Tiller better sheer bolts for reversing tiller

[taborekle]

Hi all,

Pretty new to tractoring and tillering.

When the dealer dropped off my B2920 and RTR050 tiller, he showed me the shear bolt location on the tiller and gave me two spares, with the admonition not to go to a harder bolt.

After shearing 2 of the 3 bolts, I took the last bolt to my local True Value and found a -close- match. A 3mm (pretty sure) 8.8 metric bolt. The only difference is that its solid threads after the bolt head, while the origional bolt was half solid shaft before going threads.

I bought a dozen of these replacement bolts.

We'll, I've been shearing them left and right. 15 minutes tillering, hit a rock, shear bolt, 5 minutes to replace, then 15 minutes tillering, hit a rock, etc. My brother in law says I need a 'harder bolt', but because of the Kubota dealers caution, I'm reluctent to do so.

I'm thinking that since the replcements are solid threaded, that their not as tough in shear as the origional's that were solid shaft through the shear point.

Anyone have any experience in this? Any suggestions other then to find 3mm grade 8.0 metric mostly solid shaft bolts?

Larry

 

[phyxer]

I don't think I'd go to "harder" bolts if it were me. Any possibility of "de-rocking" the ground before you till? If not I'd say that replacing bolts is MUCH cheaper than replacing parts on the tiller or tractor! Good Luck and let us know how it turns out!

Troy

 

[Farmwithjunk]

Purchase (and install) a slip clutch.

 

[flusher]

Hi all,

Pretty new to tractoring and tillering.

When the dealer dropped off my B2920 and RTR050 tiller, he showed me the shear bolt location on the tiller and gave me two spares, with the admonition not to go to a harder bolt.

After shearing 2 of the 3 bolts, I took the last bolt to my local True Value and found a -close- match. A 3mm (pretty sure) 8.8 metric bolt. The only difference is that its solid threads after the bolt head, while the origional bolt was half solid shaft before going threads.

I bought a dozen of these replacement bolts.

We'll, I've been shearing them left and right. 15 minutes tillering, hit a rock, shear bolt, 5 minutes to replace, then 15 minutes tillering, hit a rock, etc. My brother in law says I need a 'harder bolt', but because of the Kubota dealers caution, I'm reluctent to do so.

I'm thinking that since the replcements are solid threaded, that their not as tough in shear as the origional's that were solid shaft through the shear point.

Anyone have any experience in this? Any suggestions other then to find 3mm grade 8.0 metric mostly solid shaft bolts?

Larry

Farmwithjunk is correct. Get a slip clutch for your tiller. Here's mine.

That's my old Kubota B7510HST with a Yanmar RS1200 tiller (48" wide). The slip clutch is the yellow things with the springs in the 2nd photo. Cost about $130 at Tractor Supply.

Tractor Supply Company - PTO Slip Clutch, 1-3/8 in. 6 in. Spline Shaft

 

[Stimw]

If you want to go to the slip clutch Agri- supply has them in the $80. range. They are plug and play, Male spline one end, female splin on the other.

 

[Skyco]

If you want to go to the slip clutch Agri- supply has them in the $80. range. They are plug and play, Male spline one end, female splin on the other.

Well not exactly plug and play since frequently the PTO shaft has to be shortened
BTW I second AgriSupply, same exact slip clutch as Tractor Supply- $50 less...talk about mark up

And yes the fully threaded bolts are weaker in shear than the originals, assuming same grade steel etc. it is probably metric grade 8.8, roughly equivalent to grade 5 standard bolts, 3mm sounds awfully small too...