Broken Mount For LA724

[kcender]

The close up of the break is too blurred to tell if it's ductile iron or cast steel. I'm leaning towards cast steel as the reflection off the break is quite shiny.

I am assuming it is cast steel by the orange sparks that come off of it when I touched it with a grinder.Cast iron generally gives a red spark.Also the existing factory welds and the amount of them would lead me to believe it is cast steel.I think cast iron would not be used in this situation because of the difficulty welding it,especially the amount of weld where it is welded to the steel pipe.It could be cast iron but I would be very surprised.

 

[PapaPerk]

I am assuming it is cast steel by the orange sparks that come off of it when I touched it with a grinder.Cast iron generally gives a red spark.Also the existing factory welds and the amount of them would lead me to believe it is cast steel.I think cast iron would not be used in this situation because of the difficulty welding it,especially the amount of weld where it is welded to the steel pipe.It could be cast iron but I would be very surprised.

There's 3 materials in question. Cast iron, ductile iron, and cast steel.

The bracket is certainly not cast iron. Cast iron is the weakest of the three and used for things like exhaust manifolds and cooking pots.

Ductile iron is used extensively in equipment application and other high load conditions where a casting is needed.

Cast steel has low carbon content and is stronger than ductile iron I believe. Not sure how common it is in the tractor industry.... maybe quite common but I don't know.

So it's either cast steel or ductile iron! LOL But seriously... why not just make the bracket out of 1045 cold roll plate that's bent and welded... instead of going through the trouble of making a casting?

What would be very awesome is a forged loader bracket! That would be a tough customer.

What has Kubota said about this failure?

 

[beppington]

What would be very awesome is a forged loader bracket! That would be a tough customer.

Doesn't that just mean it would probably break somewhere else? This may be one of the cheaper "sacrificial" pieces in the loader's structure.

 

[PapaPerk]

Doesn't that just mean it would probably break somewhere else? This may be one of the cheaper "sacrificial" pieces in the loader's structure.

I'm not big on "sacrificial" machine parts. And I doubt Kubota considers that loader bracket to be sacrificial.

Using the excuse that a vehicle's poorly designed part is there "to prevent damage to more expensive parts" is BS. That's the line the service writers use at the auto "stealerships" all the time! LOL!!!!

 

[ritschner]

Interesting, I was at the dealer the other day and noticed that they had changed the loader brackets. It appeared as though they would not be as strong as the older units.

 

[PapaPerk]

Interesting, I was at the dealer the other day and noticed that they had changed the loader brackets. It appeared as though they would not be as strong as the older units.

Yeah I was looking at my 3830 too. It's brackets are very beefy! U shaped bent steel plate. They look bomb proof. Kubota may have "flub their dubs" on the new brackets. Will be interesting to see how this develops.

 

[crazyal]

kcender. I would have someone inspect both brackets, mag particle would be my choice. It's possible you could have cracked the other bracket or have a second crack.

 

[rswyan]

kcender. I would have someone inspect both brackets, mag particle would be my choice. It's possible you could have cracked the other bracket or have a second crack.

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

 

[Chilly807]

After taking a closer look at the design of the pillars, I've gotta say I think it's a design problem. It reminds me of the Deere loader setup on some of their smaller tractors, like the 2305 for example.

Mine (about the same HP and a LOT less loader capacity), is a bent steel U-channel that the loader fits into. I really don't know the reasoning behind building a loader bracket this way, but I think it's on the light duty side of the fence for a tractor with that much HP.

Any side load at all is going to put some stress on that cast steel structure that it's not formed to take.

Sean

 

[Baby Grand]

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?:







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