Snowblower Proper way to connect PTO shaft to snowblower?

[jim_wilson]

A few weeks back I managed to score a 54" Loftness snowblower for my BX23. The snowblower was originally setup to be attached to a Ransomes golf course snowblower so it did not have a PTO shaft or the proper 3pt attachment setup to hookup to the tractor. Not having a shop to work in I had to wait until the weather got a little better to be able to do the welding to get the 3pt setup put together but I now have that done and am trying to figure out how to get the PTO shaft hooked up to the blower - properly.

I already bought a PTO shaft and got the correct knuckle to adapt the shaft onto the gearbox on the blower. The shaft that I got has knuckles on each end that are splined - the first problem I have is that the shaft coming out of the front of the gearbox on the snowblower is a straight, smooth shaft with a keyway and one hole crossdrilled thru it. So the first thing I have to do is swap the proper knuckle on one end of the PTO shaft so that it will fit properly onto the smooth shaft coming out of the snowblower gearbox. That is pretty straightforward and just involves separating the U-joint to take the splined knuckle off the PTO shaft and reassembling it with the new smooth bore knuckle - not a problem there.

However I am not sure how exactly I am supposed to tie the new smooth bore knuckle into the smooth shaft coming out of the snowblower gearbox. There is a keyway and I have some key stock but one of the guys I work with said that one of the shear bolts for the blower should be located where the PTO shaft meets the gearbox - I am assuming that if the 2nd stage impeller gets jammed it will break the shear bolt. The parts guy at the tractor dealer said to get a Grade 3 bolt and put that thru the knuckle and the crossdrilled hole in the gearbox shaft. So does the bolt act as the shear pin?

Did I maybe get the wrong PTO shaft for this blower? I did some searching on the web and found a manual for a Buhler snowblower and the parts breakout in the manual showed an entirely different type of end on the PTO shaft than what I have. In the Buhler breakout the blower end of the PTO shaft has a flat plate with two bolts that is described as the "shear assembly". Should I maybe just call Loftness and get the proper PTO shaft for this blower?

 

[beenthere]

From what you describe, the bolt is the shear bolt, and is as you suspect, the 'breaking' point if something gets stuck in the blower.
I'd look for what keeps the PTO shaft from falling off the smooth shaft if the shear bolt 'shears', as you want it to just run free but not fall down and flop around while you are disengaging the PTO.

Calling the mfg would be a good bet, unless you find someone to look at it and can set you straight. You don't want to tear it up right off the get-go.

 

[DaMadman]

One Word


PICTURES /forums/images/graemlins/grin.gif

 

[hazmat]

Jim,

You're welcome to stop by and see how my ancient Ford unit is put together in person...

If the shaft has a keyway, that is not usually the location for a shear bolt. The shear bolt will either go thru two concentric tubes on the PTO shaft or will be on the impeller somewhere. On my Ford unit, the shear bolt is on the impeller - if the shear bolt breaks, the shaft continues to spin, but the impeller is idle.

Having proper shear bolt protection is important for a snowblower, plenty of hidden surprises. /forums/images/graemlins/shocked.gif A slip clutch would be overkill, but may be easier to "engineer" Don't know how it would hold up to the winter environment...

 

[jim_wilson]

Thanks for the offer to look at your blower - if I can't figure this out I may take you up on it /forums/images/graemlins/smile.gif . I did some searching on the web and found a manual for a Buhler blower and the PTO shaft blowup diagram showed a double shear bolt configuration on a plate on the shaft. I ended up sending an email to the Loftness parts department and they responded that they can get me the proper shaft for the blower so I think I will probably go that route since that should guarantee the proper configuration.