Snow Going through second stage bolts

[jrogers]

I switched to a roll pin in the U joint and went out to do the driveway. Went through 2 more shear bolts in the second stage. They really sand out road heavily, and I am back to thinking that the problem is the sand, or probably more accurately, the gravel that they are using. It seems like it is similar diameter to the gap between my fan blades and the housing. Any ideas as to how to best tighten up this gap? Here is one I found:

SNOW BLOWER IMPELLER KIT™ - 1/4" 4-Blade Universal - Modifies 2-Stage Machine | eBay

But it looks a bit light weight for my application. Another idea that I was considering is removing the fan blades and welding on the end and grinding to narrow up the gap. I am not sure how much work it is to get the fan blades out. If anyone has experience with this I would be interested in hearing of there is an easy way to get the fan out, but it looks like it would be a pretty major disassembly. Also, if there are any products that I can slip on the ends of the fan blades to decrease the gap, but this may be hard to keep in place.

 

[Dave M7040]

Consider going to Salem Power and compare the parts and upgrade kits they have for Bercomatic blowers. I think same origins as RAD.

Salem Power Equipment, LLC - Search Results for "16517"

The upgrade kit is 104977 at this link: 14977 } UPGRATE KIT FOR WORM GEAR - Salem Power Equipment, LLC

They dont say what the upgrade consists of but suspect a new fan with new shear bolt design, new flange piece to slip over fan shaft to mate to new fan shear bolt and probably upgrades within the gear box itself.

A call to them might yield a lot of info.

Dave M7040

 

[JWR]

jrogers -- some of this has been interesting and/or educational, but your situation is ridiculously out of hand. Find the dealer who sold the thing to you and demand that they back the product -- make them figure out what the problem is...no matter who has to pay for it. Nothing else makes any sense at this point.

 

[jrogers]

JWR,

I bought it used, but there is a local Kubota dealer. I am thinking after the winter is over (or at least the snowfall) I will take it down there for them to look at and see of they can figure it out. I am thinking that it is all of the sand, and the size of the sand vs. the gap between the housing and the fan. One idea I had to test this was to spray the housing with a thick, plasticized paint like on tool handles to take up the gap on a temporary basis and see of this causes the gravel to make it through. I am not convinced that the gravel is the problem though, since the last shear bolt went when I was 100 yards away from the main road where the gravel is at -- by maybe it does not get pushed out right away and just rolls around in the fan until it jams...

Thanks for sticking with me and all of the suggestions.

 

[Dave M7040]

I have been posting about shear bolt failures being experienced by the owners of front mounted blowers which are driven by mid pto's. My comments are negative. I was surprised to find an email in my inbox from: CustomerService@Kubota.ca. with the topic Shear Bolt failures.

I have not opened the email fearing a virus but checked and Kubota Canada posts that same email address.

I sent an email to that address at Kubota.ca saying I received an email looking like it came from them but I would not be opening it.

I suggested if they have anything to say about shear bolt failures they should join the forum(s) and disclose who they represent. I also said many frustrated owners would like to have a person at Kubota to deal with.

Have any of the forum members been contacted by Kubota like this?

Dave M7040

 

[jrogers]

Well the problem is not sand. I just went through 4 shear bolts in an hour, and I was just plowing through 6 inches of fresh snow on pavement, no where near any rocks or gravel. I am going to go back and revisit the phasing issue, and maybe even rotate it 90 degrees to see if this helps. It seems to take a bit longer to break the bolts if I throttle back a bit, but not much difference. The bolt parts I recovered are looking pretty beat up for only being in there for 15 minutes or less. I will post a picture of a couple of them when I get the chance.

 

[JWR]

I have been posting about shear bolt failures being experienced by the owners of front mounted blowers which are driven by mid pto's. My comments are negative. I was surprised to find an email in my inbox from: CustomerService@Kubota.ca. with the topic Shear Bolt failures.

I have not opened the email fearing a virus but checked and Kubota Canada posts that same email address.

I sent an email to that address at Kubota.ca saying I received an email looking like it came from them but I would not be opening it.

I suggested if they have anything to say about shear bolt failures they should join the forum(s) and disclose who they represent. I also said many frustrated owners would like to have a person at Kubota to deal with.

Have any of the forum members been contacted by Kubota like this?

Dave M7040

I was contacted by 2 different AGCO reps about the same problem this past week. Ordinary emails. I think you were aware that MF (e.g. AGCO) has the same issue reported on these forums all tracking back to the same OEM brand front end snowblower. I told them I was not the customer/owner/user of the units with trouble and pointed them back to the forum so they could make contact.
So far as I could tell they were genuinely interested in trying to get to the bottom of the problem. One was replying to my email to AGCO asking if they were going to issue a recall or if they were aware of the problems. The other was from "AGCO Answers" customer service people. By the way, as long as you have your computer anti-virus software set to protect you (normal defaults, standard stuff) you are in no danger opening an email. You'll never be hit just opening an email if you are using any of the standard antivirus programs. You ARE at risk opening attachments to emails, not emails themselves. I use Microsoft Security Essentials (which is free) on 3 machines at our household and 2 others that I have installed for people. Never heard of a breakthrough in many years.

 

[Dave M7040]

JWR

Please don't take my reply as being in anyway a negative response to your opinion on the risks involved with this email.
On the orange forum where I also posted this concern, a member also suggested to open it.
I asked him to pm me his email address and I would try and forward it unopened.
I just finished dealing with a nasty virus masquerading as the major Canadian Telco and internet provider doing a customer survey.

It was in a link a trusted friend sent me concerning research at a University we were both involved in.

I am always concerned when I cannot click on reply or forward an email before opening it.

If Kubota will formally come on the forum with the intention of making its customers happy, it is a win win situation for everyone.
I recently got a threatening email from an American Attorney representing some Hollywood giant.
My son forgot to use his VPN software when he was here to visit and proceeded to bit torrent download USA stuff.

I am old and, at times foggy from opioids, and just try and keep my life simple.

Dave M7040

i

 

[JWR]

No problem, quite alright. I find tractors and farm equipment to be a great escape from the arcane business of the computer world. You're old ! I'm 74 this year and headed for your country to ski next week.

 

[Dave M7040]

No problem, quite alright. I find tractors and farm equipment to be a great escape from the arcane business of the computer world. You're old ! I'm 74 this year and headed for your country to ski next week.

JWR

I too loved hiking, cross country and downhill skiiing.
Also like high tech solutions to problems.

Had serious pain issues from a neck injury and after 8 years on heavy duty opioids elected to have a neurostimulator implant.

Electrodes placed beside my spinal cord in my neck and a black box in my abdomen.
A special belt to wear to charge up the black box. Remote control to adjust the black box.
No more welding because of the strong magnetic fields so gave away my welders.

It all went wrong and I ended partially paralyzed from an infection around the electrodes which compressed my spinal cord.

The photo to remove the infected tissue and bone + the electrodes left this hole in my neck.
I was sent home to grow new tissue to fill the surgical hole.

Sorry if it offends anyone. I shrunk is as much as I could. Now more pain and more opioids than ever. Hospitals are a dangerous place to go.
All my welders are gone but because the stimulator was ripped out I am allowed to weld again.

Dave M7040

p.s. I apologize to the originator of this thread for going so far from it.

 

[jrogers]

Here is a picture of a couple of the many sheared bolts:



More interestingly, here is one that was in the tractor for about 10 minutes:



You can see how it is already getting beat up. Looking at the tab where the shear bolt goes in, it is a bit loose, especially the back tab. I tried wrapping the bolt in some metal putty stuff that should harden and fill the gap. It seems like the correct solution would be to weld the hole and redrill it, but that seems like it would be hard to do without a lot of disassembly.

On another note, I pulled the drive shaft apart, and the shaft is not square, but slightly rectangular, so there is no way to assemble it where I would cause the phase problem previously mentioned.

 

[Dave M7040]

jrogers

I pasted an early post of your which clarifies a few things.

When I said second stage, I meant not the auger but the fan (the vertical section). I rarely shear the auger bolts. The bolts I have been getting are from the kubota dealer, so I am assuming that they are giving me the right thing. We have had some warming and cooling, so the driveway has had some 'traction sand' put on it, which has some coarser sized pebbles in it that may be causing the issue, maybe a 1/4" in diameter. Thanks for the advice on running the blower at full speed as well as torquing the bolts tight, those are both things that I have been wondering about. I took the time today and greased all of the fittings on the blower. It probably won't help but certainly won't hurt.
Below Dave M7040
Is this image of a new blower's fan shear bolt the same as you blower?

Do you have a venier caliper, even a plastic one from home depot.

The usefullness of the probe coming out is to measure the depth of a hole. In your case you are going to press the big end where the probe comes out against the area where the shear bolt goes in and extend the probe until it is just flush with the other side of the home.

Lock the caliper in that position with the small thumb screw.

Place the probe against the underside of the head of the shear bolt and take a photo which will show where the depth of the hole is on the shank area of the shear bolt.


Can you post a picture of the bolt in your second photo in place on the blower. Also measure the length of the bolt from the top of the head to the end of the threads at the tip.

The thread area is all deformed. The threads should be outside where the shearing action is to happen.
The threads are just to keep the smooth shank of the shear bolt in place until the time its protection is needed.

For the threads to get beat up near the un threaded shank tells me something is amiss with the amount of threads on the bolt shank.

Would you post a picture of the second photo bolt in place be certain to get a shot of the head of the bolt.

If as I suspect, when the second bolt is in place, there is no smooth shank just at the edge of the shear bolt hole, then I think you need a longer bolt or a bolt where the shank is smooth for a greater distance.

Where do these bolts come from? A Kubota part # or a general supplier of bolts and nuts. There is a length of bolt where the amount of thread is suddenly reduced compared to the lower size.

I think it is 1-1/2" has fewer threads than 1-1/4".

Looking forward to seeing the requested pictures as I think it will explain a lot.

Dave M7040

 

[PILOON]

Well I am a new member to the sheer bolt club as I have been sheering like 3-4 /hr , this on my fan.
What has happened is that I used hardware store bolts that were supposedly graded but I guess they weren't and as a result they stretched and messed up the holes so they no longer simply shear.

So what I'm doing is drilling out to oversize, in this case 5/16, and hope that I'm good to go.
Changing shear bolts every 15 mins is no fun!

 

[jrogers]

So what I'm doing is drilling out to oversize, in this case 5/16, and hope that I'm good to go.
Changing shear bolts every 15 mins is no fun!

The problem is that if you move up to a larger size hole and shear bolt, you are also moving up to a higher shear force, unless you are able to find bolts that are rated for the same shear force as what you where previously at.This may be possible by getting a bolt with grooves in it, but I don't know what they want for the rated shear force, I just buy the Kubota bolts.

 

[JCByrd24]

I think I'm correct in that you have a different shear bolt arrangement than what Dave shows in post #92, in that you have a hub with the shear bolt off to the side. I think there was a picture earlier. This is very similar to a JD and the distance from the center of the shaft looks about the same or shorter. The JD uses 1/4" grade 5 vice 2. I think you could easily go to a 5 if you have not already without fear.

With that type of arrangement there should be no wear before shearing in my opinion. The bolt should be snug enough that it's holding the two hubs together and the friction imparted means the two hubs don't rattle or move with respect to one another. The unidirectional loading should mean the same thing really, but if loose the engagement and disengagement of the PTO could wear the holes/bolts. The wear you show in your photos suggests to me it's not tight enough. This would not be true with the design Dave posted and in my opinion that is a worse design as once those holes started to wear it would get progressively worse.

This brings me to another question. How is the PTO engaged on your B-series? With a clutch you control or instantly via an electric clutch of some sort. If the latter I would caution that you need to drop the engine speed down to just above idle when engaging the PTO. My Yanmar engages with the same clutch pedal as the tractor so I can feather the engagement even at full throttle.

 

[Dave M7040]

Well I am a new member to the sheer bolt club as I have been sheering like 3-4 /hr , this on my fan.
What has happened is that I used hardware store bolts that were supposedly graded but I guess they weren't and as a result they stretched and messed up the holes so they no longer simply shear.

So what I'm doing is drilling out to oversize, in this case 5/16, and hope that I'm good to go.
Changing shear bolts every 15 mins is no fun!

Piloon
So you live in Quebec where RAD is.

Go and pound on their door for a solution.

On a more serious note, to be safe post a picture of what you have and the shear bolt area where you are having problems.
If we don't understand exactly what you have, you could receive advice that would or could be damaging.

I sent an email to RAD. I received a reply from CustomerService@Kubota.ca

If you don't have the latest fan hub with flange design and related flange part on the fan shaft, then all efforts are wasted and you could end up with a gear box in pieces which, I am told is $700.

If you or anyone else want to see the lengthy email I replied to the Kubota rep, send me a pm with your email and I will forward it to you as it is too long to post here.

Dave M7040

 

[PILOON]

Well I am a new member to the sheer bolt club as I have been sheering like 3-4 /hr , this on my fan.
What has happened is that I used hardware store bolts that were supposedly graded but I guess they weren't and as a result they stretched and messed up the holes so they no longer simply shear.

So what I'm doing is drilling out to oversize, in this case 5/16, and hope that I'm good to go.
Changing shear bolts every 15 mins is no fun!

Well so far so good.
Just did 2 drives, about 2 hours of tractor time all with the same bolt so life is good.
In many cases I had a full load, enough to want to lower the RPM's so I was working to the limits.
Being somewhat leery of damaging things I used 5/16 regular rather than graded bolts and they held up as I hoped.
Come decent work weather (summer?) I'll install bushings and return to 1/4" bolts but to do that the fan needs removal which means total take down and at which time I'll probably renew bearings as well and do a general overhaul.

On the positive side I have a good base (read stone free) so should not catch any sheer breaking stones or other junk in which case that one 5/16" bolt might just last the remaining season.
Also intend to add belting to the paddles to close up that gap, fact is the 'generous gap' is my main cause of troubles as stones get wedged in there and trip the sheer bolts.

 

[JWR]

Looking at Dave's post #92 -- any of you using that design (shear bolt thru the shaft) are much more susceptible I think. In that design tightening the bolt does nothing to snug the shaft and the housing together because the housing metal is too thick. In that setup you are totally dependent on the bolt being tight in the hole and have no control over it. If the hole has become distorted due to repeated breakages the problem will keep getting worse. If it were mine I would do as Piloon said and drill it out to use 5/16" bolts. But in doing that you have to be very careful not to drill an enlarged imperfect hole even if it is 5/16". Another thing is to "search the bolt bins" and purposely pick a shear bolt with just enough threads to tighten against the housing hole and NOT enough threads to go down inside the housing. Point is you don't want threaded area in the region of shear. I would not be afraid of using 5/16" grade 2 bolts at all.
Another thought about those of you shearing really large numbers of pins even on light snow and in very short time, that circumstance is what has baffled most of us approaching 100 posts now. If it is THAT bad (and a used blower where you cannot just insist on dealer assist) I would set the whole rig up to run in the open on concrete -- no load, no snow. As light a load as some mentioned and still getting shear it will probably do it sitting there in the open under what SHOULD be no-load. That way you can test for "slop" in each pin area, noises, wobble, etc. Might even wonder if bearings are on the way out and periodically jambing and resisting turning.

 

[aczlan]

Another thing is to "search the bolt bins" and purposely pick a shear bolt with just enough threads to tighten against the housing hole and NOT enough threads to go down inside the housing. Point is you don't want threaded area in the region of shear.

Yes, I would pick a shear bolt that has a shoulder long enough to hit both sides of the shear area.
If needed, you can shorten the threaded section to be just longer than the nut.
I had to do that with the shear bolt on our hay baler.

Aaron Z

 

[jrogers]

Yes, I have the updated shear bolt setup in mine:



Here is the bolt in the package from Kubota:



The total distance of the two flanges lined up is around 3/4". The thread on the bolt could be 1/4" shorter in my opinion.




And here is the head of the bolt. This is a grade 8 bolt, right? Seems like no where to step up to other than to go to a 5/16".



The last bolt I pulled out had a bit of a bend to it, even though it was only in there a short time. They seem to loosen up quickly. I assume that it is stretching the bolt.

I can get pretty good access to the two sides of the flange. It seems like a good, permanent solution would be to weld up the holes and redrill them, as they are a bit loose right now. I will try and find another grade 8 1/4" bolt with a longer flange (less threads). The JH label on bolt head indicates the Chinese manufacture. Maybe they are not really grade 8 or they have some manufacturing problem?