Snow Going through second stage bolts

[ruffdog]

That video is REALLY an eye opener. I'm just blown away how ignorant I was of the entire issue. Thanks to you and Dave for speaking up.

Yes, even at the slow speed it is running, it's amazing how much the speed varies on the output end twice every revolution. Can you imagine the torque variations running at full pto speed with a large snowblower impeller on one end? It's tough on the pto clutch, u-joints, splines, shear pins, etc....

 

[JWR]

On my first plow of the year I went through a couple of second stage bolts on my Kubota snowblower. I thought it was from the wet snow, but today we had 6 inches of dry snow, and I went through 3 more. I did not see that I was hitting anything, it seemed like if I even loaded it up much they broke. Any suggestions on how to deal with this, short of putting a non-shear bolt in? Can this be a symptom of something else wrong with the blower? Is it better to torque the shear bolts really tight, or just snug for maximum torque before breaking? Any help is appreciated.

Hey Jrogers ! Take a look at http://www.tractorbynet.com/forums/...owblower-2.html?posted=1&posted=1#post4668190 This guy (using a RAD front mount blower on a Massey about the size of your Kubota) has been breaking pins right and left. Very possibly the same blower adapted to Kubota in your case and Massey in his case. Look at what the guy in post #17 says in that thread. Basically the top sprocket on the side gets loose and begins jerking on the shaft. Eventually it breaks the Woodruff Key on the sprocket shaft but in getting there goes thru a potload of shear pins elsewhere in the drive due to the jerking. Don't think anyone over on this side (in this Kubota thread) has mentioned that possibility.

 

[Jay4200]

On my first plow of the year I went through a couple of second stage bolts on my Kubota snowblower. I thought it was from the wet snow, but today we had 6 inches of dry snow, and I went through 3 more. I did not see that I was hitting anything, it seemed like if I even loaded it up much they broke. Any suggestions on how to deal with this, short of putting a non-shear bolt in? Can this be a symptom of something else wrong with the blower? Is it better to torque the shear bolts really tight, or just snug for maximum torque before breaking? Any help is appreciated.

I've only broken shear bolts a few times in many years of annual use. Once I sucked up a boulder out in the road, but the other times were from cutting the throttle before the blower was completely cleared of snow - whole thing packs up and 'tink' tink' 'tink' - they all break. Perhaps you're not keeping the RPMs up high enough to keep the snow flying inside the blower. Do you run at full WFO when running, 'cause you need to.

 

[ruffdog]

Here is another thread about phasing with very good videos.
Viewing a thread - Drive shaft trainer video.

 

[Dave M7040]

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

 

[JWR]

Yep, Dave is right and I think the dealers and/or RAD as the OEM owe the users a recall and retrofit.

 

[Dave M7040]

Yep, Dave is right and I think the dealers and/or RAD as the OEM owe the users a recall and retrofit.

JWR

I have just sent the following email to Rad.

It will be interesting to see if they will reply to the public.

Perhaps many people should be emailing RAD.

Dave M7040


To: radinter@radinter.com
Your company, who appears to make blowers for various tractor manufacturers, has produced a product being repeatedly talked about on tractor forums for having excessive shear bolt failures under normal operation.

Now we have discovered, quite by accident, that a design change or update appears to have been done.

I have posted pictures of the shear bolt details at the fan hub showing the difference.

Can you advise if this is a product upgrade available to customers who are having to change 5 or 6 shear bolts when blowing snow on their own property with no sign of any obstruction such as a rock which could have caused the failure.

David Petepiece P. Eng.

 

[Jay4200]

Any resolution yet? The shaft phasing thing is interesting - the Kubota front mount blowers have primary drive shafts that just plop apart, unlike the 3pt shafts that run the big boys in the back, so you do have to put the together correctly - can't remember if they have alignment splines or something. You'd think they would if this was a big issue. Now I'm going to have to remember this in case I ever run my BX blower.

 

[aczlan]

Any resolution yet? The shaft phasing thing is interesting - the Kubota front mount blowers have primary drive shafts that just plop apart, unlike the 3pt shafts that run the big boys in the back, so you do have to put the together correctly - can't remember if they have alignment splines or something. You'd think they would if this was a big issue. Now I'm going to have to remember this in case I ever run my BX blower.

Can you look on yours to see if it is square or rectangular? If it is rectangular it will keep the phasing correct.
The mower shaft on our BX2660 is splined but there is a bead of weld between two of the splines so it only goes on one way.

Aaron Z

 

[ruffdog]

Other than phasing, the 2 u-joints should be at the same angles too.