Rear Blade Bent pins

Tvanharp · Mar 11, 2012

I have a 72" Tarter blade on my Kubota L4330. Currently the large pivot pin, about 1 1/2" dia, is bent and I've gone through 3 ,3/4" adjustment pins. Also the adjustment holes have been elongated due to the bending of the adjustment pins. I've ordered a new assembly to replace the damaged parts ($200). I keep catching rocks or a hidden stump in one case that is causing this damage. With the new parts on their way I need to come up with a way to prevent this. Any ideas? Thanks.

2458n · Mar 11, 2012

Slow down.

Tvanharp · Mar 11, 2012

Oh thanks, never thought of that.

BelarusBulldog · Mar 11, 2012

Not familiar with your brand of BB, but could it be that it is too slight for your tractor? You never mentioned what grade it was, so I wonder if that maybe your trouble. For the main 1 1/2" pin to buckle and the holes to be worn oblong, the blade is being pushed over its' limit, somehow!

Tvanharp · Mar 11, 2012

Not sure the grade, it was called heavy duty. Was included with the tractor. The time that it bent the big pin the leading edge (running at an angle) caught a stump sticking up about 2 inches (was under the snow) running at a very low speed but by the time I felt it, it was too late damage was done. Was thinking more along the lines of a sheer pin or some type of release mechanism, springs, something like that....

BelarusBulldog · Mar 11, 2012

If it's classified as HD, then I wonder if there's not a problem with the steel used? It takes a lot of force to bend a 1 1/2" pin and with the blade set at an angle, one would think that it would just move the whole unit (tractor and blade) sideways! Have you complained to the dealer or manufacturer, what do they say?

greg_g · Mar 11, 2012

Here's a photo of a 72" Tartar. Pretty sure I know what you mean by pivot pin, that's what I call the one in the middle that lets the blade index right and left. But what is an "adjustment pin"? Is that what holds the blade at a specific angle? If not, can you point it out on the photo? And are you pushing or pulling when you've bent these pins?

//greg//

Tvanharp · Mar 11, 2012

Yep that's the blade. The pivot pin is the big one with the nut. The adjustment pin is the one used to change the angle.
Was pulling when it happened. Right now I can't swing the blade around because the adjustment plate hits the main support arm as it rotates. You can how the plate is at an angle to the main support this is because that big bolt is bent. The big bolt and adjustment plate is all one welded unit. That is what I'm replacing.

BelarusBulldog · Mar 11, 2012

Wow, that doesn't look good! If you are replacing everything that is bent with new, then this is what I would do to make everything stronger. Everything in blue is your blade now, what I would do to make everything stronger is in yellow and would need to be welded on. Hope this helps. :thumbsup:

rambler · Mar 11, 2012

Really the 2 options are a heavier duty blade built better, or drive slower.

Don't know of any spring/release setups for a back blade.

Something has to give. Either your wheels spin, or something bends. The blade needs to be built heavy enough to handle the shock loads of the speed you are moving.

If it busts up, you are moving too fast for that blade.

--->Paul