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.

 

[aczlan]

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

If you have threads in the shear area, you have the wrong bolt in there.
If you need the added clamping force, sure but otherwise, not so much.

Aaron Z

 

[CobyRupert]

"If snow is packing into the blower - you are going too fast OR the snow is too wet or a little of both. "

What I did this year is to form a HD plastic liner for my chute and it worked fine, no clogging after the first season snowfall.
Now today we have4 inches of 'snowman' snow so it will be a real test.

What I've found with wet snow is that:
Yes,, too fast will clog, but you can usually hear the load (motor) bog down first.
Also going too slow will result in not enough snow passing through that sort of "self-cleans" the chute. That is, little spurts of snow that aren't being pushed out by "more snow" pack here and there, restricting the flow and eventually clog.

There is a sweet spot.

Also paint, wax, fluid film, silicone, Pam cooking oil, etc...anything that keeps it slippery helps a lot.

 

[Captain Dirty]

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

From an engineering standpoint given the same grade of steel, an unthreaded rod is stronger than a fine threaded rod is stronger than a coarse threaded rod as the depth of the threading reduces the cross section. Given that the purpose of a shear bolt is to fail before something more expensive is broken, I'll take the weaker, coarse threaded bolt (and maybe have to change shear bolts more often).

From a practical standpoint, I doubt the calculation of shear bolt size is more precise than the inequality that the shear bolt breaks first, and I seriously doubt the friction between the flanges is considered. Who, kneeling in the snow in often inclement weather, uses a torque wrench when replacing a shear bolt? TAR (That's about right) works for me. My snow blower manufacturer specs grade 5, 1/4-20 x 1 and 1/4-20 x 1-1/2 shear bolts. The shorter bolts are fully threaded, and the longer bolts have a shank that barely intersects the plane between the flanges. Also, 1/4-20 and 1/4-28 are standard, readily available sizes; albeit the coarse bolts and locknuts are more common and a little cheaper. You will not find a 1/4-18 bolt.

Evident in comment #6 and later reinforced by the OP in comment #13 is that Woodmaxx has discrepancies indicating a lack of attention to detail. What other shortcomings or defects may have slipped by quality control?

 

[PILOON]

What I've found with wet snow is that:
Yes,, too fast will clog, but you can usually hear the load (motor) bog down first.
Also going too slow will result in not enough snow passing through that sort of "self-cleans" the chute. That is, little spurts of snow that aren't being pushed out by "more snow" pack here and there, restricting the flow and eventually clog.

There is a sweet spot.

Also paint, wax, fluid film, silicone, Pam cooking oil, etc...anything that keeps it slippery helps a lot.

Yes, and that's why I heat formed a HD plastic liner for my chute and can report it works as well as I had hoped.

Can also say that come spring rattle can spraying the chute to prevent rusty surface also helps a lot, but the plastic liner is still best.

 

[JerryK]

Several more points about shear bolts. They should be put in snug, but not so tight to pre-stress the bolt. Like mentioned above, there should be little or no threads in the bolt that will elongate the holes over time. You should try to engage your PTO at low RPM's, you can stress or even break the shear bolt by just the jolt of getting it to turn. Especially with new ' tight ' blowers. Some tractors do not have hydraulic clutches with a built in accumulators [ a small tank like devise to slow down the engagement process ] to take the shock out of the engagement.

 

[cdaigle430]

do you the have the impeller re-stricter plate on yours like I have on my 60 inch? You may be packing to much volume from the auger to the chute. These Woodmaxx snowblowers are heavy duty...impeller alone is half an inch thick. Also they are optimaly engineered to run at the 540 rpm range...

 

[MAN IN BLACK]

From my experience, speed is not your best friend with a snowblower.
You have to go slow to give it time to swallow everything.
Each time I break one, most if the time I am going to fast in reverse

 

[jpm]

Mine is when it tries to eat big rocks ,

 

[Quebecguy]

Having the drive chain on your blower too loose can cause broken shear bolts too. Guess how I know!

 

[Industrial Toys]

I find it amazing what size stones you can blow!

Ground is not frozen here and I have dug in a good half foot into top soil in places.

At least my waterline shouldn't freeze this year.