urgent - sheer bolts on post digger

[jasonp]

hi all,
it's saturday night at 11pm... i'm on a job with my new tractor digging post holes. needs to be finished tomorrow. i did a bit of research, but wanted to get something specific before everyone went to bed!

my digger has been going through grade 2 bolts like crazy today (pto digger on a 50 hp tractor). ground is clay with random big rocks. usually happens getting close to 3ft in the ground. hits something, then snaps the pin. auger manual says to use grade 2... i searched everywhere in town and only was able to find 5 bolts and went through them all!! lowes/home depot has grade 5 bolts.... stupid question... can i use em???
if so, i was going to run out in the morning to get some! if not, i'm screwed!
thanks for any insight.

 

[Johndeere3720]

hi all,
it's saturday night at 11pm... i'm on a job with my new tractor digging post holes. needs to be finished tomorrow. i did a bit of research, but wanted to get something specific before everyone went to bed!

my digger has been going through grade 2 bolts like crazy today (pto digger on a 50 hp tractor). ground is clay with random big rocks. usually happens getting close to 3ft in the ground. hits something, then snaps the pin. auger manual says to use grade 2... i searched everywhere in town and only was able to find 5 bolts and went through them all!! lowes/home depot has grade 5 bolts.... stupid question... can i use em???
if so, i was going to run out in the morning to get some! if not, i'm screwed!
thanks for any insight.

I had the same issue with a PTO tiller on a job. We went through atleast 35 sheer bolts! In your case, I'd get any bolt i could to get the job done. go get all the bolts you can, you'll need them!

 

[E/S]

Use the grade 5 bolts, but slow down the PTO RPM. What RPM are you running at now ? What size holes are you making ? Is it a down pressure post hole digger ?

E/S

 

[teg]

Yes, and slow down the pto... I don't use the phd at 540... more like half that.

 

[jasonp]

i have the rpm running at the lowest speed... i think the idle rpm is 900??
it's a pto attached auger, so there's no real downward pressure (with the pto lowered, the augers rests about ground level).
i'd like to dig 3 1/2 foot holes for my cedar posts (for horse fencing). i've had to go with a few 2 foot holes for the guide posts, but the corner posts should be 3+ feet... and that's usually when i run into sheer problems.

 

[sixdogs]

And "bounce" the digger up and down so it doesn't take such a big bite. Slow down and take it easy and don't make any silly mistakes from being in a hurry. That digger can kill you or rip your arms off.
State in your profile where you are located--or the soil type. Sounds like New England glacial till soil.

 

[jasonp]

i'm actually up in the kingston area of ontario. apparently it's a pretty rocky location i'm digging in. one field is wet, and the ground seems to have lots of 'clay' dirt.

regarding the 'safety'... your statement above freaked me out... if i'm standing by the side of the tractor (by the rear tire) controlling the pto (lift and drive), i should be out of harms way with the auger digging behind the tractor??

 

[beenthere]

Sounds like you are not lifting and cleaning off the auger bit often enough. And also may be letting the weight of the auger and the bite feed it too fast.

Treat it like running an auger bit through wood. Get the diggins off the auger and drop down for more. Shouldn't be breaking that many shear bolts even though it is rocky.
I wouldn't go to heavier bolts, as then something real expensive might break instead. oops:

 

[sixdogs]

i'm actually up in the kingston area of ontario. apparently it's a pretty rocky location i'm digging in. one field is wet, and the ground seems to have lots of 'clay' dirt.

regarding the 'safety'... your statement above freaked me out... if i'm standing by the side of the tractor (by the rear tire) controlling the pto (lift and drive), i should be out of harms way with the auger digging behind the tractor??

That's OK. I have seen many a guy, and I did it a few times as well, rock the frame back and forth while auger was in operation with their sleeves on inches from the spinning PTO. And they were working alone.
No big deal till I saw a workman's comp claim for a guy that was severly mangled in the PTO shaft. Saw another for a woman partially scalped with one. So be careful.
You might need to run the PTP faster and bounce it to clear rubble,

 

[jasonp]

this is how i do it....
- dig a good foot in, lift auger then shake off the dirt
- lower pto/auger all the way and let the weight of the auger help the dig
- lift again when needed and shake off dirt
- lower pto all the way in again and dig as deep as i can
- sometimes lucky, clean hole, othertimes hits rocks, starts jerking and i either stop it in time and shut off pto/lift 3pt or don't stop in time and bye bye sheer bolt

i'm thinking i should't lower the 3pt all the way (i mistakenly stated above 'pto lowered' i meant 3pt hitch lowered)... i lower the 3pt all the way and keep my hand on the pto drive control... shut off as soon as i think necessary.