Stripped Woods RBS72P Rear Blade Moldboard Clamp

[SManZ350]

I have a Yanmar rear blade (rebranded Woods RBS72P). Earlier this week one of the two bolts that holds the balde to the frame sheared and that allowed the other one to rip the threads out of the clamp. The threads are in two square nuts that are welded to the clamp. These two bolts look to me to be a weak point, especially when the blade is offset.

It is Part 4 in the diagram and I tried to order a replacement through Messicks and they told me the part is on backorder and haven't yet given me an ETA. So I'm meeting with a friend that can weld tomorrow to try and fix this. We plan to grind off the two square nuts and put two stacked grade 8 nuts in their place. We'll have to stack the two nuts carefully so that the bolt can thread through both smoothly. I figure that the extra thread will allow the grade 5 mounting bolts to shear without damaging the threads on the mounting nuts. The original mounting bolts were grade 5 but I don't know what the original square nuts were made out of.

What do you all think? Any other suggestions? Should I use a grade 2 mounting bolt or would this not have enough strength to mount the blade and keep it in place?

Thanks!

 

[patchnball]

I welded two single grade 8 lock nuts to mine. I have not liked the system since new. A poor design on Woods part as far as I am concerned. Wish I would have saved my monies.

 

[Zebrafive]

You might try Union nuts, instead of stacking. Can you go to larger diameter bolt ? I can't tell how much room you have with the slot for a bigger bolt. Switching to fine thread bolt and nut will give you little more strength for the same size.