Snowblower Kubota b2782b - bolts sheared

jmatz · Feb 2, 2019

The bolts that pass through the retainer and attach to the large drive gear have sheared. You can see the raw, broken end of one of the bolts in the drive gear.

I've been told that the two threaded holes in the retainer are for passing a couple bolts through to push the retainer away from the gear and slide it off the end of the shaft. Makes sense, but I don't want to do that until I have two new replacement bolts for the ones that got sheared off.

I'm not sure what to do about the square shaped key that sits in the groove of the shaft... does that have to come out first, and if so, how is it removed?

200mph · Feb 3, 2019

Use the provided threads and two new bolts to push the two parts apart. Doing so will loosen the gear from the shaft. The 1/4" square key-way can stay in place.

There is a taper designed into the two parts so the closer they come together the tighter they are on the shaft. Spreading them apart relieves the compression on the shaft.

Have fun and good luck.

kevinj · Feb 3, 2019

If you sheared them bolts it was not put together right.

thebicman · Feb 3, 2019

That's exactly how it comes apart. Find two bolts that fit the holes and alternate screwing them in to work the retainer off evenly. You can also use a small puller to pull the collar off. The big question is why did the bolts break? Getting the retainer off is the easy part. Hopefully you can get the broken bolts out without too much trouble.

jmatz · Feb 3, 2019

Thanks to all of you!

There are two slots in the shaft - do you think there should have been a key in both slots?

Luckily, we have a short thaw happening in northern Michigan, so I won't need to do any snowblowing until later in the week.

I will report back once I fix the thing.

kevinj · Feb 3, 2019

jmatz said:
Thanks to all of you!

There are two slots in the shaft - do you think there should have been a key in both slots?

Luckily, we have a short thaw happening in northern Michigan, so I won't need to do any snowblowing until later in the week.

I will report back once I fix the thing.

Take some better pics when you take it apart, I do not see the QD type sprocket at Messicks.

The QD hubs work great if put together right.

thebicman · Feb 3, 2019

Not sure why there is two keyways only one key is used. I checked the parts break down on Kubota parts.

Tughill Tom · Feb 3, 2019

jmatz said:
The bolts that pass through the retainer and attach to the large drive gear have sheared. You can see the raw, broken end of one of the bolts in the drive gear.

I've been told that the two threaded holes in the retainer are for passing a couple bolts through to push the retainer away from the gear and slide it off the end of the shaft. Makes sense, but I don't want to do that until I have two new replacement bolts for the ones that got sheared off.

I'm not sure what to do about the square shaped key that sits in the groove of the shaft... does that have to come out first, and if so, how is it removed?

View attachment 40564

View attachment 40565

https://www.absolutaire.com/sites/default/files/public/documents/split-taper-bushinginstall.pdf

It's a split taper bushing look at the attachment and do as they say. Just saying.... 30 +years in industrial maintenance have learned things the had way.

kevinj · Feb 17, 2019

So, did you get this fixed?

jmatz · Feb 18, 2019

Sorry for the slow update. While messing with the retainer thing, I tapped it further along the shaft towards the gear, which seems to have created enough friction to lock the gear to the shaft (maybe the key is also keeping things locked together?) and allow the auger to rotate at full rpms and blow 2-foot drifts approx 20 feet off the driveway and road.

We haven't had enough of a break in the snow to allow me to do the repair. But I have been able to buy stainless bolts that match the thread size and pitch to replace the sheared ones in the gear, and also to thread into the retainer to push it away from the gear when I am ready to fix things.

When there is a for-sure break in the snow for a couple days, I'll do the repair.

Will report back soon!

kevinj · Feb 18, 2019

It is not a gear - it is a sprocket.

See tugs post with a link about putting a QD together properly.

If you are running that without bolts you may as well order a new sprocket & bushing.

If it is worn from running loose you will never hold it.

bumper · Nov 26, 2019

Any updates on this? Please!

I have the same problem, storm coming it, went to lube things and found the a bolt sheared and the other bent in the gap and of course sheared when I went to remove it. Now having a devil of a time getting the split collar to back off.

jmatz · Nov 27, 2019

bumper said:
Any updates on this? Please!

I have the same problem, storm coming it, went to lube things and found the a bolt sheared and the other bent in the gap and of course sheared when I went to remove it. Now having a devil of a time getting the split collar to back off.

Well, I put it off all summer of course. But a couple weeks ago I screwed two bolts in to the threaded holes in the collar and slowly applied pressure to each one, alternating between the two. The collar never even budged. The two bolts just eventually snapped when I applied more pressure than they could handle. The threads were not damaged so I was able to use vice grip pliers to back them both out of the holes. Not sure what is holding the collar in place - but assuming that it is just friction and the little square key that is still wedged in the groove. The two bolts that are intended to hold the whole assembly together are still there, sheared off down to where they enter the main gear.

We had a major snow coming (northern Michigan), so I just left things as they were, lubed chain, augers, etc.. and went at it. Blower worked fine on approx 18" of dense snow. Now that it has all melted, I'm going to have another look to see if the two days of use managed to loosen the collar at all.

If I can't loosen it, I will assume that it will stay that way for the rest of this winter, then will take just the blower to the dealership in spring. I think they must have a specialized tool that can pull that collar off.

All I can suggest for your situation is to firmly tap the collar further on to the shaft to produce a tight friction fit. Maybe it will be enough to keep the augers and second stage all spinning, especially if you take it slow through the drifts. If not, and it begins to slip, then maybe it has loosened the collar and you can then take it off. If it's already jammed on there and won't budge, then you're probably going to be able to use it normally until you can get it to loosen up when there's no pressure from an oncoming storm.

I'll let you know if I find out anything new.

TimP · Nov 27, 2019

Thanks for the update jmatz.

I also have a B2782B blower and am wondering if this is something that isn't real unusual. (Bumper says he has the same problem)

I can't imagine what would make those bolts break/shear.

Dave_eng · Nov 27, 2019

jmatz said:
Sorry for the slow update. While messing with the retainer thing, I tapped it further along the shaft towards the gear, which seems to have created enough friction to lock the gear to the shaft (maybe the key is also keeping things locked together?) and allow the auger to rotate at full rpms and blow 2-foot drifts approx 20 feet off the driveway and road.

We haven't had enough of a break in the snow to allow me to do the repair. But I have been able to buy stainless bolts that match the thread size and pitch to replace the sheared ones in the gear, and also to thread into the retainer to push it away from the gear when I am ready to fix things.

When there is a for-sure break in the snow for a couple days, I'll do the repair.

Will report back soon!

Please note important info on stainless steel bolts (fasteners). They have their place but if strength is a requirement this is not what you need.

ARE STAINLESS STEEL BOLTS STRONGER THAN STEEL?

In fact, due to their low carbon content, many stainless steel alloys cannot be hardened through heat treatment. Therefore, when compared to regular steel, the stainless alloys used in bolts are slightly stronger than an un-hardened (grade 2) steel but significantly weaker than hardened steel fasteners meaning grade 5 and grade 8.

Dave

jmatz · Nov 27, 2019

Dave_eng said:
Please note important info on stainless steel bolts (fasteners). They have their place but if strength is a requirement this is not what you need.

ARE STAINLESS STEEL BOLTS STRONGER THAN STEEL?

In fact, due to their low carbon content, many stainless steel alloys cannot be hardened through heat treatment. Therefore, when compared to regular steel, the stainless alloys used in bolts are slightly stronger than an un-hardened (grade 2) steel but significantly weaker than hardened steel fasteners meaning grade 5 and grade 8.

Dave

Very helpful, Dave. Yes the bolts I used were stainless. I will find some grade 5 or grade 8 bolts and try again.

jmatz · Nov 27, 2019

TimP said:
Thanks for the update jmatz.

I also have a B2782B blower and am wondering if this is something that isn't real unusual. (Bumper says he has the same problem)

I can't imagine what would make those bolts break/shear.

I agree - all I can think of is maybe my shear bolts on the augers are not the correct rating and are not breaking easily enough when needed, so putting more stress than the rated amount on the bolts that hold the retainer and main sprocket together.

DustyRusty · Nov 27, 2019

jmatz said:
Very helpful, Dave. Yes the bolts I used were stainless. I will find some grade 5 or grade 8 bolts and try again.

I would purchase the bolts from Kubota, since with a lot of hardware coming from China, there is no guarantee that what you buy thinking that it is a true grade 5 or grade 8, really is up to the specification.

Dave_eng · Nov 28, 2019

Some Kubota shear bolts have grooves cut in them to weaken them.

You need to be very careful with what you use or a broken gear box is possible.

Dave

kevinj · Nov 28, 2019

jmatz said:
I agree - all I can think of is maybe my shear bolts on the augers are not the correct rating and are not breaking easily enough when needed, so putting more stress than the rated amount on the bolts that hold the retainer and main sprocket together.

Read up on proper assembly of a QD bushing.

You can twist a shaft off and should not shear the bushing bolts.

It was not put together properly and it is surely damaged from slipping.

You need a new sprocket and bushing.

Snowblower Kubota b2782b - bolts sheared

Member

Well-known member

Member

Active member

Member

Member

Active member

Well-known member

Member

Member

Member

Member

Member

Member

Well-known member

Member

Member

Well-known member

Well-known member

Attachments

Member