Broken Backhoe Subframe Repair

[brown40]

Really sorry to see that. Looking at the pictures you can see what a tiny sliver of casting they tapped into between the vertical and horizontal ties.
I think the engineer accounted for zero vertical shearing from the backhoe. I don't think that's enough metal to do the job properly, but expect the back of the tractor was supposed to be off the ground/supported by the stabilizers? Was it configured right, or was the full weight of the backhoe subframe hanging off the casting between the wheels while the work was getting done?
Many of them are designed to put the lion's share of forces on top of their stabilizers. It could be put back together, or replaced with factory parts, but neither makes the casting any thicker where it ought to be. Another 1/4 inch of thickness in the cast and distance between the taps would have made a difference--even if they'd just shifted the horizontals up another 1/4 inch it would have left some metal. Hope the fix goes well--I'd attempt one patch, then bite the bullet--won't hurt anything but a failed casting that still is intact for holding fluids and moving parts where they need to be.

 

[dfkrug]

Kioti DK50 w/ KB2485

Oh, dear! Pls post more pix of the subframe and how it is attached to the hoe.

Did you use the hole under the hoe seat for a rigid toplink connection?

 

[DK35vince]

So the subframe ripped off the tractor housing - see pictures below. I have a welder who says he can weld it so 'it will never come apart again.' Should I trust him to weld it or should I spend the extra coin to replace the parts with new?

View attachment 440776View attachment 440777View attachment 440778View attachment 440779

Can't tell from the pictures, were the bolts that go through the sub frame mount into bottom of the rear end housing there and pulled out also or were they loose or missing and that's what caused the problem.

 

[whis]

Go to youtube and search Amazing Blaze at heatin ana beatin welding. If he can't fix it it can't be fixed

 

[hutchman]

Can't tell from the pictures, were the bolts that go through the sub frame mount into bottom of the rear end housing there and pulled out also or were they loose or missing and that's what caused the problem.

Looks to me like it was 4 horizontal bolts and two vertical up from the bottom. My casting (different brand) has two threaded bolt holes in the bottom too. Looks like all 6 casted holes let go.

 

[DK35vince]

Looks to me like it was 4 horizontal bolts and two vertical up from the bottom.

My DK 35 has a similar setup to this one and there at least 4 vertical bolts up from the bottom

 

[hutchman]

After seeing this and also what I've experienced working on fabricating my own subframe mount ... I'm going to use some kind of thread sealer to keep moisture/rust out. I removed one of my rear bolts where the transaxle/ROPS meet and I was shocked at the rust that was on the threads. The rest weren't bad but one was pretty bad. I got new bolts and chased the hole with a tap to clean it up and will be sealing that sucker with some kind of thread sealant to nip that stuff.

 

[DK35vince]

I looked at my DK 35 rear sub frame mount (similar to the OP"s)
The 4 vertical larger diameter bolts that come up from the bottom are the main support bolts, the smaller diameter bolts you see in the rear of the machine in the OP photo's were originally used only for the PTO shield.
The sub frame mount extends up there for some extra support, but if the main vertical bolts were loose or missing the rear horizontal bolts don't stand a chance.
I'm still curious if any of the OP's main vertical bolts were loose or missing that caused the issue.

 

[DK35vince]

Forgot to mention, I have been running the same size backhoe as the OP ( 8 1/2' digging depth) on my DK 35 since 2003 with no issues so far.

 

[OutBurst]

Hopefully I get an update from the welder this week - will keep you all updated.