I'm just about done digging 16 post holes for a new garden fence, and with a perimeter fence replacement in the near future, I intended to find an auger for my tractor soon.

I have an 18hp Yanmar. Erik probably be looking for something around 8". Is there anything I should or shouldn't be looking for as I'm perusing Facebook marketplace and Craigslist?

9" or 12" are the most common auger sizes, assuming you are looking at a typical 3-pt PTO driven unit.
6" also available, if not too small for your posts.

If in central Texas I could give you an option on where to find one. Shipping to Montana wouldn't be cost effective..

milkman00 said:

---

If in central Texas I could give you an option on where to find one. Shipping to Montana wouldn't be cost effective..

---

Depending on whether my brother is coming up this summer or not, that might be an option.

Do you have a Tractor Supply near you? They'll have a 3-point along with 6", 9", and 12" augers.

My only question is will 17hp be enough power? Especially for the bigger augers.

If you are looking at used ones (I bought mine used, smoking deal), you'll need to look at the gearbox and u-joints on the shaft first, then look at the connections on the support arms where the 3 point lift arm connections are welded to the gooseneck. Just make sure that there isn't any rust or obvious really bad areas on these and that the pin connections are in good shape and not wallered or ovaled out, etc. Pretty basic common sense stuff really.

Gear box is where almost all of the stress is, make sure it doesn't have leaks, spins freely and doesn't have slop in it (both input and output shafts), which would be a sign of worn or broken gears. If the u-joints in the shaft are loose, they'll need to be replaced. Make sure the splines on the female spline coupling that connect to your PTO shaft are in decent shape.

Keep a shear pin or two as spares in your tractor toolbox. Sharpen the screw blades.

Post hole augers are pretty simple. First thing I do whenever I buy something that has a gear is to inspect and generally go ahead and change the gearbox oil as I have no idea what is in there, how old it is, how long it has been getting moisture infiltration, etc. Plus I like to know that I've familiarized myself with the piece of equipment so when it inevitably needs work, I'm not going in totally blind.

rather be fishing said:

---

I'm just about done digging 16 post holes for a new garden fence, and with a perimeter fence replacement in the near future, I intended to find an auger for my tractor soon.

I have an 18hp Yanmar. Erik probably be looking for something around 8". Is there anything I should or shouldn't be looking for as I'm perusing Facebook marketplace and Craigslist?

---

What kind of soil do you have? I assume you don't have a bucket? I prefer hydraulic QD versions for their ability to apply down pressure and more importantly reverse the direction of the auger. Once you snag a root or hit red clay and have a lapse of attention, you understand why.

That said, the most cost effective will be PTO 3 point. I have a few and most of them don't get used often. Same with the ones for sale. I have an old one that I got for really cheap. Leaks aren't a huge deal, as you aren't going to use this a whole lot, any gear box driven equipment of mine that starts leaking or making a mess gets a BOX FULL of tractor supply grease. Not oil. Grease. It doesn't leak out as readily and it protects the gears as good. I've run mine for decades like that and they have been used hard in hill country ROCK.

Anyway, there isn't a lot to an auger. Search facebook and CL. If it looks OK, it probably is. My auger has bent fins, and welded teeth where I have field repaired worn out teeth. If you find one like that, it's been used hard and put up wet, so probably look elsewhere.

Jason_InfinityRoofer said:

---

What kind of soil do you have? I assume you don't have a bucket? I prefer hydraulic QD versions for their ability to apply down pressure and more importantly reverse the direction of the auger. Once you snag a root or hit red clay and have a lapse of attention, you understand why.

That said, the most cost effective will be PTO 3 point. I have a few and most of them don't get used often. Same with the ones for sale. I have an old one that I got for really cheap. Leaks aren't a huge deal, as you aren't going to use this a whole lot, any gear box driven equipment of mine that starts leaking or making a mess gets a BOX FULL of tractor supply grease. Not oil. Grease. It doesn't leak out as readily and it protects the gears as good. I've run mine for decades like that and they have been used hard in hill country ROCK.

Anyway, there isn't a lot to an auger. Search facebook and CL. If it looks OK, it probably is. My auger has bent fins, and welded teeth where I have field repaired worn out teeth. If you find one like that, it's been used hard and put up wet, so probably look elsewhere.

---

I live at the base of a mountain in a river valley. It's a lot of slate and other chunk rock, with gravel binder. It's an absolute PITA to dig by hand on the upper section of our place, but gets much sandier as you get closer to the river. You're correct that it probably won't get used a lot. I have ~2500ft of fence that will need to be replaced, and I'll probably do something like a 4-6" post every 10ft with half round cross beams.

As mentioned above, biggest question will be if 18hp is enough to spin it when it hits a football sized rock. We'll see I suppose.

The closest Tractor Supply is ~2 hours away, but there's a couple of tractor places closer by, and a chain store called North 40 which is about like a combination Academy/Tractor Supply. I'm going to shop around if I can't find a cheap used one.

Here is a little bitty compact tractor using one. Granted, soil is way different than yours most likely, but it can be done. They broke a shear pin right off the bat.

rather be fishing said:

---

Jason_InfinityRoofer said:

---

What kind of soil do you have? I assume you don't have a bucket? I prefer hydraulic QD versions for their ability to apply down pressure and more importantly reverse the direction of the auger. Once you snag a root or hit red clay and have a lapse of attention, you understand why.

That said, the most cost effective will be PTO 3 point. I have a few and most of them don't get used often. Same with the ones for sale. I have an old one that I got for really cheap. Leaks aren't a huge deal, as you aren't going to use this a whole lot, any gear box driven equipment of mine that starts leaking or making a mess gets a BOX FULL of tractor supply grease. Not oil. Grease. It doesn't leak out as readily and it protects the gears as good. I've run mine for decades like that and they have been used hard in hill country ROCK.

Anyway, there isn't a lot to an auger. Search facebook and CL. If it looks OK, it probably is. My auger has bent fins, and welded teeth where I have field repaired worn out teeth. If you find one like that, it's been used hard and put up wet, so probably look elsewhere.

---

I live at the base of a mountain in a river valley. It's a lot of slate and other chunk rock, with gravel binder. It's an absolute PITA to dig by hand on the upper section of our place, but gets much sandier as you get closer to the river. You're correct that it probably won't get used a lot. I have ~2500ft of fence that will need to be replaced, and I'll probably do something like a 4-6" post every 10ft with half round cross beams.

As mentioned above, biggest question will be if 18hp is enough to spin it when it hits a football sized rock. We'll see I suppose.

The closest Tractor Supply is ~2 hours away, but there's a couple of tractor places closer by, and a chain store called North 40 which is about like a combination Academy/Tractor Supply. I'm going to shop around if I can't find a cheap used one.

---

I think 18 HP at 540 RPM will spin it OK but it may be taxing it. One of two things if going to happen when you hit a football sized rock. It might sheer a pin, but more than likely it will just sit on the rock stop digging. It will burn your bit up or just do nothing.

I fought this for 100 posts last year in limestone, and each time I swore I was going to buy a rock auger. I never did, and in my nearly solid rock area, you don't need 24" of post depth anyway if you build your fence right, so I did them all with the regular auger.

I would suggest in your case you seriously consider an auger with a ROCK BIT. You are early on in your process to make this worth it, if you can swing the cost which will exceed 1500 bucks most likely. I'm just telling you I broke my back with an auger, post hole digger, san angelo bar, and jack hammer before getting done 6 months later, one hole per day, maybe two if I hit a soft rock. I wish I had just bought the thing early on and been done with it.

What I don't know is that your tractor will have the hydraulic flow to run a bit like this. It might do it but do it really slow, which is still superior to doing it by hand. I don't care if it takes all day to do a hole if I can do it while sitting behind the wheel in stead of on my knees digging by hand.

What kind of fence are we talking about here? Barbed wire?

With the spacing and length of the fence, are you planning on drilling 250 holes? If so, run the auger slow and have lots of shear pins handy.

Are these wood posts or steel? Pressure treated posts are garbage now. Go with steel if you can.

Beltec auger and rock bit is the way to go for rock, anything else is just a waste of time and lots of frustration. Not sure if they make anything for a tractor that small.

I think Treated posts don't hold up because a lot of these fence companies feel like they need concrete in them. I don't know why they do it, but that's what I have seen rot them. I use old telephone poles. The utility company contractors will drop them at my gate or on my property if I ask them. Those are tapered, so you can get posts that are 8", 10", 12" or more sometimes as you move down the pole. These are a pain in the ass to work with since you need a larger auger or hole, and you will need your front end loader to lift and drop them in the hole.

Their sheer size will allow a lot of cheat in the system. You don't need whatever bullcrap hole size/post size ratio, you don't need them nearly as deep if you are in the hill country, they will pull 2000' of 6 strand barbed wire and hold it and they will last until Jesus comes back.

BrazosDog02 said:

---

I think Treated posts don't hold up because a lot of these fence companies feel like they need concrete in them. I don't know why they do it, but that's what I have seen rot them. I use old telephone poles. The utility company contractors will drop them at my gate or on my property if I ask them. Those are tapered, so you can get posts that are 8", 10", 12" or more sometimes as you move down the pole. These are a pain in the ass to work with since you need a larger auger or hole, and you will need your front end loader to lift and drop them in the hole.

Their sheer size will allow a lot of cheat in the system. You don't need whatever bullcrap hole size/post size ratio, you don't need them nearly as deep if you are in the hill country, they will pull 2000' of 6 strand barbed wire and hold it and they will last until Jesus comes back.

---

It isn't the concrete, it's the fact that there isn't any way to wick water away, especially in clay heavy soils. If you put a good gravel bed at the bottom before setting your post and concrete, they will last a good while longer. But nobody is paying for that cost.

I have a bunch of posts that need to be changed out on my fence, but they rotted from the top down, middle out. Next fence I'm going to put post caps on to keep rainwater from being able to get to the heartwood, and probably will put some treatment/sealer/waterseal on top first as well.

The newer chemicals they use for treating wood aren't as effective as the CCA of the old days was, which also doesn't help at all.

Now that you mention it, we used a gravel bed or something of the sort of 'prop' that post off the soil when my buddy and I did his fence on his 5 acre place in CS. We also used a medium sized angular gravel of some kind instead of back fill, and it really locked in the posts. Nice heavy corners, braces, and that gravel made it everything you want it to me.

I own one of those tractor supply brand ones, I forget the exact name, with a 9" auger on it. It works great for digging post holes for 5-7" posts. I run it on my old ford and it is only 23HP with 18-19 or so at the PTO. It goes down well in sand or sandy loam and will work it's way through dry clay if you go a bit at a time but wet thick clay will grab it and stall out the tractor if you aren't careful to lower it in very small increments. You need a helper to set you up and guide the digger to the right marked spot, or it makes work much faster. Setting it up on the tractor also is extremely difficult without 2 people, but it does dig well.

Keep in mind your 3 point might need to be pretty robust to pull it up if you sink it into some clay or wet dirt really deep. A couple of times I have gotten mine buried into wet clay pretty good and had to do some work to unstick it because the 3 point alone couldn't pull it loose. It'll go through small gravel or loose rocks in softer soils but it won't go into dense rock or gravel at all.

If you're not digging a lot of holes, you might try to just borrow or rent one.

I had the cheapest Ag-Meier post hole digger and it worked great. You don't need much HP for these. A few tips:

1.) Don't try to dig post holes in a drought unless you are in sand.
2.) As mentioned above, watch out for getting it stuck in clay soils. You can avoid that by digging a couple inches and pulling it back up.