Bending my box blade hitch, please help!

[chris the wrench]

Kubota L3902, land pride box blade(1572).

I'm bending the hitch assembly on the box blade where the lift arms attach. Both sides are bowing to the outsides. Hopefully these photos communicate what's going on.

What am I doing wrong??? Quickhitches not adjusted to the correct angle, so they want to slide out?

For repair I'm thinking I'll bend them back to the correct shape with a press, and then weld some 1/4" flat stock across part of the top to 'box' in where I can, but that doesn't help with what did I do wrong??

 

[Piston]

It appears you need to properly set your sway bar adjusters. Are they screw type? It's hard to tell from the pics, but you should be able to adjust them so there is no outward pull on the swaybars.

 

[CliffordK]

My guess is that you're turning with it under load. But, the thing can't possibly be designed such that turning would be unexpected.

Is there a HP rating on the blade?

I'd probably complain mightily to Kubota. Then take say a 3x3x(1/2)" angle iron and weld it to the outside of those bars.

 

[MtnViewRanch]

I agree with Piston. Adjust the sway links so that the Pat's QH ends are centered on the pins.

This will then allow for some side-side movement.

 

[chris the wrench]

It appears you need to properly set your sway bar adjusters. Are they screw type? It's hard to tell from the pics, but you should be able to adjust them so there is no outward pull on the swaybars.

They are the threaded type. I always thought they were designed to be pulled against(tension), not pushed against(compressed). Im not saying you're wrong, Im just having a hard time understanding how that would help?

Is there a HP rating on the blade?

17-40, and Im at 39.

Adjust the sway links so that the Pat's QH ends are centered on the pins.

This will then allow for some side-side movement.

Alrighty, I like when there is some consensus. I'll give this a try. So I will be lengthening them to 'push' them more to the center of the tractor and the pins.

 

[Chanceywd]

If you don't want to weld, maybe after bending the bars back some 7/8 shaft collars and or washers on the outside of pins so the bars can't deflect easily? That way instead of welding the space would be defined and stress would be on both the inner and outer bars.

 

[old and tired]

Hard to see with the photos (one is too close and the other too far away). Are they bent to the outside? Did you push or drive backwards?

It's design to be pulled forward only....

 

[CliffordK]

If you don't want to weld, maybe after bending the bars back some 7/8 shaft collars and or washers on the outside of pins so the bars can't deflect easily? That way instead of welding the space would be defined and stress would be on both the inner and outer bars.

I thought about using the lynch pins tight up against the bars (or with washers to hold them in place). I thought that it could get stuck. But, perhaps neither bar would exceed normal elasticity, and one would be OK. Anyway, it is worth trying.

 

[ruffdog]

If you don't want to weld, maybe after bending the bars back some 7/8 shaft collars and or washers on the outside of pins so the bars can't deflect easily? That way instead of welding the space would be defined and stress would be on both the inner and outer bars.

Agree^^^ Get pins that are short enough and washers so the outside plate gets some support from the inner one too.

 

[workinonit]

I'm guessing you bent those pushing material backward. The ones on my Hardee are bent like that and it had nothing to do with the sway bars. I adjust my sway bars so there's just a bit of side to side so I don't bind things up. One thing you could do after you get things straight is get some bushing cut so that it keeps the arms centered. I never really pay either of mine much attention.

 

[Jrasband]

There are a few ways you could beef that up through welding. Replace the bent plate with something much thicker, or add another plate in addition after bending back, Extend the bottom horizontal plate closer to the pin, add a horizontal plate to the top, put a gusset on the bottom of that outer plate underneath the pin.

 

[DarkBlack]

That bend is caused by that connection being forced forwards into your tractor’s upper link.

Your scarifiers are on the front leading edge of your box blade.
When you hit something substantial underground with them, like a rock, or roots, the rearward force on the scarifiers pushes rearward on your lower links, and the force causes the upper box blade to try and rotate, forward, pushing on your upper link, causing it to bend.

If you don’t want to weld the two sides together, you could add tight fitting spacers to the sides of your upper link.

 

[LittleBittyBigJohn]

They are the threaded type. I always thought they were designed to be pulled against(tension), not pushed against(compressed). Im not saying you're wrong, Im just having a hard time understanding how that would help?

You are correct that they pull no push. But they need some slop. If you set them tight at the bottom of the stroke they will get too wide at the top of the stroke. If you are able to watch the end of the links as the 3 point rises you will see them kind of arc out as it gets higher. I had the same thing with mine when I switched to the Pats hitch. The normal 3 point ends are smaller and have the rotating balls. The pats doesn't allow for much twist so it forces wider at the top.

 

[LouNY]

Or replace the pins with bolts, a couple of 7/8's bolts and nyloc nuts.

 

[DarkBlack]

You are correct that they pull no push.

The top link is under compression (push) forces, when the scarifiers are digging in.
The bottom links are being pulled on.

 

[chim]

Another vote for turning while under a load as the cause.

 

[jmc]

Another vote for turning while under a load as the cause.

I managed to twist a scarfier shank doing that.

 

[thclimer]

Another vote for turning while under a load as the cause.

Chris, can you confirm that you are lifting your box blade off the ground while making a turn?

It sure seems to me that if the box blade and its scarifiers are engaged into the ground and you make a turn some extreme lateral force is going to be placed on the plate in the picture which is bent.

 

[IndyIan]

Chris, can you confirm that you are lifting your box blade off the ground while making a turn?

It sure seems to me that if the box blade and its scarifiers are engaged into the ground and you make a turn some extreme lateral force is going to be placed on the plate in the picture which is bent.

I guess it is a light duty box, but you would hope they would make the hitch points better than that... It looks like the designer was counting on sway adjusters that are inboard of the lower arms, but now almost all small tractors now have outboard sway control adjusters. A bolt and nut seems to be the easiest solution though, to get the both tabs on the box working together not to bend.

 

[chris the wrench]

Chris, can you confirm that you are lifting your box blade off the ground while making a turn?

Yes, well that depends on what you consider a turn. I would say I change direction by less than 10 degrees.