Woodmaxx Snowblower Shear Bolts?

[leonz]

Hello Rick,

Measure the from the center line of the stub shaft of the gearbox on the snow caster and then compare it to the centerline height of the mules PTO stub and please note it on your next response as the propeller shaft HAS TO HAVE a very shallow angle of approach(slope)(rise and run) to the mules PTO stub.

if you have some nylon twine you can visualize this more readily by wrapping the nylon twine around the PTO stub of the mule and then doing the same thing to the stub shaft of the snow caster to obtain the angle.
You either use the top of the PTO Stub and the top of the stub shaft on the gearbox or the bottom of both stub shafts as long as you have wrapped the twine around it 3 or 4 times.
This will only be off by 3/4 of an inch or so due to the diameter of the stub shaft but you will see the angle of the slope and then you will see how it is too high in slope to allow the universal joints to work with minimal stress.

 

[TractorNH]

In all fairness to Woodmaxx, they haven't gone there yet. I am still in discussions with them and they are being reasonable in trying to figure out what is going on. I made the "Bozo" remark as a joke.

Are you dealing with Ron over there? He was very knowledgable and answered a few questions I had when I was setting mine up.

 

[Reb954]

I can't see the pictures well enough to tell what might be causing the shear bolts to break but the angle of the drive line isn't the problem.

I will be curious to find out what is really causing them to break. From what OP has said, it sounds like they are breaking rather than shearing.

 

[KanakaRick]

Are you dealing with Ron over there? He was very knowledgable and answered a few questions I had when I was setting mine up.

I am talking with Joel and James.

 

[Z-Michigan]

1) I was snapping bolts every 2-3 hours use. After getting fed up I called Woodmax and they stated that grade 5 is correct, not grade 2 per my paper manual. They apologized for the mistake. I have switched to grade 5 and only broken one so far. The first replacement has seen heavy use without breaking yet.

2) Regardless of bolt strength, a shear bolt that gets loose will break more easily. These ship with nylock nuts, which I have learned partly from older posts here, partly from personal experience, are worthless for keeping stuff tight. I've had nylock nuts fail to hold on lots of stuff, not only shear bolts. I now use threadlocking compound (Vibratite VC3) AND a split washer, and so far so good. This is a few pennies of hardware but seems to make a difference.

3) I agree that the driveshaft angle looks excessively steep, and that using a quick hitch would reduce this angle. I'm running a SB72 on a Kioti DK50 with a quick hitch, and seem to have a reasonable driveshaft angle.

4) The Kioti PTO clutch engages pretty fast and abruptly once warmed up. I was advised to engage the PTO only at idle to reduce the chance of snapping from rapid start-up. My other PTO implements have slip clutches where this isn't an issue.

 

[KanakaRick]

1) I was snapping bolts every 2-3 hours use. After getting fed up I called Woodmax and they stated that grade 5 is correct, not grade 2 per my paper manual. They apologized for the mistake. I have switched to grade 5 and only broken one so far. The first replacement has seen heavy use without breaking yet.

2) Regardless of bolt strength, a shear bolt that gets loose will break more easily. These ship with nylock nuts, which I have learned partly from older posts here, partly from personal experience, are worthless for keeping stuff tight. I've had nylock nuts fail to hold on lots of stuff, not only shear bolts. I now use threadlocking compound (Vibratite VC3) AND a split washer, and so far so good. This is a few pennies of hardware but seems to make a difference.

3) I agree that the driveshaft angle looks excessively steep, and that using a quick hitch would reduce this angle. I'm running a SB72 on a Kioti DK50 with a quick hitch, and seem to have a reasonable driveshaft angle.

4) The Kioti PTO clutch engages pretty fast and abruptly once warmed up. I was advised to engage the PTO only at idle to reduce the chance of snapping from rapid start-up. My other PTO implements have slip clutches where this isn't an issue.

They re-assured me that I do NOT want to use a grade 8- Grade 5 is what I need to use, so the manual is wrong. I am talking with Joel and I reversed the shaft but now my problem is that the collared sleeve won't slip on the output shaft of the tractor (same problem I had with the collar on the other side of the shaft when I was trying to slip IT on to the tractor output shaft). So until I am able to put the shaft on, I cannot tell if swapping the direction will make a difference. Joel tells me the collared shaft is TOO precisely built and I need to file down some of the inner edges to make it sloppier so it will work with my output shaft. He offered to send me a new drive shaft, but across the country means a 5 day wait. So I am going to cut my shaft down (its pretty tight) and go get a file and do some filing and see what happens

Maybe I will pick up a quick hitch just because. If $100 solves this problem than it is worth it.

 

[Reb954]

Out of curiosity lift the blower via the 3PH until the input and output shafts are close to being in alignment, then see if the driveline will slip onto the tractor output shaft.

 

[KanakaRick]

Out of curiosity lift the blower via the 3PH until the input and output shafts are close to being in alignment, then see if the driveline will slip onto the tractor output shaft.

Nada... to tight to do anything. I need to cut the shaft first, then I will try it.

 

[HillStreet]

I use a SB60 on a Kubota B2650 with no issues. I have not broken a shear bolt since new and this is my third year. Bolts are verified grade 5.

 

[KanakaRick]

Ok, I talked at length with Joel and he gave me some ideas, and thus my problem has been resolved. Operator error (or inexperience) Now I know and it won't happen again.

Lessons learned:

1. Apparently their U-Joints with the sliding sleeve are built to super tight tolerances. I literally took a saw flat file and spent no less than 2 minutes filing the insides of the U-Joint couplers and it made a HUGE difference. Now the coupling slides on with literally no effort. Worth remembering.

2. The position of the driveshaft definitely DOES make a difference. I turned it around and suddenly the angle seemed to have become less steep.

3. Since I am mostly blowing a gravel driveway, it makes all kinds of sense to raise the skids to their maximum, since I don't want to be sucking up gravel and I seem to have an driveshaft angle problem.

4. I shortened the driveshaft by one inch and that seemed to have helped too.



I took the tractor out after all those adjustments and it worked great blowing snow. I have another issue with breaking the shear pins, but I cannot hang that on Woodmaxx. Apparently the hydraulic control which is being used as the top link control, in the summer time is used at the flow on control for my backhoe. So when I put it in a forward or reverse position, it stays on and rapidly moves the top link up or down at a rapid rate depending on which direction I am pushing it. I think that rapid movement of the top link while the blower is going is contributing to the breaking of the shear pins. So for now, I am training myself that if I want to move the blower up or down; or in or out, I need to turn down the rpms, and disengage the pto FIRST, and THEN move the positioning. I think that will work for now.