Snow Attachments more snow blower pto questions

[jimb1724]

thank you all for the replies to my last post on this subject.... but i am still confused...

after talking to provonst direct and several dealers i am more confused about the pto driveline set up i need for a puma blower...

here's what i know.... tractor side standard 1 3/8" 6 spline blower side is 1" shaft with keygate (1/4 by 1/4 by 1 5/8") and a hole for a 6m x 40 bolt......

here's my question.... is the 6m x 40 bolt the shear point for the the pto drivetrain ? if so, what is the purpose of the key ? if not, where are the shear pins located ?

i was told that since it is "keyed" this is not a shear point and there must be shear pins in the auger and impleler on the blower itself..... i have looked all over the blower and do not see anything that resembles a shear pin.... just a couple of grease fittings at either end of the auger...

i am going to try to talk to the manufacturer again next week but would appreciate some input from you guys.....

thanks for all of your help and input....

jim

 

[6sunset6]

I have that exact same snowblower. On the tractor end of the PTO shaft there is a shear bolt that pins the end of the PTO to the assembly that slids over the PTO shaft on the tractor. It came with a 1/4 bolt or some metric equivelent . It sheared all the time in the middle of a snow storm. I drilled out to 5/16. Has not sheared since. That was a long time ago.
Probably a big no no but it has to work.

 

[hayden]

My older snow blower (not a Puma) had two sheer bolts. One was part of the yoke on the tractor end of the drive shaft just as 6sunset6 describes. That protects the driveshaft, gearbox, and impeller. The second bolt was part of the coupling for the side-to-side drive shaft that powers the auger. This shaft had a cover/shield over the top, but you could get at it from underneath. It runs from the gear box to the chain drive on the end of the unit. On mine, the sheer bolt was at the gearbox end of the shaft.

90% of the time I'd pick up a rock and it would wedge the auger and break that bolt. Only once or twice did I pop the main driveshaft bolt.

 

[rbargeron]

here's my question.... is the 6m x 40 bolt the shear point for the the pto drivetrain ? if so, what is the purpose of the key ? if not, where are the shear pins located ?

The key is not a shear device - it is the main torque driver - it has a set screw to keep the key in place. There is also a small thru-bolt whose purpose is to keep the joint from working itself apart lengthwise during operation. Torque protection is not always provided in a pto driveline - but can be in the form of a slip clutch, or a small bolt (1/4 or 5/16) through two flanges at the tractor end, or may me a larger (1/2") shear bolt through the u-joint and shaft at the implement end.

On snowblowers the gearbox may be direct-thru drive to the impeller so it may not be provided with a shear bolt - but it is common for the gears to be protected by a shear device on the auger drive somewhere - look for a shear bolt at a coupling or at the smaller sprocket.

 

[jimg]

I have that exact same snowblower. On the tractor end of the PTO shaft there is a shear bolt that pins the end of the PTO to the assembly that slids over the PTO shaft on the tractor. It came with a 1/4 bolt or some metric equivelent . It sheared all the time in the middle of a snow storm. I drilled out to 5/16. Has not sheared since. That was a long time ago.
Probably a big no no but it has to work.

Ditto...this is how mine was set up. I never altered it b/c the bolt never had occassion to shear. Still have a handful of bolts that came w/ the blower which I passed along to the buyer.

 

[jimb1724]

thanks for the input....

after working with a local dealer parts dept, i am going with the manufacturer's part although more expensive.... $260 vs. $120- $140... turns out to be quite a bit different....
at the end of the day it's better to go with the original as engineered by the manufacturer.....
it has been quite a learning experience ...... for a guy who thought pto shafts were pretty much standard.....

 

[jimg]

The shaft on my machine was a Comer. Is that what you wound up w/?

 

[George2615]

thank you all for the replies to my last post on this subject.... but i am still confused...

after talking to provonst direct and several dealers i am more confused about the pto driveline set up i need for a puma blower...

here's what i know.... tractor side standard 1 3/8" 6 spline blower side is 1" shaft with keygate (1/4 by 1/4 by 1 5/8") and a hole for a 6m x 40 bolt......

here's my question.... is the 6m x 40 bolt the shear point for the the pto drivetrain ? if so, what is the purpose of the key ? if not, where are the shear pins located ?

i was told that since it is "keyed" this is not a shear point and there must be shear pins in the auger and impleler on the blower itself..... i have looked all over the blower and do not see anything that resembles a shear pin.... just a couple of grease fittings at either end of the auger...

i am going to try to talk to the manufacturer again next week but would appreciate some input from you guys.....

thanks for all of your help and input....

jim

I have the puma 64. I posted some PTO shaft end pics before, maybe it wasn't for you but someone else. The blower end of the PTO shaft slides on the keyed shaft and is held in place with a bolt and nut. It is not a shear bolt and simply holds the back end of the PTO shaft to the blower.
One shear bolt is located on the PTO shaft end that attaches to the tractor. A second shear bolt is on the blower shaft almost to the where the chain goes on the smaller sprocket behind the guard plate. Look for it and you'll see it. You'll need a few extra shear bolts. I go through about a dozen or so a season.