PTO Jams causing tractor to stall

[rookiejeff]

Hello all:

I have a 2010 Kubota B3300 with a 64" rear PTO snowblower. On at least 3 occasions now I have hit a large stick buried under the snow that jams the impeller causing the whole tractor/engine to IMMEDIATELY shut down. I mentioned it to the dealer once, concerned about damage to the transmission/ PTO and they didn't seem terribly concerned as long as it doesn't happen too often. To me, it seems like a really bad thing to have a PTO shaft cranking at about 500 rpms and an engine moving at 2000 rpms to instantly cease because of a jammed implement. No? Am I causing serious damage to the tractor and is there some adjustments that need to be made? I thought that was the whole reason for shear bolts; to break when under severe load to prevent undue stress on the tractor and PTO. It is a rather large blower, perhaps "weaker" shear bolts should be installed given the lower HP (33) of the tractor? Any input would be much appreciated. Thanks!

 

[North Idaho Wolfman]

Yes you can compensate for a lower HP by weakening the shear pins.
Just cut the pins partially.
Another not so cheap option is to add a slip clutch if your really worried it.

 

[Dave_eng]

I am with you on not wanting a sudden jolt stop. No machinery is designed for this other than the table saw that stops when you feed it a hot dog or your finger http://www.orangetractortalks.com/forums/images/icons/icon12.gif
Please provide more info on the shear bolts. There should be one on the pto shaft and another on the drive to the auger(s).
Bolt diameter and a photo of the markings on the head of the bolts so we can see what grade/strength you are using.
Dave M7040

 

[North Idaho Wolfman]

other than the table saw that stops when you feed it a hot dog or your finger

Being in the wood game, That is one sweet safety feature!
http://www.sawstop.com/

 

[Daren Todd]

I cringe whenever I see a something like that. cause you know some idiots gonna get a few beers in them and start demoing that feature with there hand

 

[olthumpa]

An acquaintance of mine could have used one of these 30+ years ago when he cut off 3 fingers at once.

 

[Kennyd4110]

Grade 2 or 5 shear bolts are the norm, do you know what grade you have installed now?

 

[res]

I can say I would be concerned about sudden stops and shear pins not breaking.
For the record, if I am not mistaken, even the saw stop jams a piece of aluminum into the blade to stop it on a dime. Damage is done. Often the blade is ruined or will need a tooth or two welded back on. That is why it is a safety feature. From the Sawstop FAQ section

Can the blade be reused if the safety system brake is activated?
When the safety system activates, it will often damage one to two teeth on the blade. It is usually cost-effective to have high-quality blades repaired by a qualified blade sharpening service. However, less expensive blades should be discarded.

Back to the OP, I like the advice to reconsider what pins you are using. Seems to me they are just to strong for your HP.

 

[rookiejeff]

Thanks every one for the responses. I'm not sure what bolts I have, but I'll take a look the next time I'm at camp and let you know.

Jeff

 

[MHTRAPPER]

My dealer told me and so did the people at meteor grade 2 if you cant find grade 2 you can use grade 5 until you can come up with grade 2. I don't think the grade 5 would stand up if you had a warranty issue even though they told this. I had to order mine online. Good luck.

 

[BAP]

Tractor Supply carries Grade #2 bolts in their hardware isle, or least the one near me does. In their loose bulk bolt supply they carry Grade 2,5,and 8.

 

[ShaunRH]

My dealer told me and so did the people at meteor grade 2 if you cant find grade 2 you can use grade 5 until you can come up with grade 2. I don't think the grade 5 would stand up if you had a warranty issue even though they told this. I had to order mine online. Good luck.

The grade 2 sheer pin on my RCR 1260 has taken a ton of abuse, beyond what I felt it should but it's still there. I don't think I'd mess with grade 5. If you can't find a grade 2, keep looking, any tractor dealer should have them.