Backhoe Subframe Help

okgat · Mar 22, 2007

Good day,

I can weld with mig or stick, but I don't know a heck of a lot about design, so I thought someone might be able to provide suggestions. Yes, I have viewed other subframes online, but I need a little more assistance.

I currently own a 2910 New Holland Tractor. I recently purchased an old Arps 728 backhoe. (Please see attached photographs). In reviewing the photos, where would you suggest I attach the subframe that I will build.

1) Tractor photo: There are three possible mounting brackets. Two brackets are shown at the bottom of the rear axle. One bracket is used to mount the swing arm and the other is used to mount the ROP. Then there is the center or middle bracket which would typically connect to a metal bar coming from under the seat of the backhoe attachment.

2) Backhoe photo: The outside brackets are used to mount the swing arms, then there are two other brackets which stick out which I do not know where they would be used. The last main bracket is just under the seat and this normally is connected mid point at the rear of the tractor.

Thanks for your help,

Rick G.

accordionman · Mar 22, 2007

SIR,
sorry, do not see your photos. did it work?
accordionman
wlbrown
wright city,mo.

MikeD74T · Mar 22, 2007

okgat, I adapted a Long 3pt backhoe to a Kioti 45S using a Woods subframe adapter. It just involved installing the subframe adapter on the tractor & welding 2 flanges on the backhoe to fit the Woods adapter. I have less than 8 hours in the entire install. Look here Woods Equipment Company Operator's Manuals
for the manuals for Woods subframes. I didn't see your tractor model, but the manuals will give you a clear picture of optimal attachment points and you may find an adapter that is a direct fit or can be modified to fit. My Kioti dealer consulted the Woods dealer to find one I could modify as Woods didn't have a direct bolt up model for the 45S at the time. The $800 price for the adapter seemed steep but now I have a quality quick detachable mount. I think I posted some pictures a while back under the heading of 'toy box', wife's name for my barn. MikeD74

philbuilt · Mar 22, 2007

MikeD74T,
Thanks for the woods manual idea that gives a really clear idea on how to connect the sub- frame to the tractor.
Again thanks
Phil

okgat · Mar 22, 2007

I too would like to thank you for the Wood's manual idea. Since receiving your information, I have been comparing the 3 pt hook-up on my tractor with that of the backhoe attachment trying to decide a practical layout.

On my 2910, the lift arms are connected to the tractor on each side at the bottom of the rear axle and the center link is then connected to the upper mid bracket. Would someone please explain again, where the stresses occur that cause failures. I ask this because the brackets beneath the rear axle seem "beefy".

Thanks,

Rick G.

jarokoro · Mar 23, 2007

You will want to build a sub-frame that distributes the load stress the length of the tractor frame. Most sub-frames mount to the loader arm mounts (mid tractor) and the tractor axel housing on each side of the housing using existing bolts or changing them out with ones a little longer.

My JD 990 has two frame rails that mount from the loader arm back to the rear axel/rops brackets and then two brackets on each side of the rear axel housing. I have no 3 Point connections at all to my back hoe it is secured by a locking mechanism on the front rails and sits on the rear mounts only. Someone with more engineering skills, more time and more importantly money then me; came up with idea because of structural integrity issues, breakage and ease of installing and removal otherwise my BH would mount on the lift arms.

There is quite a bit of threads about this subject but the bottom line is if the BH is of any size or weight (600 lbs +) you want it to spread the weight and stress to the entire tractor. I looked up your model tractor and at around only 37 HP anything that will dig more than 4’ I would want mounted solid so not to break the tractor in half.

I will post pics if I have time.

MikeD74T · Mar 23, 2007

okgat said:
Would someone please explain again, where the stresses occur that cause failures. Rick G.

Tractors with 3pt backhoes most ofter break in the clutch area. Think of the whole tractor/hoe as a lever with the fulcrum at the rear axle/outriggers. When working the backhoe sometimes can lift the front of the tractor off the ground. The backhoe is strong enough for this and usually the rear axle is also as it is designed for carrying/pulling loads beyond the tractors own weight. The tractor front axle is also usually designed for extra weight as evidenced by weight bars that can be added for plowing etc. The midpoint of the frame will carry those loads but with backhoe operation the the forces suddenly increase/decrease & reverse direction. The clutch area being the weakest is usually where failure show up it it's going to. A subframe mount usually reaches just beyond the clutch area & reinforces it. The other areas of potential failure are also reinforced by the rigidity of the subframe spreading the forces over multiple points of attachment, more so than a 3pt mount. Look at most FEL mounts, especially the older ones. None rely on the tractor clutch housings for strength, all carry some rigid structure from the front axle to the rear axle. Also look at industrial tractors, all have an independant (steel - not cast) frame for loader /backhoe attachment. MikeD74T

BobG_in_VA · Mar 23, 2007

okgat said:
I
On my 2910, the lift arms are connected to the tractor on each side at the bottom of the rear axle and the center link is then connected to the upper mid bracket. Would someone please explain again, where the stresses occur that cause failures. I ask this because the brackets beneath the rear axle seem "beefy".

Thanks,

Rick G.

The greatest stress point is the Upper mid bracket. I've got a friend with a 1900 Ford that he uses a 7500 Woods 3pt BH on, He broke the mid/toplink braket off the tractor when he was working the hoe...had to find a GOOD welder to fabricate another on to bolt back on. BobG in VA

okgat · Mar 23, 2007

Rob and Mike I want to thank you for your explaination, it helps a great deal.

Rob, if you have a chance, would you post your pictures.

In summary, what I believe I understand is that the backhoe causes stresses at the clutch area beyond what the tractor can take. By the way, the old backhoe I bought is well over 600 pounds, I imagine probably closer to 1000-1500 pounds.

The cure is to attach a subframe, first near the front mount of the bucket attachment along the bucket frame rail and then at the bucket frame rail at the rear axle using longer bolts.

Thanks again for your input,

Rick G.

okgat · Mar 23, 2007

Thanks for your information Bob G. I am going to have to come up with a design that eliminates using the mid point connection or reduces the stress so I don't have the same problem.

irwin · Mar 23, 2007

I've got my subframe almost ready, but thanks for the woods tip.. it's nice to see I'm doing it right--well better it seems then woods would.... 4 -1/2" bolts, 4 7/8" bolts and 2 7/8" pins.. might take a few minutes longer to mount and dismount.. but it cost me appros. $300-320 in material? the 6"x6" 3/8" x 4' angle pieces were free

okgat · Mar 23, 2007

Irwin, if you have chance, would you please post your finished product also. I would be interested to see how you have fastened the subframe to your tractor (at what points) and how again it is fastened to the backhoe.

I have looked at the Wood's site and it provides great information, but photographs of your project would be a great addition.

Thanks,

Rick G.

MikeD74T · Mar 23, 2007

okgat, Found the pics of my Long backhoe adaptation. Marginal quality pics! Previously I had the backhoe on a Ford 801. The adapter for that was essentialy a loader frame extension, 3x4x1/4' tubing, beyond the rear axle. It removed from the tractor with four 1" bolts. Welded tabs on the loader frame near the clutch area with matching tabs on the extension, and the rear had tabs on the extention that mated with spare holes in the loader brackets under the rear axle. The extension bolted rigidly to the loader frame which in turn hung from the tractor, attached at the front & rear axles. That subframe extension was welded directly to the hoe 3pt frame. Took about 1/2+ hour to mount/dismount. Woods subframe is bolted to the hoe, 5 minute mount/dismount. MikeD74T

okgat · Mar 23, 2007

Thanks Mike very much. The photos help a great deal with my being able to understand how to put it all together. I would like to thank all of you very much for your assistance. Believe it or not, I am starting to come up with an idea that incorporates a lot of what I have learned from this thread but also from the other threads that I have read.

Let me pass this by you and see what you think. The basic concept goes something like this:

1) I weld either square or rectangle brackets beneath the bucket frame (underneath each rail) starting towards the front and gong to the back at several spots. Lets say 3 spots. Forward, midway, then in the area of the ROPS bracket.

2) I take two pieces of square or rectangle 1/4" tubing (that will be inserted in the brackets in #1) out to where the tubing meets where the two legs of the 3 point hitch would have mounted.

3) I weld onto the end of each tube a 3 pt fitting so that pins can be installed on the two legs of the backhoe attachment.

4) I weld on a square frame that is braced from the two rails up to meet the top of the square frame (for support) and weld on a fitting that will accept the mid point connection. This way I can connect to the bracket from the backhoe upper link with a small length of steal 2x2".

5) With this all accomplished, I then slip the entire unit into the bottom of the bucket rails and pin it in place. Once pinned in place, I then attach the backhoe.

Okay, what do you think? Do you think this will work? Input please!

Thanks,

Rick G.

jarokoro · Mar 23, 2007

ALCON,

Here are the pictures I promised. Notice the complete sub-frame on the pallet. The A- frame portion swivels on the rear cross member. The tractor Sub-Frame brackets consist of 2 rails from loader mount to rear axel and then 2 hanger brackets on the rear axel housing. (I bought the BH from a guy that had his tractor stolen. So it was cheaper to by the bundle install kit for the BH $1085.00 than the four brackets; $1205.00 just for the two rear hangers and 2 frame rails no fasteners, shields etc…) So I guess I will build something and use this BH sub-frame as a mount; I was thing about a PTO run stump grinder.

okgat · Mar 24, 2007

Thanks Rob for taking the time to load your photographs. Your photos helps in narrowing down how I shall proceed. That subframe is really substantial.

Thanks again,

Rick G.

MikeD74T · Mar 24, 2007

okgat, That's almost exactly what I did when the backhoe was on my Ford. The only difference - my backhoe was welded to the subframe rather than 2 pieces. I expect your plan will work very well. One thing to consider about a 2 piece design -with a one piece once the hydraulic hoses are hooked up you can use the outriggers & boom/dipper to position the unit when mounting/dismounting. With a two piece you may have to muscle the 1st piece by hand, although you may also just leave it on the tractor. Consider also that any "slide-in" or telescoping arrangement requires precision measurement & fabrication. Slight warpage from welding can cause installation nightmares. Good luck & SEND PICS of your progress. MikeD74T