PTO not working for post hole attachment on Yanmar 1500 tractor

[chauke]

So I finally got a chance to use my new post hole digger with my old Yanmar 1500 tractor. I checked that the PTO turned and turned the gearbox and auger after I installed it so I thought I was good to go. However, when I started the first post hole, as soon as it barely made contact with the ground, the auger bit stopped turning. The tractor throttle was all the way high. I tried this in PTO speed 1 and 2, with same results. I would have tried the 3rd speed but I have never been able to get it in speed 3.

Any ideas as to why it does this? Is the PTO shot? I changed out the transmission/hydraulic fluid (with new filter) so the hydraulics should be good!

 

[RustyA]

Most post hole augers have a shear bolt at the top of the shaft to protect u-joints. Is it possible yours sheared off?

 

[cmyoung2]

Also,
Usually PTO posthole diggers operate at near idle speed, not full throttle. Use the slowest speed possible. If the PTO shaft is turning and the auger not, it is a shear bolt. Make sure you replace it with the correct bolt. If not, it may be tractor issues.

 

[oldnslo]

Does the PTO between the tractor and post hole digger stop turning or just the auger bit? If just the bit I would suspect shear bolt like Rusty states.

Does the 1500 have live PTO or does PTO stop when you step on the clutch? If stops when you step on the clutch possible the clutch requires adjustment.

 

[chauke]

Also,
Usually PTO posthole diggers operate at near idle speed, not full throttle. Use the slowest speed possible. If the PTO shaft is turning and the auger not, it is a shear bolt. Make sure you replace it with the correct bolt. If not, it may be tractor issues.

I will try it at lowest speed and look at the PTO shaft to see if it is turning (don't think it was). It was the first time I used it so it had a brand new shear bolt and actually didn't even dig into the ground at all so I think the shear bolt is ok.

 

[chauke]

Does the PTO between the tractor and post hole digger stop turning or just the auger bit? If just the bit I would suspect shear bolt like Rusty states.

Does the 1500 have live PTO or does PTO stop when you step on the clutch? If stops when you step on the clutch possible the clutch requires adjustment.

I think it has a live PTO. When I first tried it, the PTO shaft wasn't turning when I had the tractor in gear. When I put it in neutral, it started turning. The PTO shaft still turned when I let the clutch out, when still in neutral. Is this expected?

 

[bmaverick]

I think it has a live PTO. When I first tried it, the PTO shaft wasn't turning when I had the tractor in gear. When I put it in neutral, it started turning. The PTO shaft still turned when I let the clutch out, when still in neutral. Is this expected?

The YM1500 is a geared tractor, so the PTO is not live. Only the YMxx10 and YMxx20 machines have PowerShift to allow the PTO to be live.

The YM1500 is on the sub-compact frame, s a 3PT PHD has to be a sub-compact to work properly. Full size PHD can often flip small sub-compacts with rocks or other items below the surface soil is hit.

 

[oldnslo]

I think it has a live PTO. When I first tried it, the PTO shaft wasn't turning when I had the tractor in gear. When I put it in neutral, it started turning. The PTO shaft still turned when I let the clutch out, when still in neutral. Is this expected?

With clutch out in neutral the PTO should spin. Was the PTO spinning when the auger bit was not?

 

[chauke]

The YM1500 is a geared tractor, so the PTO is not live. Only the YMxx10 and YMxx20 machines have PowerShift to allow the PTO to be live.

The YM1500 is on the sub-compact frame, s a 3PT PHD has to be a sub-compact to work properly. Full size PHD can often flip small sub-compacts with rocks or other items below the surface soil is hit.

Wow, I was not aware that I had to get attachments for a "sub compact" tractor! I am very tempted to sell tractor anyway. This one doesn't have a front loader and now may have a bad PTO, not to mention all the attachments that I have bought are not for a sub compact tractor. I might try to get a regular tractor if I can find one at a decent price and this time get one that is 4 wheel drive and has a front loader!

 

[5030]

Whatever you get... NEVER OPERATE ANY PHD AT ANY SPEED FASTER THAN AN IDLE.

 

[CobyRupert]

The YM1500 is on the sub-compact frame, s a 3PT PHD has to be a sub-compact to work properly. Full size PHD can often flip small sub-compacts with rocks or other items below the surface soil is hit.

It may be difficult to raise a full size PHD up with a subcompact without he auger digging.

I’ve never heard of a PHD flipping a tractor by hitting something below the surface. Happens often?

If the PTO spins but the auger doesn’t, the place where the spinning PTO shaft meets the non-spinning part is where the (sheer) bolt is missing.

If the PTO shaft from the tractor stops spinning when the auger stops, the problem is likely internal to the tractor. Easiest step is to check any linkage adjustments.

 

[bmaverick]

It may be difficult to raise a full size PHD up with a subcompact without he auger digging.

I’ve never heard of a PHD flipping a tractor by hitting something below the surface. Happens often?

If the PTO spins but the auger doesn’t, the place where the spinning PTO shaft meets the non-spinning part is where the (sheer) bolt is missing.

If the PTO shaft from the tractor stops spinning when the auger stops, the problem is likely internal to the tractor. Easiest step is to check any linkage adjustments.

Many PHDs prior to the 1980s didn't have a shear pin arrangement, When I run mine, it's well below the 540rpms out the PTO due to this ordeal.

Unplanned tractor wheelies are scary as heck!