quickly realize is that the saw is just some specialized pieces inserted into [and around] a standard 30" mower head.

Now here is the March 1974 parts diagram for the 30" mower head:

http://www.oldgravelys.net/pdf/30_Inch_Rotary_Mower_IPL_0374.pdf

And here is a much more recent [but undated] parts diagram for the 30" mower head:

http://www.oldgravelys.net/pdf/30_Inch_Rotary_Mower_IPL.pdf

In the older diagram, the key parts are:

37 = Rotor Shaft, 19844P1
39 = #9 Woodruff Key, 124549
53 = Fixed Collar, 12861P1

And in the newer diagram, the key parts are:

37 = Rotor Shaft, 20676P1
32 = #9 Woodruff Key, 124549
38 = Fixed Collar, 12861P1

Now the Rotor Shaft is the heavily machined cylindrical part that I was talking about earlier, and it ultimately has the threads which the final nut screws onto [holding everything above it in place].

But it also has the "Fixed Collar" attached to it [via the "#9 Woodruff Key"], and I am pretty sure that the "Fixed Collar" is what appears to you to be "a washer... [that] will not come off".

PS: If the threading on the very end of your Rotor Shaft looks really awful, or if for any other reason you feel like the Rotor Shaft is falling apart, then you can call Richard in WV for a replacement kit [although the kit is NOT inexpensive].
 

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Dummy question but I got the nut off but what appears to be a washer under the nut apparently is not a washer as it will not come off. How is it removed?
Mine had a hard collar of rust between the shaft & the thick washer you're struggling with. I soaked it for days with Power Blaster & tapped it 1000 times with a large brass hammer. Digging in there with a small wire brush & a dental pick helped too.
Don, not sure who painted it red but it sure didn't have any plack paint peeking through anywhere. It was in great shape & I sold it on ebay last year.
 

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Discussion Starter · #12 ·
Thanks to all. I finally had to heat the washer with a torch and wedge it off starting with a thin blade putty knife followed by two cold chisels under the washer to act as wedges. I am sure it never was removed before as the saw blade looks like it was never used. Mine is also red but may have been repainted. The saw is now packed and ready to go with me to Uruguay South America where it will be used with the two Gravelys I have there to cut saplings. The Gravelys have been real work horses on the farm.
 

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Thanks to all. I finally had to heat the washer with a torch and wedge it off starting with a thin blade putty knife followed by two cold chisels under the washer to act as wedges. I am sure it never was removed before as the saw blade looks like it was never used. Mine is also red but may have been repainted. The saw is now packed and ready to go with me to Uruguay South America where it will be used with the two Gravelys I have there to cut saplings. The Gravelys have been real work horses on the farm.
I'm headed to Uruguay on Monday. I'll be working near La Paloma for a couple weeks. I'm installing Wind Turbines on the http://www.nuevomanantial.com/ ranch.
I did find the remains of an L & a reel mower at a wrecking yard near Punta Del Este last month.
 

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I made it back to Uruguay safely but I never heard back from allfoden.
In Miami, TSA sent my crate of tools & equipment on the flight but kept all my clothes etc for further inspection....?
That's always nica after a 36 hour international travel day....
 
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