Woodmaxx Snowblower Shear Bolts?

[KanakaRick]

I just got a SB84 for my DK50 tractor, and the shear bolts which came with it for the PTO to the gearbox are snapping like twigs. The manual says they are grade 2, with I would expect to break very easily. What grade are you guys with the same blower using? Grade 5? Grade 7? I was blowing champagne powder this morning and I went through about 10 shearbolts on that PTO to gearbox connection. It made it a serious pain in the butt and made the "blower" just about useless. I probably wouldn't get 2 feet in Sierra Cement with those stock bolts.

 

[RNeumann]

Sounds like a bad batch or wrong size. Going to 5 or 8 could cause other parts to break. The other possible issue is something else is binding. It definitely shouldn’t be breaking like they are.

You can try breaking on of the bolts in a vise and see what it does compared to others.

 

[KanakaRick]

Sounds like a bad batch or wrong size. Going to 5 or 8 could cause other parts to break. The other possible issue is something else is binding. It definitely shouldn稚 be breaking like they are.

You can try breaking on of the bolts in a vise and see what it does compared to others.

Yeah, it is crazy. I literally have the blower sitting on the ground, with no snow around, and I turn on the PTO, and the bolt breaks. Yet, I can turn the pto and blower components by hand with the tractor off. So nothing is binding. But I turn the tractor on, and turn on the PTO and the bolt breaks, WITHOUT actually touching the snow I need to blow.

 

[PEJ5]

Time to contact the company to get a professional opinion. Their website says grade 5.
84" Snow Blower, Tractor Snow Blower, Hydraulic Chute Rotation - WoodMaxx

My Lucknow blower PTO shaft takes a metric grade 8.8 which is equal to SAE grade 5.

 

[KanakaRick]

Time to contact the company to get a professional opinion. Their website says grade 5.
84" Snow Blower, Tractor Snow Blower, Hydraulic Chute Rotation - WoodMaxx

My Lucknow blower PTO shaft takes a metric grade 8.8 which is equal to SAE grade 5.

Yeah, I will call them in the morning. I put a grade 8 bolt in there. Both the pto drive and the blower free wheeled so nothing was binding either of them. Turned the tractor on. Idled it down and turned on the pto (on my snow-free driveway) and the grade 8 bolt snapped before it even saw a lick of snow. Something is amiss.

 

[atsah]

Something wrong for sure. I have used my Blizzard on hard packed bankings that made it sound like a wood chipper and I didn't break a bolt.

 

[KanakaRick]

The only possible thing that I think it could be.... is in the instruction manual, the photos of the way the pto shaft is set up is opposite of the way mine is. They show the outer sleeve of the adjustable PTO shaft attaching to the tractor, and in my PTO shaft, the outer sleeve has the U joint that takes the bolt at the gear box and the slide in part (inner sleeve) is attached to the tractor with the pull back collar (which I am also have serious issues with trying to put it on). And what I discovered today is when I was done trying to use the blower and tried to take the blower off, the inner and outer sleeves were frozen together because the water from the inner (attached to the tractor) must have dripped down towards the outer sleeve (pointing upward on the blower) and they froze together. So no sliding it off there, without heating it up and moving the tractor. It is (in my mind) beginning to make sense that the pto shafts have the wrong U joints at the wrong ends. But would just that make a difference on breaking shear pins?

 

[atsah]

Can you post a picture of your shaft setup. It sure sounds like something isn't setup correctly.

 

[RNeumann]

The frozen sleeve could be pushing or pulling on the blower gear box as you raise and lower the slower. This could cause it to bind and break bolts. Leave that driveshaft above freezing till it thaws and get some more grease in it. Put it on properly and give it a test. I think that will go a long ways to fixing it.

FYI- it will only stop snowing when it’s fixed so get on it!

 

[KanakaRick]

The frozen sleeve could be pushing or pulling on the blower gear box as you raise and lower the slower. This could cause it to bind and break bolts. Leave that driveshaft above freezing till it thaws and get some more grease in it. Put it on properly and give it a test. I think that will go a long ways to fixing it.

FYI- it will only stop snowing when it痴 fixed so get on it!

But I am not moving it up and down. It is sitting on the edge of the driveway, 2 feet away from the snow I am going to blow.The box is level, a couple of inches off the ground. The tractor is idling, I turn on the pto, and the grade 8 bolt breaks. I never get a chance to even put it in gear to move it towards the snow.

 

[KanakaRick]

Can you post a picture of your shaft setup. It sure sounds like something isn't setup correctly.

As soon as the wife gets off my computer

 

[KanakaRick]

The manual says the outer drive line is attached to the tractor, and the drive line they sent me, the outer drive is attached to the blower, so all the melted water runs down the driveshaft and freezes the two covers together. So possibly one of the guys in the shop may have gotten the U joints confused with which side of the drive line it went on..... but the big question, would THIS make that much of a difference?

In another thread in the Kioti forum, I am having huge issues with sliding the detent collar on to the PTO driveshaft on the tractor. It slips in nicely until it gets to the detent part of the PTO shaft, and then I literally have to call a neighbor over so he can hold the collar back, while I hammer with a block on the U joint to get it to slide on the PTO shaft. It slips off with no issue, but it a real bugger to put on- it truly is a 2 man job. I am thinking both issues are related to "possibly" having the shaft with the wrong U joints on the wrong ends? I have no idea what else it could be?????

 

[canadianstrom]

The pto angle looks fairly extreme , could contribute. I dont think the outer shields freezing together would be the issue ( if thats what you meant) . it looks like the shaft ends are in the correct orientation . Maybe shaft cover was put on wrong but thats not important.
The angle would also make the install on the shaft difficult

 

[KanakaRick]

The pto angle looks fairly extreme could contribute. I dont think the outer shields freezing together would be the issue ( if thats what you meant)
The angle would also make the install on the shaft difficult

The freezing part is the least of my worries. When I am slipping the collar on, I line everything up so it is all level, so it should slide on

 

[Fallon]

I concur, the angle looks a bit steep, but not to bad.

The inner or outer shaft being attached to the tractor shouldn't make any difference, other than the freezing issues. The shafts are hollow & open at the U-joints so moisture can still make it in. Less likely if the outer shaft is uphill.

All modern PTO shafts are keyed so you cant put them together wrong. If they weren't you can get the U-joints out of phase, which causes big vibration & other issues. It's possible it could be setup bad from the factory, but not super likely. shaft phasing - YouTube is an old video & not super exciting, but very informative on the subject.

 

[atsah]

If you lift the blower until the driveshaft is level and then turn the blower on does it
Break the bolt?

 

[KanakaRick]

I cant do anything about the angle.... I guess A call to Woodmaxx is in order. Hopefully there will be someone there at customer service tommorrow

 

[KanakaRick]

If you lift the blower until the driveshaft is level and then turn the blower on does it
Break the bolt?

I didnt try that, as I needed it lower to blow. That would be a good test..I took it off as I needed to do snow removal.... I'll call woodmaxx tomorrow, and see what they think

 

[leonz]

A grade 8 bolt will break by shearing it has its greatest strength from a tensioning standpoint.

If you have a space heater or could borrow one you need to melt the ice out of that PTO shaft sleeve. Your entire shaft may be bent and the bend is just enough to shear the bolts.

 

[RNeumann]

From the photos I see you have a hydraulic tip link that looks fairly extended.

Another SWAG is too much angle on the driveshaft. I’d have to go back to my Jeepn’ days but their are maximum driveline angles. The other issue occurs when the two U joints aren’t at the same angle. U joints don’t rotate at a constant speed- if they are at different angles, it can cause different frequency which could also cause the failures. This to me is a SWAG compared to the frozen, backwards driveline. But I thought I’d mention it after seeing that top link. Good luck with the manufacture!