Snow Going through second stage bolts

[JWR]

Ruffdog: I'll pick your nit just a little: The only way 2 u-joints on the ends of a common shaft can have the same angle is when the two external shafts they connect (e.g. the driving shaft and snowblower input shaft) share a common direction. And, when they share a common direction, the 2 u-joints will automatically be at the same angles. There aren't any other choices. With a snowblower it is a noble goal to keep the two shafts aligned in a common direction; have the tractor / blower combo support that goal. But you also have to have the flexibility to set the blower angle relative to the ground and there will probably be a small difference in the u-joint angles. That's not a significant issue (and besides you have no choice.)

 

[ruffdog]

I have seen people run a tiller or blower NOT level to the ground. They claim it runs better either tilted toward the front or back for some reason. Yes, NORMALLY, the joints are at the same angle running a implement on a 3PH.

 

[jrogers]

Sorry for the delay in getting back to all of you. I am still having the same problem. If anything, it is more based on the amount of time that it runs between failures than the material I am moving. It might run for 45 minutes to an hour before it breaks. I was not aware of this phasing issue, and I am pretty sure mine has a square slip shaft with no key in it. Based on a google search, it seems like there are 2 'OK' positions and two 'bad' positions to choose when putting the shafts together?, right?

Universal Joint operation, U-joint Phasing sketch, Airheads, Paralever Driveshaft, K bikes


I am torquing the shear bold to maybe 10ft lbs. I have varied it a bit, and nothing seems to make a different. Fit in the hole is pretty tight, so I don't think this is the issue.

At this point this phasing thing seems like a reasonable thing to look into. I will post more later.

Thanks!

 

[jrogers]

Look at these two photos which another poster put up on another thread.

There is clearly a design change to solve the breaking of the shear bolts.

The bolt in the new design located where the former shear bolt was is now a solid bolt and the shear bolt is out to the side.
Sure looks like the company was experiencing lots of problems

Dave M7040

Just to clarify, my shear bolt is the bolt that he has labeled as Shear Bolt. Apparently mine came with this mod, since it is all orange.

 

[jrogers]

Also, I am running my blower at PTO Speed (not a slower speed). I do throttle it down when I engage it, but them throttle up before blowing snow. Failure is happening at light load on the motor and not a heavy snow load or when blowing debris.

 

[jrogers]

...But if all else fails, and it keeps shearing that often, it becomes better use of your time to just buy a slip clutch and be done with it.

I don't know what a slip clutch is. Can you explain this further?

 

[PILOON]

If the blower is like shown in post 54, drill out the hole and go next oversize, eg go from 1/4" to 5/16" and use grade 5 or better bolts.
Soft bolts will bend B4 shearing and gall the holes and actually stretch somewhat while graded will shear clean but only on sudden impacts.
Soft shear bolts become a bugger to drive out while graded pop out easily.

Soft bolts will stretch and weaken gradually while graded will only fail on sudden impacts.
The holes want to be sharp as they actually act like a shear.

I learned the hard way having once, in a bind, used a 4" nail instead of a 1/4" bolt, that resulted in galled holes so I reamed out the holes and went next size up and used graded bolts with lock nuts.(not torqued, just snug)
Now I only shear if I digest a stone or some other hard object and the shear bolts are no problem to remove, in fact they simply drop out on their own.

 

[jrogers]

One other thought, make sure the front impellers are opposite on the shaft. If they aren't 180 degrees from each other they may be jamming too much snow in the impeller.

Thanks for the suggestion. I went into the dealer the other day and they said the same thing. I checked, and I do have the right and left augers 180 degrees out of phase so they are not overloading the fan.

 

[jrogers]

If the blower is like shown in post 54, drill out the hole and go next oversize, eg go from 1/4" to 5/16" and use grade 5 or better bolts.
Soft bolts will bend B4 shearing and gall the holes and actually stretch somewhat while graded will shear clean but only on sudden impacts.
Soft shear bolts become a bugger to drive out while graded pop out easily.
I'd start with grade 5.

I am currently using Kubota dealer shear bolts, and I would like to resolve the issue without over-sizing or moving to a different bolt. I am encouraged by others comments that the blower can handle sand and gravel, so I will put some effort into this, looking at the universal alignment as well as the gearbox. I do remove the blower each year by sliding the shaft out and was unaware of the phasing issue, so this is a good place to look.

 

[PILOON]

Oh yes, sand and gravel, so much so that I have no paint on fan, chute or augers after 2 snow storms.
Since fancy paint job is useless I simply spray the shiny paintless surfaces in the spring with a rattle can simply to prevent rust, in fact I don't even color match but even the thinnest paint (rattle can) will prevent rust.
Notice that in winter the metal remains shiny and rust only forms over the hot summer days.
Snow sticks to rust but not shiny metal as well.
For sure the phasing helps as it feeds the fan more evenly.
Buying dealer shear bolts is $$ down the drain IMHO.