3520 and Post Hole Diggers

317140 · Aug 6, 2006

I am getting ready to fence in some of my property for a cow or two. I have never used a PTO post hole digger. My brother got one on a package deal for a gray market tractor that he bought. He was too cheap for a John Deere. I cant bad mouth him much because I want to use his digger. I was wondering if anyone could give me some advise on operating this auger. The PTO on my 3520 starts immediately and doesnt have any provision to feather it in or to start it slow. I know some of You have used one and can help me out. On my brothers tractor he just feathers the clutch and works the foot throttle and it seems to work well. I dont have those options so I need Help.

radman1 · Aug 6, 2006

I assume it is a 3 pt PHD. Post hole digging 101 class. Find the spot where you want the hole and just lower the pointed tip of the auger into the ground but don't put all the weight of the PHD on the tip. Position the tractor as needed to get the bit vertical (forward, back, side to side etc). The tip in the ground should hold in in place. Start your PTO, in your case don't worry about starting it slow. Continue to lower the 3 pt. as the auger digs. If it doesn't dig, keep lowering the 3 pt for more weight. I always run my tractor at idle. You will have plenty of power with that size of tractor. If you hit something much better to kill tractor than break PHD. Besure the Pto shaft has shear bolts (lighter grade bolt). Have a few extra bolts on hand in case you hit a root, rock etc.
As you dig, you may need to slightly change the position of the tractor, forward or backward, to keep the hole straight. As the 3pt lowers, the PHD digs in an arc and moving the tractor will give you a straight hole.
If the ground is real hard, I did mount an angle iron bracket on the PHD gear box and added front end weights (100-250 lbs). It is nice to have a pipe wrench handy if the bit gets stuck on something. Use the pipe wrench to turn the auger bit backwards to remove.

dirtworksequip · Aug 6, 2006

If you are augering thru grass, keep the serrated cutting edge free of grass. Only a litte bit of grass on this edge will keep it from augering the hole. Be sure to kick out your PTO when you are repossitioning to plumb up for a straight hole.

radman1 · Aug 6, 2006

Good post about grass or tree roots on the cutting edge. A little bit will stop it from digging. You can either put the PHD down, start digging, raise and clean the grass off the cutting edge or use a spade or shovel and clear the grass away before starting the hole. Sometimes using the spade to remove the grass on all the holes to be dug is the first step. This will mark the location for all the holes and then go back and use the PHD.

anojones · Aug 7, 2006

The PHD doesn't need to be run at 540 PTO speeds, I run mine between idle and 2000 rpms. Another thing to watch for is getting the auger stuck, if you dig all the way to the gear box in one go the auger can get stuck as there is no reverse- so make sure you dig part way, pull it out and start re-digging until you figure out if your ground is soft enough to dig all the way in one go.

Kyle_in_Tex · Aug 7, 2006

One more thing, a PHD can "screw" itself into the ground so it can help to keep your front bucket full of dirt for counterbalance weight.

Keep RPM's low as stated before.

SteveH_CT · Aug 7, 2006

I think everyone said it one way or another, but let me spell it out for you too, when you start the PTO have your engine speed slow, I do mine around 1400 or 1500 RPM, as the auger digs down I crank the speed up gradually getting to 2400 RPM (give or take a bit depending on the hole).

I just have finished about 150 holes, and man is the PHD a life saver. Keep several shear bolts handy if you have rocky or rooty soil (big roots, little stuff won't bother it), and if it has replaceable cutting edges plan on getting an extra set or two of those as well. I went through 3 sets myself. When the edges get rounded off, the auger loses a lot of it's bite, and as a result will not be able to get many holes completed.

So much depends on your soil - We have nasty rocky stuff here in my area - if you have generally "clean" soil, then it will be a breeze - if it's rocky (cantelope size and up) you should have something available to help you pop them out of the way of the auger - I used a 5' steel rod.

Good Luck with it!

317140 · Aug 8, 2006

I really appreciate the good advise. The land around here is very rocky and hard because it is so dry. I will probably wait until the weather cools down a bit and we get some rain. I have to wait for the surveyors to mark some property lines for me so I get my fences on the line. I have a fair amount of trees to cut and I need to clear some brush and undergrowth before I dig post holes. Hopefully the weather will cool down soon and I can get started. Seems like we only get enough rain to keep the grass growing and the weeds.

radman1 · Aug 8, 2006

Rocks! Definitely dig slowly. Fortunately for me, I live in a area of very few rocks. Mostly just black dirt and clay. If I hit a rock, everyone gathers around and stares at it. "Wonder how that got there?"

rockyridgefarm · Aug 10, 2006

I have used a post digger and found that all of the advice so far is great. I also have very rocky soil, and only have one other suggestion:

Don't use a post hole digger.

I almost always prefer to drive my posts. After fighting all the rocks and trying to get a straight hole with the digger, you end up with a hole to set your post in and then have to hold it straight while you tamp and concrete the post in place. After driving a post, it is even stronger, with no tamping or concrete.

YMMV.