Questions about John Deere 790

[pretendfarmer]

I just purchased a beautiful JD 790 4x4. The tractor only has about 400 hours and came with a loader but no other attachments. I first want a back blade as I am going to be grading driveways. I was just assuming I should buy a 5' size since it is just wider than the rear wheels. But would 6' be better since this is in fact a 30hp tractor? I think my little 20 horse Yanmar had a 5' blade.

I'm looking for recommendations on rear blades and box scrapers. It seems inventory is kind of thin right now. The high quality, heavy rear blades seem to be out of stock in my area. Apparently Land Pride is 9 months out or something, according to the dealer.

 

[beenthere]

Congrats on the 790. Think 6' blade should work well for you. Good luck finding a used one in your area.

 

[loggin]

I just purchased a beautiful JD 790 4x4. The tractor only has about 400 hours and came with a loader but no other attachments. I first want a back blade as I am going to be grading driveways. I was just assuming I should buy a 5' size since it is just wider than the rear wheels. But would 6' be better since this is in fact a 30hp tractor? I think my little 20 horse Yanmar had a 5' blade.

I'm looking for recommendations on rear blades and box scrapers. It seems inventory is kind of thin right now. The high quality, heavy rear blades seem to be out of stock in my area. Apparently Land Pride is 9 months out or something, according to the dealer.

I would go with the 6 foot blade. There are likely more of them to find used and they tend to be a little heavier which helps to dig into the material. Your tractor should be plenty powerful to use it especially in lower gears.

As far as the box blade goes might be better to stick with a 5 footer. Box blades can become quite a load especially when you engage the ripper teeth and have some material built up.

Just my 2 cents.

 

[RoyJackson]

Having owned a 790 several years ago, I think the 5' blade would work better...depending on how much grading (and type of material) you want to grade. Tire type will count as well. Real light loose dirt, the 6' blade would likely work. Hard packed soil or gravel could be a bit much
The 790 is a pretty light tractor, weighing in a bit over a ton (not including the loader), and that may be the deciding factor.

 

[erikjohn67]

I have a 790 and a 5’ and 6’ box blade. It handles either one fine. The 6’ one is quite a bit beefier than the 5’ one. I will use the smaller one for fine grading but the larger one for tearing up the road to regrade it. FWIW My tractor has turf tires on it.

 

[pretendfarmer]

Something else I've been thinking about - the ROPS is about 4" too tall to fit into my enclosed trailer. I had to remove the top bar and let all the air out of the tires to clear the door. I'm thinking of cutting the steel and then installing a heavy sleeve inside where I can remove half of it for clearance purposes, then reinstall after moving it. It doesn't seem like this would interfere with the structural integrity at all. Any thoughts?

 

[jyoutz]

Something else I've been thinking about - the ROPS is about 4" too tall to fit into my enclosed trailer. I had to remove the top bar and let all the air out of the tires to clear the door. I'm thinking of cutting the steel and then installing a heavy sleeve inside where I can remove half of it for clearance purposes, then reinstall after moving it. It doesn't seem like this would interfere with the structural integrity at all. Any thoughts?

Cutting and messing with the ROPs is typically considered a big no-no that jeopardizes the integrity and safety of the ROPs. Some people do this but it’s never recommended.

 

[pretendfarmer]

Cutting and messing with the ROPs is typically considered a big no-no that jeopardizes the integrity and safety of the ROPs. Some people do this but it’s never recommended.

I understand that, and I don't want to do any modifications which would undermine the integrity. But it's all just steel, so no special sauce. The newer ones have folding ROPS. If they're strong enough, this would be plenty strong enough.

Another idea is to grab an extra set of smaller tires and wheels to throw on the rear when I'm ready to haul it. Then I wouldn't have to air down the tires and remove the top bar. I'm just trying to figure an easier way of getting this into my enclosed trailer.

 

[beenthere]

Something else I've been thinking about - the ROPS is about 4" too tall to fit into my enclosed trailer. I had to remove the top bar and let all the air out of the tires to clear the door. I'm thinking of cutting the steel and then installing a heavy sleeve inside where I can remove half of it for clearance purposes, then reinstall after moving it. It doesn't seem like this would interfere with the structural integrity at all. Any thoughts?

I would cut it down to fit. Might be a no-no to some, but it is your tractor and your convenience to consider here.

 

[Reddogs]

I just purchased a beautiful JD 790 4x4. The tractor only has about 400 hours and came with a loader but no other attachments. I first want a back blade as I am going to be grading driveways. I was just assuming I should buy a 5' size since it is just wider than the rear wheels. But would 6' be better since this is in fact a 30hp tractor? I think my little 20 horse Yanmar had a 5' blade.

I'm looking for recommendations on rear blades and box scrapers. It seems inventory is kind of thin right now. The high quality, heavy rear blades seem to be out of stock in my area. Apparently Land Pride is 9 months out or something, according to the dealer.

NO...., under no circumstances get a 6 foot on the 790. I made that mistake and it scraped both sides of my tires for the past 20 years when I turn..... If you want to try it come by and take mine and you will see...

 

[jyoutz]

NO...., under no circumstances get a 6 foot on the 790. I made that mistake and it scraped both sides of my tires for the past 20 years when I turn..... If you want to try it come by and take mine and you will see...

How does a blade scrape both sides of your tires? Makes no sense. And the moldboard is a long ways from the tires. What difference would it make if it was 5 or 6 feet?

 

[RoyJackson]

How does a blade scrape both sides of your tires? Makes no sense. And the moldboard is a long ways from the tires. What difference would it make if it was 5 or 6 feet?

If you have it angled...

 

[jyoutz]

If you have it angled...

Would have to be angled sharper than most folks would ever use it. And that depends on the blade design more than the width. I have an 8’ blade that can be spun 360 degrees and the frame holds it well back from the wheels. I would look for a blade with 360 rotation capability.

 

[Reddogs]

How does a blade scrape both sides of your tires? Makes no sense. And the moldboard is a long ways from the tires. What difference would it make if it was 5 or 6 feet?

Tractor tires are not smooth, so they scrape....and the 6 is inches away, so try to turn and see what happens...

 

[Reddogs]

If you have it angled...

Exactly...

 

[Reddogs]

Would have to be angled sharper than most folks would ever use it. And that depends on the blade design more than the width. I have an 8’ blade that can be spun 360 degrees and the frame holds it well back from the wheels. I would look for a blade with 360 rotation capability.

I've tightened mine to the max and it still swings as the 6 is too much for that size tractor, go figure..

 

[RoyJackson]

Would have to be angled sharper than most folks would ever use it. And that depends on the blade design more than the width. I have an 8’ blade that can be spun 360 degrees and the frame holds it well back from the wheels. I would look for a blade with 360 rotation capability.

The 790 is a considerably smaller tractor than your Kubota...and, even with sway links (chains on the 790), an implement can sway quite a bit.

 

[beenthere]

Reddogs: Show us a pic of the connected 6' rear blade on your 790.

Suspect the sway chains not connected right or the tires set too far out. Might just need some extensions either on the arms or on the blade frame for the 790 (Yanmar tractor I believe).

A 6' rear blade used at an angle will cover the tracks and the end reach out to be able to blade a ditch out. 5' blade, not very possible.

Have had a 6' blade for 50 years and sometimes for grading ditches, wish it were 7'. Originally on my '58 JD 420 2-cyl

 

[Reddogs]

Reddogs: Show us a pic of the connected 6' rear blade on your 790.

Suspect the sway chains not connected right or the tires set too far out. Might just need some extensions either on the arms or on the blade frame for the 790 (Yanmar tractor I believe).

A 6' rear blade used at an angle will cover the tracks and the end reach out to be able to blade a ditch out. 5' blade, not very possible.

Have had a 6' blade for 50 years and sometimes for grading ditches, wish it were 7'. Originally on my '58 JD 420 2-cyl

Its similar to this cutter on a 790 as I dont have it attached since it gave me so much grief...

https://www.equipmentfacts.com/listings/farm-equipment/auction-results/203196701/john-deere-790

See in the 6th photo, how close the lower links are to the tires, that is what hits against them when you turn on the 6 foot cutter. which isnt helped by the sway chain links as its too much for it to hold tight..

 

[jyoutz]

I think it’s the implement design, not the width that’s the problem. When I shopped for my 8’ blade I wanted one that was designed to be rotated 360 degrees without touching the tires. Some brands couldn’t do this, while some were built for 360 rotation. It’s how long the mounting beam extends from the 3ph. The cheaper brands and models couldn’t be rotated 360 degrees.