Broken Mount For LA724

[kcender]

Strange ... looking at the OP's original photos ... and then at my FEL, which was bought in July 2007, there appears to be a difference. My cast uprights have a heavy (sheet steel?) "flitch" plate, 3/16 or 1/4 inch thick; filet welded to the web of the casting. This reinforcement runs almost the full width of the upright and extends almost a foot vertically. I don't see any evidence of it on the OP's, or maybe I just can't see it?:

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I may have to eat crow about Kubota wringing out weight without going overboard ...

Kcender, does your FEL have these plates, and is it newer than mine, or older?

-Jim

My tractor was purchased in July of 2010 and does NOT have these plates.This is new knowledge to me and very interesting.It seems like maybe Kubota cut some corners here to save some money on manufacturing costs.Who is to say if this would have prevented my problem but I would certainly think it would have made the bracket stand up better.I will mention this to the dealer when he looks at it.If Kubota doesn't do anything for me,and I won't be surprised,this is what I had planned on doing when I weld
the brackets.The only difference is that I was thinking of putting the plates on the inside but I don't see much difference one way or the other.Thanks for the photos and this helps to reinforce that the casting is weldable and probably cast steel judging from the amount of welding done to it.Cast iron usually doesn't accept this amount of weld without a lot of care that I don't think Kubota would be willing to do that.

 

[The Haymaker]

Bummer


Just curious - what does your owners manual have to say about performing these type of manuvers ?


On a heavy-duty industrial backhoe maybe .....


Correct.


It's not so much that they are only made to do light work as much as it a case that they are not made to be completely abused ....

Just like any machine, they have their place, and they have their limits .... exceed the limits and you will likely have a problem at some point.


Personally, if I were you, I'd consider myself lucky - the loader mounts can probably be repaired fairly easily.

Imagine if you broken the ___________ (fill in the blank: rear end/differential, transmission, etc. ....)

I wouldn't call that abuse. For the amount of money we spend on these units, we shouldn't have to treat them like on of my boy's Ertl toys. Abuse to me would be trying to move a brick house with the bucket, not having it support the tractor with no impact.

E

 

[kcender]

Baby Grand,just want to make sure if you bought the tractor new and that the extra plates were part of the manufacturing process from Kubota or is it possible that it was done later.

 

[arsenix2001]

I wouldn't call that abuse. For the amount of money we spend on these units, we shouldn't have to treat them like on of my boy's Ertl toys. Abuse to me would be trying to move a brick house with the bucket, not having it support the tractor with no impact.

E

I hear what your saying, but nothing is indestructible, and these are not full framed permenant loader tractors. They are added to an ag tractor for moving material and light/medium digging. The hoe puts extreme stress over what is normal to boot. Its hard to guess without watching every hour of the ops use. Im not backing kubota by any means, believe me... I have the exact same 2010 loader mounts he does and its bothering the heck out me now that I see they deleted that gusset plate which was there for a reason. Ive watched my mounts flex also. Has me bit concerned and im curious what kubota says.

 

[crazyal]

Apparently you missed it where the OP said:

"After looking at the other bracket I noticed that it has a crack in it as well ....."

See pic no. 5 in the OP

It's not the crack you can see but the ones you can't that will cause the plates to fail, hence the NDT.

 

[Chilly807]

My tractor was purchased in July of 2010 and does NOT have these plates.This is new knowledge to me and very interesting.It seems like maybe Kubota cut some corners here to save some money on manufacturing costs.Who is to say if this would have prevented my problem but I would certainly think it would have made the bracket stand up better.I will mention this to the dealer when he looks at it.If Kubota doesn't do anything for me,and I won't be surprised,this is what I had planned on doing when I weld
the brackets.The only difference is that I was thinking of putting the plates on the inside but I don't see much difference one way or the other.Thanks for the photos and this helps to reinforce that the casting is weldable and probably cast steel judging from the amount of welding done to it.Cast iron usually doesn't accept this amount of weld without a lot of care that I don't think Kubota would be willing to do that.

It looks like a different casting altogether, I don't remember your's having as many "pockets" on the back side, and it definitely doesn't have the reinforcing plates welded to the outside.

Ritschner mentioned earlier that he thought they had changed the brackets recently. Maybe they tried a new design that wasn't supposed to need the plates welded to it, with a lack of success in this case anyway.

It might be stronger with the plates on the inside. From what I saw of yours today, it looks like they both cracked on the thinnest part of the web on the inside of the casting first, then spread to the outside. If you stiffen the inside, the web might not crack as easily, I think the steel will flex more if it's on the outside.

It'll be interesting to see what the guys from Nova have to say about it. May be worth talking with the regional rep from Kubota directly if the dealer can't do anything for you. Where they both cracked in exactly the same spot makes me think there's a problem with the design to begin with.

Sean

 

[kcender]

Sean,your eyes are sharper than mine.I just had a look at my brackets and they do appear to have a different web pattern than the ones on Baby Grand's.Mine must be the new and improved version:laughing:I will definitely mention this to Terry when he comes to look at the tractor.I think you are also right about putting the plate on the inside which is what I was thinking.I was thinking of both sides but I have to consider the inherent stresses from welding,more is not always better unless I had a way to stress relieve the part after welding. This would require a sizable furnace which I do not have.

 

[The Haymaker]

I hear what your saying, but nothing is indestructible, and these are not full framed permenant loader tractors. They are added to an ag tractor for moving material and light/medium digging. The hoe puts extreme stress over what is normal to boot. Its hard to guess without watching every hour of the ops use. Im not backing kubota by any means, believe me... I have the exact same 2010 loader mounts he does and its bothering the heck out me now that I see they deleted that gusset plate which was there for a reason. Ive watched my mounts flex also. Has me bit concerned and im curious what kubota says.

Don't get me wrong, but there's many things I see mentioned here that some call "abuse" and I say "I won't be buying their product." What do they think we are going to use these things for? Expensive lawn ornaments? The whole "not made for pushing" line I see time and time again drives me nuts. Yeah, expect damage if you're pushing in mid range and strike a tectonic plate, but to spend the money for a 4000lb tractor with bucket and be told it is for nothing other than shoving around styrofoam is BS in my book.

I use my tractor for everything under the sun. I can't afford to go out and buy another complete piece of equipment, like a dozer, a skidder, and excavator, and so on for every job I expect my piece of equipment to do. My Boomer has done all of the above. No, it's not wanton crazy abuse of the tractor, I do everything I can to prevent heavy jots and bumps, whether it be mowing, box dragging, or transiting loam from the 60 year old pile down in the woods up to my lawn in progress.

Abuse, and expecting a failure, would be backing into a guardrail post at a low (not slow) speed with a rear mount finish mower. Yes, there was a failure, but no where near what I expected for the amount of force dissipated. ( the shop press and a set of falls got a workout on this one).

Breaking a FEL stanchion or even worse, breaking a tractor in half and being told "you shouldn't have put weight to it" is simply inexcusable and should put a mfg'er in a shameful position with it's sales base.

That said, yes, be thankful the failure was what it was. A few hours with plasma cutter and welder would make for a quick (and, obviously, better than new) fix if the manufacturer doesn't stand behind its deficient product. And, if you are already seeing the mounts flex, I'd be fabbing some backing plates and whatever gusseting is needed. That metal will only bend so many times before there is a fatigue related failure.

I think I need to grab my Dos Equis and head back downstairs to the Garagemajal.

 

[rswyan]

I wouldn't call that abuse.

Doesn't matter .... since it is not relevant.

For the amount of money we spend on these units, we shouldn't have to treat them like on of my boy's Ertl toys.

That's certainly true ......... however ..... one should treat them like what they are (CUT's with an add-on backhoe) ..... not like what they are not (industrial TLB's)

Abuse to me would be trying to move a brick house with the bucket, not having it support the tractor with no impact.

It really matters very little what you - or I, for that matter - consider abuse to be.

What is relevant is what who designed, manufactured, and sold/marketed the machine considers abuse to be ....

If I had to hazard a guess, I'd say that the machines are designed with very specific intended use .... in my book, using them in a manner other than what they were designed for constitutes abuse ....

Do I do that ? ...... of course ....

But I ain't gonna blame the manufacturer if there's a problem when I do .....

Just because you (or I .... or anyone else for that matter) "feels" things "ought to be a certain way" does not mean that they are.

I don't own the OP's particular model of CUT, loader, or backhoe - however, I do know what Kubota says in the manual for my backhoe (BH4690B - which fits both "B" and "L" series Kubotas):

"Due to the configuration of the tractor, with separate operator's stations divided by the ROPS, the backhoe should not be used to move the unit. The boom and dipper and both stabilizers should be raised to clear ground level, and the unit should be moved along the trench line or excavation with the tractor."

Seems fairly straightforward to me ....

Additionally, it says the following, with regard to using the backhoe to backfill an excavation:

"DO NOT use the side of the bucket and lateral swing to attempt to backfill. This method places huge stresses on the entire backhoe frame that will cause major failures that can effect the entire tractor-loader-backhoe." [Emphasis mine]

And finally:

IMPORTANT:
Lateral swing backfilling is perhaps the most common abuse placed on backhoes today. All backhoes are designed as digging units. They are not to be used as prying units.

Personally, I think it really isn't all that difficult for a fairly intelligent person to draw some reasonable conclusions from the above cautions.

 

[kcender]

Terry from the dealership where I bought my tractor was just down to see the bracket.He said he found it hard to believe that the bracket broke.I showed him the crack in the other bracket and he agreed the cracks were in exactly the same place on both brackets.He took pictures and said he would contact Kubota the first of the week.I told him I didn't expect much from them but he said you never know how they are going to respond.I mentioned to him about the brackets on Baby Grand's tractor with the reinforcing plates and he asked me to send the photos to him,which I did.So now I wait.