Grading 390 front blade on John deere 1070 4x4

[beagleboy]

I have a chance to buy a 390 front blade for my 1070 4x4 and I was wondering if they are made strong enough to push more than snow,such as dirt and gravel or if they're pretty limited to snow. I have a back blade now but thought the hydraulic angling would be nice. I see they don't really offer these front blades for the new compacts so evidently they didn't sell very good or wasn't very strong. Could someone out there tell me what they know about these front blades?

 

[kennyd]

I have a 380 that I modified to fit my 4110, they are definitely built heavy duty! Not a dozer, but certainly up to the task of moving loose dirt and gravel. They even include bolts to "lock out" the trip springs. Look in the Picassa link in my sig for the "plow pics" folder.

They still offer these for the mid-sized compacts like the 4x00, 4x10, and 3x20 series machines. They just go buy a new number like the "74" and the "366" blades. pretty much the same except for the mountings.

 

[JD755]

The 380 and 390 are very heavy duty. But I never use mine anymore because to install it on the 55 series requires removing every bracket from the tractor that is used for the 70 loader. Even the long loader bar through the frame. You then install a different set of brackets for the 380 blade. After doing that back and forth a few times I decided it was not worth it. I now just use the loader and box blade for dirt work and a rear three point blade for snow.

Having said that, the 390 has the big advantage of using a quick attach set up instead of what the 380 requires. So I say if the price is right then go for it. I always enjoyed using mine when it was installed and is a lot easier than watching a fixed blade over your shoulder. I did a lot of dirt work with it and it was always up to the job.

I would still try to clarify any issues with the loader brackets because even with quick hitch there may still be some.

 

[Barely Smokin']

x2 with JD755. I've got the same plow. I hook it up about once a year in anticipation of the "big snow". It's usually a waste of my time, primarily b/c it's so much friggin' work to unbolt the FEL brackets and bolt on the plow brackets. **** shame JD didn't make the mount fungible between the two. It's worked well in the snow the few times I've used it in the snow.

I've never used it to push dirt, gravel, etc. I suppose it would work decently well. In fact, just the other day I saw a 790 with a front blade on a construction site being used to push gravel into the excavation for a sidewalk. I think they main advantage there was small size and weight of the 790 for that application.

At the same time, I'd be cautious about using the blade for moving anything other than loose material. The blade construction is reasonably tough, but there's a lot of torque being exerted on the pivot and hydraulics, not to mention the mount. This is especially so when you load up the tip of the blade---the whole system flexes. With regular use in an earthmoving application, where you're likely to be hitting immovable roots and rocks, I think the blade set-up would get over-worked. Compare this to the geomtery of a rear blade, where the span of the TPH arms is much wider and better suited to handling those angular loads.

 

[Deleted member 216442]

I have a chance to buy a 390 front blade for my 1070 4x4 and I was wondering if they are made strong enough to push more than snow,such as dirt and gravel or if they're pretty limited to snow. I have a back blade now but thought the hydraulic angling would be nice. I see they don't really offer these front blades for the new compacts so evidently they didn't sell very good or wasn't very strong. Could someone out there tell me what they know about these front blades?

I see this is an old thread, but maybe you bought it and have the hassle of bracketry changes between FEL and 390 blade. I had the same hassle with my 1070, 440 FEL, and 390 blade. I then modified the rear 390 brackets so that they mimicked the FEL brackets by welding on square tubing and little ears to locate the FEL. Now I can switch back and forth between the FEL and 390 blade in a few minutes in winter. It isn't that much work or welding to fabricate - the hardest thing was making a pattern to get the square steel tubing in the right place on the bracket at the right angle - I made a heavy paper pattern for that and it worked fine. In summer I use it for mowing so I remove the modified 390 brackets and go back to the originals that can be used to install the mower hangar stuff. Once a season is not too much a hassle.

 

[kennyd]

I see this is an old thread, but maybe you bought it and have the hassle of bracketry changes between FEL and 390 blade. I had the same hassle with my 1070, 440 FEL, and 390 blade. I then modified the rear 390 brackets so that they mimicked the FEL brackets by welding on square tubing and little ears to locate the FEL. Now I can switch back and forth between the FEL and 390 blade in a few minutes in winter. It isn't that much work or welding to fabricate - the hardest thing was making a pattern to get the square steel tubing in the right place on the bracket at the right angle - I made a heavy paper pattern for that and it worked fine. In summer I use it for mowing so I remove the modified 390 brackets and go back to the originals that can be used to install the mower hangar stuff. Once a season is not too much a hassle.

Sounds like a great mod, got pics?

 

[Deleted member 216442]

Here are some pictures of my 1070 with 390 blade sporting the modified rear brackets that I made so I can switch to the 440 loader quickly. I added the square tubes to the rear brackets. Also shown is my blade height extension which prevents me from squeezing the unit in the garage so it stays off till I need it.