Broken Mount For LA724

[kcender]

Well Case would disagree with you. There are parts on my 580K that are cast and even have the words "do not weld" cast into them. Things like the front axle and the backhoe boom are ductile iron.

I figure because Kubota welds these cast brackets to the steel pipe,it should be a weldable casting.As I have previously stated there is a difference between ductile iron and cast steel,which I feel these castings are made of.As for lifting the bucket I would agree that it would be a good practice to adopt.

 

[Baby Grand]

I just got home from work to find Terry from my local Kubota dealership along with the regional rep for Kubota.The rep was anxious to see the brackets and said it has generated quite a stir up through the ranks at Kubota.Apparently they had never encountered this before and were quite surprised that it happened.He agreed to replace both brackets without question,saying it should never have happened and apoligized to me for it hapenning at all.Apparently he can find no record of any changes ever made to the manufacturing of the brackets but acknowledged the difference in the pictures of Baby Grand's tractor.He offered to try and get me these brackets but I told him I would prefer the original type of bracket so I can weld on the reinforcing plates.We discussed the welding of these plates and he thought it was a good idea.He has no trouble with me doing the welding as I am a certified welder but was willing to pay a welding shop to do the work if I had wished it.He also said for the dealer to have the brackets powder coated after the welding is done as that is how they are originally painted.They are going to try to find me a set of brackets in the system but if none are available,they will take a set off a tractor on the lot.As for the timeline,I broke the bracket Wednesday evening,my dealer came down to see the tractor Sunday evening on his own time[Friday was a holiday],and the rep came on Tuesday.The retail price of the brackets is over $1100 per side.I am more than happy with the response from Kubota and feel I couldn't have been treated any better.

Excellent news - I'm very glad to hear that! Not only for you, but for all of us who own Kubota products, knowing that the company is taking responsibility foir this one. Sounds like your dealer is first rate, too.

 

[Baby Grand]

Well Case would disagree with you. There are parts on my 580K that are cast and even have the words "do not weld" cast into them. Things like the front axle and the backhoe boom are ductile iron.

The parts you are describing sound like they would be candidates for castings - basically anything that would require a lot of material removal to produce from bar or plate stock. I'll admit, the backhoe boom surprises me, but I could see it, depending on the shape. There must have been an interesting exchange between the design engineer and the senior engineer.

 

[MHarryE]

Glad you got such good response from both your dealer and Kubota. It appears obvious they want to keep you as a customer. I am on my third dealer, this one 150 miles from me. Now that I am retired I had time to listen to neighbors, hear the good and the bad experiences everyone had, and dealer rose to the top.

The computer analysis today can do wonderful things but it requires the right input. As an example, several years ago I was tasked to validate a new planetary drive engineering had sourced from one of our reliable suppliers. A few weeks into the test program my best driver called to tell me the machine stopped, drive locked up. People from the supplier came to our plant where we tore into it. It was trashed but we could tell from the failed parts it was overloaded. Next came the conference where I asked Engineering where they got the load data they gave the supplier. Turns out they sent a summer intern out to our proving grounds with a pressure recorder and had him run for a couple hours, then analyze the data. New kid, intern, looking for a job after graduation - last thing he wanted to do was break a machine. Our R&D guys instrumented the test machine and a senior engineer and I each ran through what we considered we had seen our roughest customers did. I analyzed the results and took them to Italy to talk to our supplier. They analyzed the results in their computer and came back to our conference room saying the Italian equivalent of "Holy S**t". No way could the planetary stand up to those kind of loads. Sometimes these things make it past the test guys - it happens in every company. Then it comes down to how the company responds. Some companies tell you that you abused the product, it's your fault. I think of those companies as the ones now longer in business. The ones who treat their customers right (without customers, you have no business) are the ones who are in for the long term.

 

[Baby Grand]

<Snip>

... Sometimes these things make it past the test guys - it happens in every company. Then it comes down to how the company responds. Some companies tell you that you abused the product, it's your fault. I think of those companies as the ones now longer in business. The ones who treat their customers right (without customers, you have no business) are the ones who are in for the long term.

So true!

 

[crazyal]

I figure because Kubota welds these cast brackets to the steel pipe,it should be a weldable casting.As I have previously stated there is a difference between ductile iron and cast steel,which I feel these castings are made of.As for lifting the bucket I would agree that it would be a good practice to adopt.

I use to work for an NDT company and occasionally would do work in a large valve company inspecting the valves. It's something to watch a robotic welder repair (weld fill) nodule iron 60" valve bodies. Something that could never be done in the field.

I would think the plates would be steel because of the welding on them. I just couldn't see savings in using ductile iron over steel for Kubota once you add in the costs and the hassle of doing the pre and post work to the iron to weld it.

 

[crazyal]

The parts you are describing sound like they would be candidates for castings - basically anything that would require a lot of material removal to produce from bar or plate stock. I'll admit, the backhoe boom surprises me, but I could see it, depending on the shape. There must have been an interesting exchange between the design engineer and the senior engineer.

I think the 580K was the first model to move from a welded box to a nodule iron boom. From their sales brochure.

For better strength to hold up under the toughest conditions, the swing tower,boom, dipper and stabilizer legs are made entirely from a proven, durable, cast ductile iron. (Previous Case backhoes and all competitors use fabricated steel.)


[FONT=&quot]The cast iron adds to backhoe strength because of:[/FONT]
No welds, for constant strength throughout the structures.
It has 62,000 psi (427 474 kPa) of tensile strength compared to 50,000 psi(344 738 kPa) for fabricated steel.

 

[kcender]

Just got my brackets back from powder coating.It was a bit of a wait but the powder had to be ordered in.The colour is Chevy Orange and matches quite well.The dealer dropped off the brackets and gave me a hand getting them up in place and the bolts started.They could have been installed under warranty but I didn't mind doing it.I torqued all the bolts to 166 pounds as stated in the manual.Thought I would add a few pictures.I added a 1/4" plate to both sides of each bracket which should make them considerably stronger than they were.Time will tell.

 

[beppington]

First, holy crap your tractor is clean! :thumbsup:

Second, the brackets look great. Chevy orange matches just fine; I wouldn't have known it wasn't Kubota orange if you hadn't posted that it's not.

Third, do you think you'll do anything different, as far as sliding the loader on the ground with the BH, etc.?

 

[Gizmo2]

First, I will second the "holy crap your tractor is clean"!
Second, I will say that is one of the best looking support bracket addition I have seen in a long time. Maybe it's the paint job but I don't think so it surely looks professional. Thanks for the pictures.

 

[Baby Grand]

Holy crap - your tractor looks brand new! What do you move with that thing, laundry detergent? Nice looking masts, by the way. I like the full radius around the leading and trailing edges. I think I can state without reservation that kcender now has the LA724 loader least likely to fail a mast.
-Jim

 

[Turbys_1700]

Kubota and your dealer did you right...

Sometimes things just happen that are really no fault of the operator or even inherent design of the machine...

You've got a very good dealer and are very fortunate...

 

[Whitnel]

Glad everything worked out for you. Those brackets look like they came from the factory that way, you would never know they have been modified. Very nice.

 

[kcender]

Holy crap - your tractor looks brand new! What do you move with that thing, laundry detergent? Nice looking masts, by the way. I like the full radius around the leading and trailing edges. I think I can state without reservation that kcender now has the LA724 loader least likely to fail a mast.
-Jim

Thanks for the kind words.I only use the tractor to move laundry detergent once a week on laundry day:laughing.The other times I use it to level off my property.I am currently leveling my back yard which is where the bracket broke.I have added a few photos of it.

 

[Gizmo2]

Thanks for the kind words.I only use the tractor to move laundry detergent once a week on laundry day:laughing.The other times I use it to level off my property.I am currently leveling my back yard which is where the bracket broke.I have added a few photos of it.

I have to say there looks to be enough work there for half the members on TBN.

 

[Baby Grand]

I was wondering how you had accumulated all those hours on a 2010 machine - mystery solved. You are doing civil engineering on a scale that I never would have thought to try.

 

[Gizmo2]

I was wondering how you had accumulated all those hours on a 2010 machine - mystery solved. You are doing civil engineering on a scale that I never would have thought to try.

Yeah, kcender is now my new hero.

 

[crazyal]

Thanks for the kind words.I only use the tractor to move laundry detergent once a week on laundry day:laughing.The other times I use it to level off my property.I am currently leveling my back yard which is where the bracket broke.I have added a few photos of it.

Level it? That's a play ground.

 

[kcender]

Level it? That's a play ground.

Exactly,it's all about the journey,not the destination:laughing:

 

[RedNeckGeek]

Just wanted to say thanks for starting this thread. I have the exact same tractor and loader, and the exact same failure of the loader mounts. My situation may be even worse because I've added a much heavier 4-in-1 bucket to the setup. I bought the tractor from a fellow that was using it to clear land in the Santa Cruz mountains south of the San Francisco Bay Area, and from the looks of the bucket and loader arms, this thing really took a beating. Both mounts were broken and weld repaired when I bought it, and both have since cracked again. The first time this happened I ground out the cracks and welded them with MIG and E70S filler, but the cracks came back in the heat affected zone of the weld. Gouged 'em out again and this time preheated to about 400F and let them cool by themselves. That worked for another couple hundred hours until one of the mounts started to crack again. I was in the middle of a job and kept using it until it broke all the way across at exactly the same place as the OP, right through the casting and the side plates that had been added in the original repair. This time I took the mount all the way off the tractor, put a bevel joint on the broken pieces, and again used preheat while welding them back together. I also added a fair amount of filler metal to the webs on the back side of the casting to help reinforce the crack zone. So far I've seen no additional cracking on that side, but now the other side has about an inch of crack that is slowly growing.

I'm going to make a copy of this thread and take some pictures of my mounts and go have a talk with my Kubota dealer. Since the tractor is 8 years old with 1800 hours on it (only a third of them mine) I'm not expecting much. But if Kubota is aware of the problem and they've revised the mounts, it will sure save me a lot of welding and grinding if they're willing to replace them at no cost to me.

The property here is pretty steep and I've moved a lot (if you can call 200 cu. yds. a lot) of fill dirt while running sideways to the slope. I've noticed, especially when I hit a bump with a full bucket, that the upper arms of the mounts flex at least a quarter inch sideways, and that's probably what is causing the cracks to initiate. Those same side loads keep loosening the bolts securing the inner covers on the front 4WD hubs, and what a mess that makes. First time it happened I didn't catch it until the cover broke, sending the wheel and axel out in front of the tractor! My take away from this is that these little tractors are great for landscaping on soft level ground, but here in California's Sierra foot hills where the terrain is steep and full of rocks, they just don't hold up. My neighbor likes to say that Kubotas are fine for maintaining things, but you need a real backhoe to build things.

BTW kcender, when I saw the photos of you moving those dirt mountains, the first thing I thought of was that song about the ant and the rubber tree plant