Help with post hole digger

tractor_time · May 30, 2005

I have an IM 702 with the 9 inch auger and went to use it for the first time yesterday. The pto was spinning the shaft but the auger turned very slowly and stopped completely once it tuched the ground. Any suggestions on what may be wrong.
Thanks, David L3830

Bob_Skurka · May 30, 2005

I would check the "shear pin" to see if it is broken or even missing. It sounds like the auger could be spinning because of friction alone??? There should be a bolt that holds the auger bit in place and a bolt that holds the PTO shaft to auger's gearbox, that bolt is the shear pin. It is there for safety, it is designed to break free if the auger hits something bad (like a huge rock or root) to prevent damage to the gearbox or worse yet to the tractor. That would be the first place I check.

cisco · May 30, 2005

No clue. Do you have a gear box with slip clutch on the auger (only on expensive units), or a shear pin? If shear pin - check, it may not be there. I assume you've securely fixed the 1 or 2 cross bolts that fix the auger to the shaft above it.
You've a rotating shaft going to the gear box from the tractor, and one from the gear box to the auger - what stops rotating when your auger touches the ground, the shaft from the tractor, or the shaft to the auger?

tractor_time · May 30, 2005

The shaft from the tractor to the gearbox continues to spin. The one from the gearbox to the auger stops. I cannot find the book on it to check the shear pin. Where would it be located?

Jimbrown · May 30, 2005

At the top of the auger

JerryG · May 30, 2005

<font color="blue"> Where would it be located? </font>
It will be in the end of the spinning shaft where it attaches to the gear box. Look for a hole that goes through the end of the spinning shaft. That is where the shear pin should be. Most post hole diggers use a grade two bolt. Don't use anything stronger such as a grade 5 or a grade 8, if you do, it will or can damage your pto shaft, gear box or your tractor.

tractor_time · May 30, 2005

It looks like everything is at it should be where the auger attaches to the shaft. If I spin the auger that shaft rotates as well. Its an IM702 model, so maybe it has a slip clutch. Does anyone know where I can find information on IM on the web?

spectre520 · May 31, 2005

Naturally, I can't say definitively but I have seen before that due to lack of oil in the gear box the gears will slowly self destruct themselves and upon usage they will turn under no load but when put under pressure, just slip past each other......Then again, it could just be the shear bolt like everyone elses says.