how to build your own custom backhoe subframe

[PHPaul]

Wow. What a thread!

I had a JD750 with a Woods 650 3PH backhoe with it's own reservoir and pump. Given the rather wimpy hydraulics on the 750 the pump was the way to go.

I have recently replaced the 750 with a new Kubota B2650 with a cab.

A bit of experimentation indicates that the old Woods hoe isn't going to work due to clearance issues with the cab. Add to that concerns about stresses from mounting it to the three point and I'm in quite a bind.

My first thought was some sort of adapter or subframe, but looking at this post makes me wonder if it's worth the trouble, especially considering that I'll need to mount the hoe well aft of the tractor for the seat to clear the cab and provide a decently comfortable operating position.

The hoe is 20 years old and I've done pretty much all the ditching/landscaping work it was bought for. I only use it perhaps 2 or 3 times a year now. Given that, the technical difficulties of fabricating a mount that won't involve a day-long process of mounting and dismounting the hoe, and the problems inherent in mounting the hoe so far from the rear wheels, I'm seriously considering selling it and just renting a trackhoe for the odd occasion that I need some serious digging power.

With that in mind, has anyone ever adapted a 3PH hoe to a tractor with a cab?

 

[dfkrug]

I'm seriously considering selling it and just renting a trackhoe for the odd occasion
that I need some serious digging power.

Nothing digs like an excavator. If doing a large digging project, then it is nice to have a tractor around
AND a mini-X.

 

[Reg]

Going hand in hand with all this is ease of installation and use. While having a firm attachment system is great, if it is difficult or impossible for one person (sitting in the driver's seat) to back up to and hook up...well, it's not worth bothering with.
This is the balancing act the designers must struggle with. I know the BH ladder type subframe for my Kioti DK45 isn't all that great (kioti BH). I wouldn't want to use it all day every day, but it sure is easy to hook up.
One that requires crawling under the tractor, installing bolts and other calisthenics should be considered as poor design, in my book.

Old thread, but I came back to it to find a pointer to it for someone else.

I agree, at least in principle.
Mine is "acceptable" to hook up, I don't have to squirm around under the tractor with it half hooked up - THAT would be unacceptable on safety grounds.
Once in position I do have to get down low BESIDE the tractor to put a latch holding pin in on each side, little to no risk there.

The Amerequip hoe goes a long way toward "helping" the hook-up by use of the hydraulics for final positioning and pivoting, but you still need to come back at it fairly well aligned and square.
Where I would like a little more help is with final side to side positioning, perhaps some sort of guide-in/slide-in tapered slots for the rear hooks to get the tractor and hoe aligned that final ....awww, I dunno, maybe it is 3/8 inch on a good day.
It is more than I want to bully with pry bars or side to side rocking of the hoe with the stabilizers.
If they allowed me an inch left or right of center life would be SO much simpler.

Probably a standard trick, but I stand beside the tractor on the right side and use the bucket curl to back in the final few inches.
It seems to be the only position where I can use all the hoe controls and loader joy stick for wiggling and jiggling everything together.
I don't want to be ON the tractor or in the hoe seat until all the latches are up and pins are in, beside it at least FEELS safer.

 

[dfkrug]

Since I made my last few subframes, I have learned something that would effect the next one
I make.

Recall that there is a trade-off that I discuss at length about using pins vs. bolts/nuts to connect
a 4-point subframe to the tractor. Pins are easier to install/remove, but they are not tight, so
clearances will only increase with use.

When I made the subframe for my Kioti, I used 1" fine-thread bolts and nylock nuts. The holes
were precision-drilled with very tight alignment.

Recently, I did a 400-hr service on my tractor, which required removal of the subframe to access
one of my hyd filters under the tractor. Removing these bolts was harder than I expected
because the slight unavoidable flex of the subframe caused "threads" to be worn into the 1/2"
plate. That meant that these large bolts would not slide out easily after the nuts were removed.

In the future, I would only use bolts that were threaded only where the nuts required them. The
rest of the bolts would be smooth. This means buying extra-long bolts, and cutting/welding
new heads on them to achieve exactly the correct length.

 

[Fawken]

In the future, I would only use bolts that were threaded only where the nuts required them. The
rest of the bolts would be smooth. This means buying extra-long bolts, and cutting/welding
new heads on them to achieve exactly the correct length.

Seems to me you could get #5 grade bolts that are close enough that a few #5 flat washers and lock nuts would achieve the desired effect. Or even a spacer. For my own sub frame I trimmed some #8 and stainless bolts- on the thread ends only.

 

[Sprinklerman]

Very good reading . I am picking up a john deere 8B backhoe . But I have a new holland tractor . I think I read somewhere that it may be the same backhoe as the new holland 757c or 758, both made by ameriquip . If so this may make my installation much easier . Does anyone know for sure if this is true?

 

[Toofarnorth]

So this has been some great reading. I have been floating around on here reading and I decided to join to share my next job and get your input.

I recently acquired a JD94 backhoe from a 70's JD400 industrial tractor. It is a pretty good sized hoe (15') and is probably bigger than what is recommended for my Mahindra 5500, although my Mahindra 00 series is well sized and has an extra long frame that will help.

I have been completely re-hauling the JD94 hoe with new valve bank and all new hoses, honing and re-sealing the cylinders, as well as converting over to self contained OC system running off a prince 21gpm pto pump and 21gal tank. Also as with any old commercial equipment pivot pin holes are pretty well worn and I am almost done building my own line boring tool to oversize, re-bush, and re-pin everything.

After that will be the job of designing and fabricating the sub-frame that can effectively carry and distribute the weight.

It has been a fun project so far I just want to be careful about building a rugged enough sub-frame.

 

[ch47dpilot]

I found a bush hog backhoe for sale at an online auction. Bush hog shows the subframe for my tractor, Kubota L3400, as a belly style. Other tractors they show as 4 point. I assume the 4 point is similar to designs talked about here. My question is what is a belly style and anyone have pics of one.

 

[dfkrug]

Bush hog shows the subframe for my tractor, Kubota L3400, as a belly style. Other tractors
they show as 4 point.

I assume you have already tried to find a picture of that BushHog subframe. If you do find one, post it. They may
be referring to what I have called "ladder-style".

 

[ThisJustin]

It's been over a year since anyone has posted on this thread but hopefully some people are still around. I'm considering matching up a Bradco 609 or 611 with my Kioti DK45S, I'm hoping someone has some pictures and ideas for a subframe. The DK45S was only made a few years starting around 2005, I'd really like to see some photos of the tractor with a subframe whether it's DIY or from one of the manufacturers.

I called Bradco to see if I could get a subframe from them and they do make (or did make) a subframe for my machine but it's made for the KL1590 Loader and I have the KL451 Loader. Additionally, the Bradco Rep. said that procuring the subframe would be expensive, around $4K-$5K. He sent me the part numbers I would need and drawings of the subframe for the KL1590:
108550 TR Half Kit
108565 BH Half Kit

Excellent thread btw, thanks for all the info DFkrug.