Operating 3 point blower in raised position- why not?

[Reb954]

My manual for my snowblower says not to operate the blower with the PTO shaft at more then 15 degrees as it could damage something or cause shear bolts to break. I have not measured the angle with my blower raised all the way, guess I need to do that.

I can see where that would cause problems with the driveline U-joints but I'm not sure I see how it would cause shear bolts to break. Maybe it depends on how the driveline shear bolt is setup.

 

[CobyRupert]

My manual for my snowblower says not to operate the blower with the PTO shaft at more then 15 degrees as it could damage something or cause shear bolts to break. I have not measured the angle with my blower raised all the way, guess I need to do that.

Also measure it when it’s all the way lowered, and at that spot where you snowblow and start to back over the bank/ditch and the snowblower drops down another 12”.

(Or where you snowblow up a hill and the blower breaks over the top of the slope first, etc.. This happened to me couple days ago with logging winch. Tractor parked facing downhill on steep bank, set winch down on level top of bank. Looked like a 45 degree plus angle on the PTO shaft. Time to reset. )

 

[hube2]

I can see where that would cause problems with the driveline U-joints but I'm not sure I see how it would cause shear bolts to break. Maybe it depends on how the driveline shear bolt is setup.

Not sure I understand why that would happen either, my shear bolt is located between the joint and the blower's gear box. There should not be any wobble at that location. Are there PTO shafts that have shear bolts between the joints?

 

[FatTire]

Not sure I understand why that would happen either, my shear bolt is located between the joint and the blower's gear box. There should not be any wobble at that location. Are there PTO shafts that have shear bolts between the joints?

Yes- my Meteor 3 pt. blower has a shear bolt in the PTO shaft. I've broken that one once, and the "normal" one on the gear box output shaft about 6 or 7 times. (I have a lot of rock around my place.)

 

[FatTire]

+1 on the unimog pics

These might already be posted in the Snow Weapons photo thread, but it would be 400+ pages back.

 

[Industrial Toys]

Thanks. So there are two Engines in that thing? What are they? Both Liquid cooled? How much snow will that thing drive through (generally speaking)?

 

[FatTire]

Thanks. So there are two Engines in that thing? What are they? Both Liquid cooled? How much snow will that thing drive through (generally speaking)?

Correct, the truck has a small gas engine, the blower is powered by a 110hp turbo diesel, both liquid cooled. They both have a port in the cooling system where you can insert a gasoline fired heater called a "swingfire". The idea is that you can warm the engines without access to AC power for a block heater. Similar to a modern Espar heater but crude by comparison. With "normal" snow (i.e. soft enough that you sink in to your knees when you walk on it) it will clear a path through 40 inches of snow. For wind-drifted snow that is stiff enough to drive on top of with a tractor (until you break through) it will break through about 30 inches, slowly. Here is a video of crawling through very hard snow about 2 feet deep-- notice my friends walking around on top of it.

And sorry for the thread drift -- the Unimog blower cannot be operated more than about 3 or 4 inches off the packed surface due to drive-line vibration. Maybe when it was new that wasn't so much of a problem. The PTO looks ok but it is almost 60 years old.

 

[leonz]

I wish I had 3 AEBI Schmidt 1600S railway snow clearers (formerly the Bielhack HB1600S model),
I would be able to make a lot of money from plowing snow on the the western railroads every year.

 

[PILOON]

There is less chances of sheer bold damage if you leave the blower engaged while driving.
Every time U engage your blower you create a mild shock load.
Also while elevated most blowers would have the U joints closer to straight line, it is high angles that create rapid U joint wear.

Having watched professional snow contractors often I rarely see them not spinning as they go from drive to drive.
Besides, time is money and to engage/disengage at every drive would cost.

 

[hube2]

.... Also while elevated most blowers would have the U joints closer to straight line, it is high angles that create rapid U joint wear...

When my blower is on the ground the PTO shaft is nearly level and in a straight line, maybe a very slight downward angle to the blower, the greatest angle I'll see is when it's raised all the way. So this really depends on the tractor and blower.

If the angle when raised is large I would rather take a chance on breaking a few shear bolts by stopping and starting than to risk damaging the U joints.

I still need to measure the angles, I have ordered a digital level. Until I'm sure I will be careful not to lift it very high while the PTO is running.