Posthole Digger Post hole digger basics

[Mosey]

I'm heading to an auction tomorrow and they have a post hole digger with a 12" auger being sold. I know I can buy a new one at TSC for about $460, so I'll use that as a price reference. What do I need to look for when inspecting a post hole digger? I've only seen pictures of them, so I'm not real familiar with them. It looks like you don't use the top link at all, is that right? How do you adjust the angle to make sure you dig the hole straight down? What brands should I avoid? Thanks.

 

[gerard]

1. you're right - no top link, take it right off
2. re angle - gravity will "self plumb" the unit before you start digging as it pivots freely. You'll find however that as the auger decends it won't actually go in vertical due to the pivot point making a gradual arc. After a few holes you figure out that you start the point angled out a little (by using the attached handle) to counteract the natural arc and you can get a pretty vertical hole.
3. re used units - most have shear bolts and you go through a lot of them so as long as the drive unit had oil maintained I don't think there's too much to damage in there. (I bought a TSC unit new because I didn't have a HUGE need for one and so price was a big factor.) Danuser and Bush hog are both good names and generally heavier duty with commensurate higher costs. hydraulic driven units are optimal over PTO because they can be reversed. With a PTO drive you can screw the unit into the ground if you're not careful and then you need to dig it out - not fun or easy!!

 

[MDNick]

Mosey,

The PH digger is quite simple. No, you don't use a top link. Adjusting for a straight hole is really complicated/w3tcompact/icons/grin.gif. By eye or with a level, you trim out the left to right (as referenced off the tractor) by the 3ph lift arm. Front to back is adjusted by backing up or driving forward. You will slightly need to drive forward as it goes down to account for the arc of the digger in the 3ph. Look at the teeth at the end of the auger. There should be replaceable teeth. If not, then they should be in good shape. It makes a heck of a difference. Also, the least amount of sway in your 3ph arms will make a heck of a difference. I really despise my telescoping sway bars for this reason. It is not possible to get all the sway out of them. But less sway will make for a much truer hole.

Look for a PTO shield in good shape that rotates freely, preferably with some stay chain system. It is a LONG shaft, and while you shouldn't be near it during operation, well, sometimes. . . Also look for a lift frame that easily detaches from the auger assembly. All that crap gets heavy for one person to hang on the tractor. Doing the frame first, then bolting the auger assembly to it is MUCH easier.

Down force is a great thing. You probably haven't been looking at a model with that though. Sometimes the auger just won't bight in. I have seen some heads with weight hanging off of them to jury rig down force. WHILE NOT RECOMMENDED, I have leaned on the auger head to get it to go in. That is VERY dangerous, but . . . Sometimes it's what you got, and you can't make a hole any other way.


Can't help you with brands. I have used a Land Pride model, it made a hole, all others have been old/brand unknown.

Nick

 

[Rch]

Mosey, I concur with the comments made above about a snug mounting, dismantlability, PTO shield in place. I have a Worksaver with a 12" and 6'' augers. It has a handle bolted to the gearbox reachable from the tractor seat by turning around so that you can more precisely start the hole perpendicular; the auger doesn't hang straight down, the tip of the auger is further behind the tractor than the gearbox. This handle can easily get bent/busted as it gets caught on tires, fenders, 3 point hitch parts, ROP's etc as the post hole digger sinks into the ground.
Also, on mine the shear pin is between the distal universal joint and the gearbox. There is an extra shield 3/4s around this. Apparently, the shear 'bolt' can be ejected out, projectile like. This is often taken off or not even present on older models ( mine's circa 1991) because in blocks acceess to the shear pin which can get pretty twisted up and difficult to remove. I carry a just the "right size" punch to drive distorted remnants out. I have never actually had a sheared pin "shoot out".
My set-up will go 36" deep. An extension of another 6 to 12 " would be handy.

 

[pennwalk]

Retro fitting older post hole diggers with safty shields can be expensive. If you worry about that kind of thing. You may want to figure that in the price you are willing to pay. Check the Danuser site to see what I mean.

Chris

 

[Mosey]

Thanks for the help. I ended up not buying anything at the auction. The post hole digger was pretty old, no PTO shield, and no teeth left on the auger. I have no idea what brand it was, it might have been homemade. It was freshly painted (could still smell the paint) and it sold for $200. I can get a brand new one at a local farm store for $385 (it’s a "Limbach Line" brand, anybody ever heard of that?). It looks similar to the ones at TSC. This is the second auction I've been to in the last couple years and it's amazing what people will pay for old stuff that they know nothing about as long as it has a new paint job. A homemade boom pole that looked like it weighed $300lbs (it was made out of 4" tube steel) sold for $30. I can get a new one that would be just as strong, but much lighter and easier to take on and off for $60.

 

[RobertN]

One hint before you use the thing... Take out the shear bolt, check it for size. Then, go to the hardware store and get a bag of bolts and nuts. then reinstall the shear bolt.

It'll be easier to find a new shear bolt if you have the old one in one piece. Once it breaks, at least part of it will disappear...

Keep the shear bolts and a wrench handy...

 

[Mosey]

Robert, That sounds like good advice! I wonder if it would do any good to wrap the shear bolt with duct tape to keep it from flying off and hitting someone or something?

 

[RobertN]

The auger doesn't really move very fast. The pieces of shear bolt just seem to fall in the loose dirt and get sucked up by some supernatural magnetic force of the universe /w3tcompact/icons/grin.gif

 

[reslaire]

Also, note the grade of the bolt and buy the right grade. As I remember it, they are grade 3. You want bolts that will shear relatively easily (not TOO easily, mind you but just right!).

Bob.