How Much PTO HP is needed for an 18" Auger?

[Joe1]

Will a John Dere 770with about 20 - 21 PTO HP be able to handle an 18" auger, particularly in heavy clay soil? I have not used an auger with this tractor before and do not want to break anything on the tractor.

Seriously, thank you in advance to all your hands on experts.

 

[Menagerie-Manor]

If you research 3 point Auger sizes and capabilities they generally include HP requirements, 18" is gonna be pushing the envelope.

 

[rScotty]

Will a John Dere 770with about 20 - 21 PTO HP be able to handle an 18" auger, particularly in heavy clay soil? I have not used an auger with this tractor before and do not want to break anything on the tractor.

Seriously, thank you in advance to all your hands on experts.

Why an 18" hole?

The hp required for a post hole drill varies a lot on the way the auger is built. Soil is so completely different everywhere that all a person can do is relate their own experience.
In clay, a lot depends on moisture and advancing the depth very slowly....sometimes with water.

Unfortunately, an inexpensive auger with large pitch, a simple screw tip, and a single cutting edge won't do much in heavy clay soil regardless of auger size. And an 18" would require a really big heavy tractor and probably in heavy clay a category II 3pt. And even so, that's not the way I'd go.

If you use an better auger with a fine pitch and dual cutting edges with bolt-on carbide teeth - a fairly expensive auger - then your 770 should be able to handle a 9 to 10 inch size in heavy clay if everything is right and you can advance it slow enough....maybe with some water. Not sure about an 18" on a little tractor in any soil. That's pushing things.....

Give it a try and let us know.

rScotty

 

[Tinhack]

An 18" auger in heavy clay soil will most likely require 80-120 Hp. If you're digging footers, I'd just farm it out to someone with the equipment. They usually have a large truck like a drilling rig.

 

[rScotty]

An 18" auger in heavy clay soil will most likely require 80-120 Hp. If you're digging footers, I'd just farm it out to someone with the equipment. They usually have a large truck like a drilling rig.

I agree. You said the same thing as i did, but much more economically.
BTW, we hired a drill rig to do holes for our pole barn. Best decision we could have made.
They not only punched the holes in the right place, they set the poles.

 

[M59]

Will a John Dere 770with about 20 - 21 PTO HP be able to handle an 18" auger, particularly in heavy clay soil? I have not used an auger with this tractor before and do not want to break anything on the tractor.

Seriously, thank you in advance to all your hands on experts.

Joe1,
First impression. a big NO.
What your not stating is type of auger. Hydraulic or 3 pt?
Second impression. There is no way at 21 pto hp that your going to move clay on a 18 inch dia hole regardless of auger drive type.

My auger preference is hydraulic mounted on FEL via SSQA so you can easily see what you are doing and can apply massive amounts of down pressure and reversing auger when it binds up or needs flutes cleared. Wet clay cuts easier but is very gummy and clogs flutes quickly so auger either needs to come up out of hole frequently OR you need lots of hp to hydraulically deliver the needed torque and dry clay is like drilling cement.

My 2 cents running a SSQA hydraulic auger on 59 hp M59 TLB and augers up to shrub prep auger of 30 inch dia.

 

[Rockbadchild]

I have solid clay soil and made many holes, I don't see why you couldn't, I dig my holes at a very low RPM to me HP is not a factor and I don't see why it would be. If its wet you need to lift it every so often if not the bit get suck there then you are in a pickle, you need to disconnect the PTO shaft and get a pipe wrench and turn it the opposite direction or hand shovel it out. If its dry it is very slow and I needed to apply weight to it for it to go down, the clay came out in small chips just chewing at it. More HP doesn't apply more weight, the only thing Hp will do is make your tractor heavier so yo have more lift capacity to lift the auger full of dirt ... lots of folk do their holes with a two man auger not many HP there, it’s a nasty job but people do it.

To me the worse thing that can happen is you will stall the tractor but just go slow.

 

[old and tired]

....if not the bit get suck there then you are in a pickle, you need to disconnect the PTO shaft and get a pipe wrench and turn it the opposite direction....

I did this, you don't have to unhook the PTO shaft. Turn off the tractor, I had bought a 36" pipe wrench (just in case this happened) and unscrewed the bit.

Go slow is key, and have your foot on the clutch to be press quickly!!!

 

[Bavarian]

Pto auger don't need much HP.
As mentioned, weight or down pressure might be the deciding factors next to unexpected obstacles like rocks in the ground.

 

[akadave]

I'm going with nope.

 

[LD1]

IT will be fine.

You wont be able to help but to go slow. No down pressure.

But the HP is fine. The people saying it isnt must not have drilled many holes

 

[Rockbadchild]

IT will be fine.

You wont be able to help but to go slow. No down pressure.

But the HP is fine. The people saying it isnt must not have drilled many holes

But unless you have down pressure assist more HP doesn't affect the down pressure... I my missing something ?

 

[Fxfymn413]

I use an 18" auger bit quite frequently to dig holes for shrubs and footers for deck posts using my 4060 in all types of soil including the commonly found red clay in our area. As others have said digging is not taxing on the machine, but clay tends to pull the auger into the ground pretty quickly and it does become "stuck" in the sense that it cannot be lifted. My solution is to go slow and lift the auger frequently with the PTO off until it clears the hole. Turn the PTO back on to clear the auger of dirt and repeat.

I have used my BX 2660 to power the auger on occasion, usually with a 9" bit for fence posts, but I recently used it with the 18" bit to dig a footer because the large tractor would not fit where I needed to go. Frankly I was surprised at how well the tractor handled it and I would not be concerned about doing it again. The soil was a mix of gravel and clay.

I use a Danhauser auger with no down pressure cylinder.

 

[qualsite]

With our heavy clay soil that you can't drive a metal stake into in the summer, I found that my 10" auger does nothing but spin on the surface. You have to have the area just damp enough that the ground will even allow an auger to work and not become an agitated mud pot. Same with my ditcher. I use a drip line, then let it soak in and dry out enough to be able to do anything with it. I also found that I had to modify the leading cutting edge of the auger to better dig into this nasty ground. Even then, I have a big weight on the auger. My 28hp works fine with the 10" with the above caveats, but you may be pushing it with as big a hole as you're trying in dense ground. And yes, with the clay soil, pull it up VERY often to clear the hole, otherwise it will get stuck.

 

[ernieatv]

Why an 18" hole?

The hp required for a post hole drill varies a lot on the way the auger is built. Soil is so completely different everywhere that all a person can do is relate their own experience.
In clay, a lot depends on moisture and advancing the depth very slowly....sometimes with water.

Unfortunately, an inexpensive auger with large pitch, a simple screw tip, and a single cutting edge won't do much in heavy clay soil regardless of auger size. And an 18" would require a really big heavy tractor and probably in heavy clay a category II 3pt. And even so, that's not the way I'd go.

If you use an better auger with a fine pitch and dual cutting edges with bolt-on carbide teeth - a fairly expensive auger - then your 770 should be able to handle a 9 to 10 inch size in heavy clay if everything is right and you can advance it slow enough....maybe with some water. Not sure about an 18" on a little tractor in any soil. That's pushing things.....

Give it a try and let us know.

rScotty

An 18" auger, don't think it's a good idea on a small tractor like yours unless you start with a smaller auger. I would start with a 8" or 9" auger and then you'll see how hard the clay is. Then the 18"

 

[sd455dan]

Think it will work, the thing I would be concerned with is auger speed and possibly stalling the smaller engine. Usually like to keep the speed way down which means idling the tractors engine. I did a lot of 2' holes with the Ford 3000 and the only problem was occasionally hooking into a strong root. This was using an industrial heavy skid steer bit adopted to fit the Leinbach 3 point PHD

Can't speak for anyone else But, I would definitely try it.

 

[4570Man]

IT will be fine.

You wont be able to help but to go slow. No down pressure.

But the HP is fine. The people saying it isnt must not have drilled many holes

I’ve only used an auger one time that I rented for my skid steer and it made easy work of drilling holes. I don’t know what kind of power the auger motor put out but it can’t be a lot with just standard flow hydraulics. I’m honestly surprised at the number of people saying it won’t work. It very possibly won’t work because the small tractors 3 point hitch isn’t big enough but power wise it would be fine.

 

[sd455dan]

An 18" auger, don't think it's a good idea on a small tractor like yours unless you start with a smaller auger. I would start with a 8" or 9" auger and then you'll see how hard the clay is. Then the 18"

edit:

After re reading your response, I see what you were suggesting was to test the soil toughness with a smaller diameter auger to see how the engine handles it, not pre-drill the holes and then step up the diameter.

 

[4570Man]

An 18" auger in heavy clay soil will most likely require 80-120 Hp. If you're digging footers, I'd just farm it out to someone with the equipment. They usually have a large truck like a drilling rig.

That’s just completely wrong. An 18” hole is pretty easy work and people do it with mini skid augers every day. I doubt you could even find a 18” auger and gear box rated for 120 hp.

 

[4570Man]

An 18" auger, don't think it's a good idea on a small tractor like yours unless you start with a smaller auger. I would start with a 8" or 9" auger and then you'll see how hard the clay is. Then the 18"

I don’t have much experience auguring holes but I think it’s better to go for the desired hole the first time. I think the bigger auger would corkscrew itself into the smaller hole without much resistance to slow it down.