Backhoe Bobcat Backhoe on a Grand L series

[design]

I wish I could change the thread title to a Woods 9000 BH on a L series. At this point this appears to be the better deal. As for the frame, I spoke with our local Kubota/Woods dealer and there is no sub-frame that will fit.
My options are:
1. Modify the L3130/Woods9000 4 point frame to fit the 2900
2. Build my own
3. Use the L2900/Woods 7500 subframe and modify to fit the backhoe.

At this point I am leaning toward option 1. The dealers head of service made the following helpful suggestion:

"Make sure the load from the hoe goes to the loader frame and not to the tractor." ie. If you pick the tractor up with the bucket and the out riggers, (all four wheels off of the ground) and the backhoe subframe connects only to the loader mounts, you can not brake the tractor.

This seemed like good advice.

Any thoughts.
Design

 

[Jay4200]

A woods 9000 3pt BH became available for a good price <$3K. Would I be better off using the smaller BH9000 instead of the larger Bobcat?
Who has plans for the woods subframe? I have some welding and fab experience and a new Ranger 8 waiting for a project to be tested on.
I welcome any input....

I have a Woods BH9000 on my L4200 with a subframe mount. The L2900 is the same basic design, just a little smaller everywhere. <$3k is a great price for a BH9000, incidentally - typically decent used ones are ~$5k.

A backhoe generates some really violent forces - not so much when its doing normal stuff, but when you make a mistake, things get ugly fast. My BH can (and does) toss my L4200 around like it's made of tissue paper. I think that a 9' backhoe will rip your 3pt hitch off like its made of sticks. The Bobcat 'hoe will work too - it's of similar weight to the Woods. I wouldn't worry too much about hydraulic volume, but the backhoe might move a little slow. Personally, I wish my BH9000 was bigger (I have excavator envy).

The real problem is weight - the backhoes sit pretty far behind the tractor. You could find yourself riding wheelies everytime you hit the gas. You could load down the front, but then you have to worry about axle loading.

The L2900 is only rated for a 7.5' backhoe, but I think it could carry a BH9000 no problem -BUT- you definately need a subframe mount. They are little more than a couple of pieces of square stock, so if you can't find one, make one. If you can get a subframe mount for another backhoe, you could probably modify it for whichever 'hoe you end up with fairly easily. Even if you have to use a 7.5' mount for a 9' backhoe, it'll work.

JayC

 

[dfkrug]

My options are:
1. Modify the L3130/Woods9000 4 point frame to fit the 2900
2. Build my own
3. Use the L2900/Woods 7500 subframe and modify to fit the backhoe.

At this point I am leaning toward option 1. The dealers head of service made the following helpful suggestion:

"Make sure the load from the hoe goes to the loader frame and not to the tractor." ie. If you pick the tractor up with the bucket and the out riggers, (all four wheels off of the ground) and the backhoe subframe connects only to the loader mounts, you can not brake the tractor.

Sorry you can not a get a ready-made subframe for that hoe.

My first choice would be to build my own. You can mount the hoe
closer in to the tractor than pre-built subframes allow. This reduces
the bad effects of having such a heavy weight hanging out so far. Go
look at how close the hoes are mounted on an L35/L39, or even a
BX24 with the BT600 hoe.

2nd choice is modify a subframe built for the L2900. The harder part
is done, which is your tractor-specific mounts on your rear axle
casting. When you pay your $1000 for the Woods L3130 4-pt subframe,
you might have wished you went to build-your-own.

Backhoe subframes are supported by the loader subframe AND stout
connections to the rear axle housing, usually bolted to factory-provided
threaded holes.

 

[design]

Thank you for all the encouragement. If all goes well I hope to pick up the Woods 9000 this weekend.
The frame may take till spring, but that seems like a good winter project anyway.

Jay4200: As you are just down the road and I work in Hollis, live near Concord I would love to see how the 9000 is attached. I am sending you a PM to that effect.

dfkrug: I agree: A custom sub-frame is the way to go. I just need to think about the design. The bottom of the rear axle where the ROPS mounts plus the loader frame should be sound mounting points. My concern is the following three situations:
1. driving with the hoe on the back over rough terrain.
2. working to the side of the tractor and putting large torsion moments through the frame/sub-frame.
3. Is the 480 loader capable of taking the loads from having a large backhoe pick the tractor up? It is possible that the tractor could end up supported by only the backhoe arm and the bucket

It seems the 3130 has a little more width at the rear axle then the 2900. Can I squeeze a .25 wall 2”x4” box beam between the rear wheel and the frame/ROPS? Should I try to go inside the ROPS? What about spacing the rear wheels off 1 inch each side( Custom adapters) I know this will increase the bending moment through the rear axle. Can the tractor take that?


Design.

 

[dfkrug]

I agree: A custom sub-frame is the way to go. I just need to think about the design. The bottom of the rear axle where the ROPS mounts plus the loader frame should be sound mounting points. My concern is the following three situations:
1. driving with the hoe on the back over rough terrain.
2. working to the side of the tractor and putting large torsion moments through the frame/sub-frame.
3. Is the 480 loader capable of taking the loads from having a large backhoe pick the tractor up? It is possible that the tractor could end up supported by only the backhoe arm and the bucket

It seems the 3130 has a little more width at the rear axle then the 2900. Can I squeeze a .25 wall 2”x4” box beam between the rear wheel and the frame/ROPS? Should I try to go inside the ROPS? What about spacing the rear wheels off 1 inch each side( Custom adapters) I know this will increase the bending moment through the rear axle. Can the tractor take that?

I have tried a number of different strategies with the subframes I have
made. Some used a ladder-style subframe that always stayed attached
to the hoe when it came off. My latest uses a system like the Woods
4-pt subframes that leave a substantial part of the subframe on the
tractor all the time. I would not do this if the tractor used a mid-mnt mower
at any time. This kind of subframe connects at 4 pts above and below the
rear axle.

Every tractor is different and I think you should view examples to see how
hefty you need to build things. I looked at, measured, and photo-ed many
before I attempted my first custom job. There are many ways to do a
custom subframe that will be strong enough. It is OK to use rect tubing,
channel, or plate.

It is OK to use the same connection that the ROPS uses on the rear
axle casting. This photo I am posting is of the Woods 9000 on an L4830.
You can see that there are not a lot of extra holes provided on the
axle casting. Kubota has been kind enough to provide an "ear" on the
ROPS bracket with holes for the subframe to mount. You can also
remove your ROPS bracket and weld an ear on it. I did that for an
L2500 and it worked great.

All the tractors I have mounted subframe hoes on are capable of
lifting themselves off the ground with hoe and loader. Not a "good"
regular practice, but doing that should not damage the tractor.

My current Kioti CK30 project is totally different....I plan to post pix
soon.

 

[dfkrug]

...here is the Woods 9000/L4830 subframe shot....

 

[john_bud]

Thank you for all the encouragement. If all goes well I hope to pick up the Woods 9000 this weekend.
The frame may take till spring, but that seems like a good winter project anyway.

dfkrug: I agree: A custom sub-frame is the way to go. I just need to think about the design. The bottom of the rear axle where the ROPS mounts plus the loader frame should be sound mounting points. My concern is the following three situations:
1. driving with the hoe on the back over rough terrain.
2. working to the side of the tractor and putting large torsion moments through the frame/sub-frame.
3. Is the 480 loader capable of taking the loads from having a large backhoe pick the tractor up? It is possible that the tractor could end up supported by only the backhoe arm and the bucket

It seems the 3130 has a little more width at the rear axle then the 2900. Can I squeeze a .25 wall 2”x4” box beam between the rear wheel and the frame/ROPS? Should I try to go inside the ROPS? What about spacing the rear wheels off 1 inch each side( Custom adapters) I know this will increase the bending moment through the rear axle. Can the tractor take that?


Design.

You have to design the mounting stout enough to hold the tractor rigid. If you don't - bad things can happen. (See the attached pictures) Those castings are 3/4" thick on the differential and 1/2" for the transmission. Both were replaced as that was more economical than repair. The factory sub-frame is 3/8" x 2" x 6" C channel. But the hoe is a 14' dig and about 3000# weight. The tractor is an industrial Ford (basically an 841).






Don't mean to scare you off of this project, if you can get 1/2x2x4 tube, it should be fine.

jb

 

[Jw5875]

Here are pics of my "Kubota certified re-enforced bracket part" to beef up the top link bracket on the rear end housing recommended for heavy box blade and backhoe attachment. Also they have a heavy duty top link pin that goes in to this bracket. Previously ??? yr or so, a post was made with pics showing a rear end housing that had broken because this bracket was not installed along with a 3 pt hoe attachment and no subframe

More inquirement found that this part is needed for heavy/stress making rear attacments. along with the subframe.

Pics are on my L3400.

Of course it is a piece of $3.00 steel from the scrap yard that you could make, but to keep my warrantee, I paid $xx.xx for this "Kubota" part.

I welded the original two piece bracket to this, the design seemed to me that the bolts coming through the new bracket, only made a "washer" part with the original brackets bolted to it. (Bolts could still be pulled through along with housing piece)


Hope that future backhoe attachers research more for all the parts that are needed, and the salesman can also advise.



"Just Trying to save my rearend" (punn intended)

jw5875

 

[dfkrug]

The better subframes (like the Woods 4-pt and Kubota BT
series) make no use of the toplink bracket at all.

Also, don't forget, this is a 1300# hoe, not a 3000# hoe.

 

[design]

The more I think about the design, the more I want to copy the B21 (B26)/L39 sub-frame. Having the hoe close to the tractor offers several advangtages:
1. There is a greater departure angle
2. The hoe can be closer to the ground (with out effecting departure angle as much) meaning the outriggers will be able to lift the tractor higher off the ground. Helpful for working on a side slope or uneven/soft ground.
3. The load is better shared between the two axles (not by much..) when the hoe is not in use and is ridding about as a counter weight.

Again, thank you for all of the suggestions. God willing, I am picking the 9000 up tomorrow.

Design.