Shear bolt madness

[Soundguy]

Well, for one thing you will never know the correct spot to drill. And 2, even if you did, the old shank will just spin in the shaft = no drilling. You say, "just use the correct tool for the job". Please tell us what the correct tool is to remove that old shear bolt shank?

can you see the shank straight on or not? if you can, then go for center. if it's stuck hard enough you can't drive it out, it should hold still to be drilled. if it does by chance start turning, then switch to a left handed bit and see if you can suck it out of the hole. I've had to also drill into stuck bolts and then screw in a deep thread lag bolt then use a slide hammer on them.

In extreme cases, you burn the pin out either with a peircing tip on a torch, or go at it messy with a chamfer rod.

if you can post a clear close up of the area it might help a little more.

 

[kfeuerherm]

This is what I have done on a half dozen occasions; Move the augers so there is maximum clearance directly in front of the fan. Expand and slide the C clip back so that it is close to, but not touching the gearbox. Rotate the fan so that the blades will clear the housing. It will not pull forward in just any position. Use a bit of penetrating oil and work the fan back and forth until the shaft hole is fully clear of the fan. The remains of the sheared pin should drop out. Return the fan to its proper position, if the holes do not align, use a pin punch from one side to help align them. Insert new shear pin, it may help to put a slight a taper on the end of the new pin. Tap the new shear pin into place. Replace C clip.
I believe the problem is caused by the fan bushing which is not seating properly and causing forward tension on the fan. This summer I will be investigating and repairing.

Ok, back last night, to find this morning that a sewer pipe had frozen while we were away so spent most of the day working on that; got to the blower late in the day.

Got myself retaining pin pliers and moved the C-clip. Found the fan will not come forward due to paint. Spent a fair amount of time sanding off paint. Then found it will come so far forward, but not all the way; something stops it dead. Perhaps the key is as stated above rotating the fan; but to clear the housing that gives only limited choices.

No luck with the inspection mirror. Tried a heat gun too.

It's now getting too cold to continue so I guess I'll try again tomorrow.

 

[don white]

The shear bolts systems described here are just plain bad engineering. No way it should take that much effort to change a shear pin. I had one blower that had a sheer bolt. It was on the chain sprocket. A flange with a hole was welded to the shaft. It was a two minute job to change. I did however hack around with finding the right material to make it out of. First I used Bronze but that was two soft. Ended up with cold rolled steel. I do not agree with using a grade 5 bolt. You should probably buy the OEM part and try to determine how hard/tough it is.

I have a B26 with a blade but I also have a Simplicity with a snow blower. It has no shear pin. What it has is a long belt and spring loaded tension idlers. I have a 1100 foot stone driveway. That system really does work.

 

[kfeuerherm]

The shear bolts systems described here are just plain bad engineering. No way it should take that much effort to change a shear pin. I had one blower that had a sheer bolt. It was on the chain sprocket. A flange with a hole was welded to the shaft. It was a two minute job to change. I did however hack around with finding the right material to make it out of. First I used Bronze but that was two soft. Ended up with cold rolled steel. I do not agree with using a grade 5 bolt. You should probably buy the OEM part and try to determine how hard/tough it is.

I quite agree. I was thinking that down the road maybe if I lengthened the sleeve and put the new bolt hole farther forward, or else used a flange system (my friend's blower works that way) it would be much easier to deal with.

I am using the OEM bolt btw which is listed as grade 8.

 

[muskoka kubota guy]

The shear bolts systems described here are just plain bad engineering. No way it should take that much effort to change a shear pin. I had one blower that had a sheer bolt. It was on the chain sprocket. A flange with a hole was welded to the shaft. It was a two minute job to change. I did however hack around with finding the right material to make it out of. First I used Bronze but that was two soft. Ended up with cold rolled steel. I do not agree with using a grade 5 bolt. You should probably buy the OEM part and try to determine how hard/tough it is.


I have a B26 with a blade but I also have a Simplicity with a snow blower. It has no shear pin. What it has is a long belt and spring loaded tension idlers. I have a 1100 foot stone driveway. That system really does work.

For most people with these blowers, it's simply a matter of lining up the holes, dropping the new pin in, and snugging up the nut. The whole process doesn't take but a minute or two. In my case, there is something else going on. I just need to take the time and resolve it. I think it is more of a manufacture defect than a bad design.
The system you have does sound pretty sweet though!

 

[kfeuerherm]

For most people with these blowers, it's simply a matter of lining up the holes, dropping the new pin in, and snugging up the nut. The whole process doesn't take but a minute or two. In my case, there is something else going on. I just need to take the time and resolve it. I think it is more of a manufacture defect than a bad design.
The system you have does sound pretty sweet though!

The keyword is 'most'! This morning, with a deck screw (i.e. pointed thing) I was able to locate the bolt, it is exactly where I thought. I could feel around the edges and the bump in the middle. Pounding at it did me no good.

BUT I now managed to get the fan out the rest of the way!! It was jamming on the burr. (See photos, from the left, then zoomed in so you can see the fan out, then two shots of the sheared pin.

So, the procedure has been (leaving out failed things): 1) move retaining pin from ahead of fan out of the way 2) sand off the paint so the fan can come forward (sandpaper actually worked better than power tool) 3) push, pull rotate, repeat, many times until the fan comes forward.

Now, to work on the pin....!

 

[kfeuerherm]

Let me add to the saga right now.

Even with the pin visible, and banging on it directly with the punch, it won't budge.

So I decided that I'd try the other side. But that means rotating the shaft; which means moving the fan back. Move the fan back, rotate the shaft, discover this cannot be done because the augers are in the way of the fan moving forward. Put it back, try to get the fan out, gets stuck again. Finally get it out, now sand the shaft behind the fan to get the rust off so it will come forward....

So it looks like now I may have to take the other two pins out so that the augers spin freely and I can get the hole where I like. And it looks like like it or not, I'm going to have to drill somehow, or go at the pin with the Dremel or something.

I cannot believe this was designed this way!

 

[PILOON]

Studying the pics I believe that the sheared pin is a softer hardware bolt *that left burrs when sheared.
Generally grade 5 bolts are what most specify as the shear clean.

In as the location is so difficult to service perhaps you want to use a high grade like 10 or so and add a drive shaft shear protection system like used on bush hog mowers. Just a thought.

*In a pinch I once used a 5" nail as protection and that was the worst ever alternative.
Took me forever to remove and the holes were mangled for life with every subsequent pin a challenge to remove.
A shear pin hole is just as the name suggests, A SHEAR, and shears (scissors) want sharp cutting edges, not rounded over edges.

 

[kfeuerherm]

Solved!!

It was the original OEM bolt that came with the unit, so by specs it would be grade 8.

I drilled a half inch hole in the cowling and my plumber who was here thawing our sewage drain put a long punch through the hole, and he reefed on that sucker with his heavy ball peen hammer several minutes before it came out.

There is no way on earth it would have come out without resorting to such extremes. Anyway, now I have the hole for future use.

Next, have to put the fan back in, put the other two shear pins back which we removed so we could rotate the augers out of the way (one of which was bent btw, so it's getting replaced too), then grease the shaft which I have sanded....

What an ordeal!!

I thank everyone who took the time to offer some advice about this problem. I've attached a pic so that anyone else who has to pull out the big guns can see how I did it. The hole is high up on the cowling midway across as you can see.

 

[don white]

Well I hope you have your night mares straightened out. I hate it when problems pile up like that.

Well the snow blower is broke and I can't even take a crap. I feel for ya and have been there.