Rotary Cutter Shear Bolt and Slip Clutch

[wcampbell47]

This is very similar to the slip clutch on my rototiller. The PTO shaft has splines and the bolt is used to keep the PTO shaft from slipping off the splines on the slip clutch. The nut came off the bolt and the bolt came out on my unit. Eventually the PTO shaft slid off the slip clutch splines. Fortunately I caught it in time to prevent any damage.

 

[Baby Grand]

If the shaft is splined, it matters not where the bolt passes, it is NOT a shearbolt. The yoke can't rotate freely on the shaft if both are splined. :confused2::confused2:

Doh! So true.

 

[MHarryE]

If it were intended to be a shear pin, what holds the u-joint yoke on the shaft if the bolt shears. My Land Pride has a slip clutch but the book says on the shear bolt version there is a snap ring to hold the shaft in place in case the bolt shears. Think of it - with nothing to retain the spinning shaft, it could pull off the gearbox and you would have a PTO shaft whipping around in the air. Does the other side of the shaft, not shown in the picture, have a keyway? Not all gearbox input shafts are splined. It could be a shaft with key and cross bolt. My King Kutter RFM has a shear bolt but also has a snap ring to retain the shaft if the bolt shears.

 

[Willl]

I'm going to say that's a 'retainer' bolt also. Not a shear bolt.

 

[greg_g]

I'm going to say that's a 'retainer' bolt also. Not a shear bolt.

If it's a splined shaft, definitely. Grade doesn't matter either. If it's a smooth shaft, it depends upon the grade of bolt. OR - perhaps a neglected slip clutch froze up on a smooth shaft, and the owner elected to put in a shear bolt rather than clean up the clutch.

//greg//

 

[hydro2]

I will check to see if it is splined. Thanks for all the input!!!!

 

[Willl]

"splined",,,, I'm going to put my money on 'keyway'.

 

[hydro2]

I think you are right!!!!!

 

[hydro2]

I know the slip clutches are better, but I was hoping for a shear pin. It would have saved me messing with the slip clutch.

 

[greg_g]

I know the slip clutches are better, but I was hoping for a shear pin. It would have saved me messing with the slip clutch.

That might be what the original owner thought too.

//greg//