Grading John Deere 84 Front Blade on a 4720

[TCowner]

I am looking at a used 7' #84 front blade that is supposed to fit the 4500-4700 and Ten series tractors. Deere doesn't list the 84 blade for the 4000 Twenty tractors on their site.

Any thoughts on what it would take to modify the attaching pieces so that it would fit my soon to arrive 4720.

 

[dirtworksequip]

TCowner, you will need to take measurements off the 4500-4700 series tractors to see if the mounting holes are anywhere close to your 4520. I mounted a JD 390 front blade on my 3520 by using a model 74 frame. You may be able to do the same. The 74 isn't listed to fit the 3520,but my frame holes where the same as an older model 4XXX model tractor.
The front blades do make for a nice set up and I prefer them over the loader mounted blades. I also modified my loader mounts so I can switch between the 300cx loader and the 390 front blade without removing any of the mounts.
Making your tractor compatible with the model 84 blade would be well worth the effort.
Sincerely, Dirt

The below pic is of the rear blade mounted behind the loader/cab mount.

 

[TCowner]

Thanks for the reply and the pictures. How exactly did you modify your loader mounting bracket?

Terry,

 

[dirtworksequip]

Terry, a friend of mine has a fabrication shop and he cut the width of the front blade bracket out of the loader bracket and rewelded the loader bracket. That enables the blade bracket to bolt behind the loader bracket and still maintain the same length loader bracket. It was a little more complicated on the cab tractor as the loader bracket is also the front cab mounts. So I had to unbolt the cab mounts, jack up the cab and remove the loader/cab mounts. Then have him modify the bracket and reinstall them on the tractor. It's not so complicated on the open station tractors as you just have to remove the loader mount and cut/reweld to the proper length. Some others on the forum have suggested just mounting the blade brackets behind the loader brackets without removing the 1/2 inch and just let the loader towers take up the 1/2 difference. I'm not sure if this will work or not as I have never tried it.
If you look real close in the pic of the loader bracket you can see the weld on the black part of the loader tube. That's where he took out the 1/2 inch to make up for the blade bracket being mounted behind the loader bracket.
The only drawback of this set up is you can't use a mid mount mower,because its not compatible with the blade brackets. That's not a problem with me as I would prefer a 3pt RFM.
Any competent weld shop would be able to modifiy your loader bracket and you would be in business as long as the blade mounts will line up with your mounting holes on your tractor. I actually ended up using the rear part of a model 74 and the moldboard and hydraulic cylinders off my old 390 front blade because I liked the wider blade on the 390 over the model 74.
If you have any questions feel free to email me at dirtworksequip@aol.com or PM me here. I'd be glad to take any pics you need or give more advice if you need help.
Sincerely, Dirt

 

[TCowner]

Dirt, thanks again. My 4720 on order is a factory cab as well. I will email you for some more pictures.

Terry

 

[KB9UDE]

I had a 4500 with 460 loader and 84 front blade at one time. I did the same mounting as dirt but did NOT cut anything off the mounts for the loader. All I did was use longer bolts with the loader mount on the outside of the blade mount. I don't know if this will work with the 300cx\400cx series loader mount but it worked fine on the 460 loader.


John

 

[dirtworksequip]

I got to thinking about just putting the blade brackets behind the loader brackets................it won't work on a cab tractor as the loader bracket has the front cab mount made onto it. If you mount the blade brackets behind the loader brackets on a cab tractor the holes will not line up correctly for the cab mounts unless you cut and reweld 1/2 inch out of each loader mount tube.
Sincerely, Dirt

 

[jcalla]

Hi, I am new to this forum. I have purchased a used front blade #84 3680M 7' wide. I would like to mount it on a new 2010 John Deere 4720 (with cab) that I have ordered. I know this is an old post but maybe someone will walk me through the steps I need to do to make this fit. Pictures would be helpful.

John Callaway

 

[kennyd]

Hi, I am new to this forum. I have purchased a used front blade #84 3680M 7' wide. I would like to mount it on a new 2010 John Deere 4720 (with cab) that I have ordered. I know this is an old post but maybe someone will walk me through the steps I need to do to make this fit. Pictures would be helpful.

John Callaway

Welcome to TBN

Do you know what machine it was removed from? Do you have all of the mounts?

 

[beenthere]

Wondering if TCowner ever put his #84 blade on his JD 4720, and has some pics.
Maybe he will chime in here.

Is it similar to the 390 that Dirt shows mounted on his tractor?