Snow Blower Frustration!

[RidgeHiker]

That can be one cause. Does the tractor have an electro hydraulic PTO or standard PTO? At full RPMs the electro hydraulic PTO will gradually start the PTO shaft, but a standard PTO will jerk that PTO shaft to start at full RPMs; this will weaken and break the shear pins on the PTO shaft. A lot people do not realize this, so if you do not know the type of PTO you have, turn PTO on at low RPMs and then rev up to full full RPMs and then attack the snow. For wet snow, as others have stated, go as slow as possible so you do not clog the chute. Worst case spay the chute and fan with fluid film or some kind of oil; even PAM will work. Good luck!

Interesting. I assume I have a standard mechanically driven PTO. The switch is electric. When it starts it appears to go to speed quickly. I'm one of the the "do not realize this" ones. Thanks for the tip on keeping the rpm lower initially. Have not broken any shear pins at startup but certainly could be stressing them.

Did some more blowing. Have been more careful what I am pushing it into and have not had a problem. Still working on adjusting the tilt vs keeping the shaft away from the quick hitch structure which meant tilting it back further than I like and was picking up a fair amount of dirt. Packed around the auger tightly but still did fine. Did some more resetting mounting onto 3 point and I think I have it set better but I will know more next time I run it. Been thinking about not using the quick hitch and getting telescoping lower lift arms but seem pretty expensive. With the blower weighing 755 lbs need something to replace quick hitch. Could get Pat's system but would also prefer not to push attachments back extra distance though a little less than my 3 point quick hitch.

 

[OrangeMuscle]

What should the rpm be when engaging PTO? Makes sense to keep it low to engage then gradually increase. Is there such thing as the RPM's being too low when engaging?

 

[leonz]

Hello Orangemuscle,

The engagement speed for the rear power take off should be just above the idle engine speed of your tractor.

This reduces the shock loading on the tractors power take off and the propeller shaft to the gearbox of your snow blower.

 

[seville009]

What should the rpm be when engaging PTO? Makes sense to keep it low to engage then gradually increase. Is there such thing as the RPM's being too low when engaging?

Basically, as low as possible, and then ramp it up once itç—´ engaged.

Sometimes if the rpms are too low, it might not engage

 

[ruffdog]

What should the rpm be when engaging PTO? Makes sense to keep it low to engage then gradually increase. Is there such thing as the RPM's being too low when engaging?

Each tractor is different....find the sweet spot for yours.

 

[Fallon]

What should the rpm be when engaging PTO? Makes sense to keep it low to engage then gradually increase. Is there such thing as the RPM's being too low when engaging?

If your tractor stalls when engaging an impliment your RPMs are to low. It's mostly as simple as that for an electronically activated PTO. You can engage the clutch a bit smoother (or not) if it uses manual clutch. The smoother you engage the clutch the less shock load on the PTO shaft, sheer pins & what not. But at the expense of clutch life. The less RPMs the engine is turning, the less shock load & clutch wear for any PTO system.

Some electro hydraulic units do a soft start, others are much more abrupt, all depending on OEM design. The OP mentioned switch so its electro hydraulic. As a reference some PTOs are engaged by a lever actuating a PTO clutch. Others have a small lever that usually actuates a cable to engage the PTO gears directly & you need to use the transmission clutch to stop power before engaging, then let the clutch out to spin things up. Those 2 designs are entirely dependent on how you operate those manual clutches as to how smooth or snappy the PTO starts up.

The other factor is the impliment. My tiller puts no load on the tractor at all if it's in the air. Low rotating mass & favorable gearing as it spins slow. My flail mower on the other hand really lugs the tractor. Heavy drum & hammers with a high rotating speed. I need a few extra RPMs for the flail to not stall when I spin it up. I have to check to see if the tiller is even hooked up or spinning when I hit the PTO switch as there is no noise from it or any grunts from the engine at an idle.

 

[milkie62]

I just went back and enlarged aczian's attachment (comment #3). On page 24 the caption on the lower left picture states there are six 1/4" holes in the flanges on the augers. The "note" states the machine comes with two M6 grade 8.8 bolts [116000 psi so grade 5 (120000 psi) for practical purposes] but these may be substituted with two or three "1/4" x 18 x 1-1/2" bolts". One-quarter inch = 6.3 mm so grade 5 1/4" bolts would be stronger than grade 8.8 M6 bolts; 3 of them would obviously be stronger than the 2 original bolts. SAE 1/4" bolts are usually 20 TPI (coarse) or 28 TPI (fine); 5/16" bolts are 18 TPI (coarse). This may be a typo, but that and the lack of a grade spec for the substitution gives me pause. You might e-mail Woodmax for confirmation and to have something in hand if there is a warranty issue.

Why would it matter what TPI it was anyway since the threaded part is outside of the shear part ?

 

[wheelbuilder]

Why would it matter what TPI it was anyway since the threaded part is outside of the shear part ?

I'm curious too, my snowblower (Allied) manual calls for fine pitch on the PTO shear bolts as well.

 

[aczlan]

Why would it matter what TPI it was anyway since the threaded part is outside of the shear part ?

If it's 2 flanges that bolt together, a fine thread bolt will pull them together tighter for the same amount of torque tightening the bolt which will give you more friction between the two flanges.

Aaron Z

 

[shooterdon]

Why would it matter what TPI it was anyway since the threaded part is outside of the shear part ?

Fine threads will have more strength due to the larger minor diameter.

On the 3/8 shear bolts on my blower, than results in just over 13% more shear strength.