To 3PT or to subframe, just the facts.

[skipro3]

Thanks for all the info!

So, now with the impression of a stronger set-up; has anyone ever damaged their tractor using the 3PT? I'm just trying to find out if there's anything to worry about in that regard. My ground is pretty rocky and I'm new to tractors and backhoes. With that said, I spent 3 hours on it today practicing digging a ditch, then filling it in again. When I hit a rock and catch it with a bucket tooth, the tractor will lift off the ground. I can't see where this will be any more stress than if I were to use any other hydraulic jack to lift my tractor, like a floor jack for example. The most stress can only be that of the weight of the tractor. After that, the tractor lifts and the load stress is maxxed out. Maybe I'm wrong with that logic so jump in and correct me please. Now, if I were to, say, strap or chain down the back hoe to anchor points attached to the earth, then tried to dig rocks that would put extra strain on the 3PT hitch, I could see where the stress will have exceeded that of just lifting the tractor off the ground.

Also, my personal observation is that the backhoe isn't near as powerful as the front end loader. I can pick up huge rocks with my FEL where-as an average size rock will stall my hydraulic ram for any of the levers on the hoe. Maybe I'm not doing it right.

 

[AndyMA]

Thanks for all the info!

So, now with the impression of a stronger set-up; has anyone ever damaged their tractor using the 3PT? I'm just trying to find out if there's anything to worry about in that regard. My ground is pretty rocky and I'm new to tractors and backhoes. With that said, I spent 3 hours on it today practicing digging a ditch, then filling it in again. When I hit a rock and catch it with a bucket tooth, the tractor will lift off the ground. I can't see where this will be any more stress than if I were to use any other hydraulic jack to lift my tractor, like a floor jack for example. The most stress can only be that of the weight of the tractor. After that, the tractor lifts and the load stress is maxxed out. Maybe I'm wrong with that logic so jump in and correct me please. Now, if I were to, say, strap or chain down the back hoe to anchor points attached to the earth, then tried to dig rocks that would put extra strain on the 3PT hitch, I could see where the stress will have exceeded that of just lifting the tractor off the ground.

Also, my personal observation is that the backhoe isn't near as powerful as the front end loader. I can pick up huge rocks with my FEL where-as an average size rock will stall my hydraulic ram for any of the levers on the hoe. Maybe I'm not doing it right.

Much of what you read on this site is antidotal evidence ( just based on people's hunches and experiences). This type of information although interesting is not the type of informationtion engineers like myself usually rely on. This thread is particularly bad in the false information that it is spreading. A subframe spreads the forces from the backhoe most of the length and reinforces the monoframe (engine, tranny, differential) against the tortional (rotational) forces that a backhoe exerts. It also reinforces against several other forces that you need to draw a "Free Body Diagram" to see. The forces a backhoe exerts are many time the forces a loader can generate. A loader is also usually much more integerally tied to the tractor frame. For example, my Woods 1050 can rip at 6500 lbs at the end of it's bucket teeth. Properly positioned this can be multipled by the 11 foot lever arm plys 2 foot bucket lenght of the backhoe and create tremdious forces. Without doing the math, I would expect that a full length "grab" at 90 degrees from center (in other words fully off to the sides) might be expected to inflict close to the maxium rotational force on the tractor. Personally I would like to distribute that force to as many points as possible. A subframe has some long lever arms of it's own that also help out nicely (particularly when fully out straight back. The forces at the front of the subframe where the subframe arms are acting as levers will be diminished substancially deoending on where the relative fulcrim points are located (think see-saw. Add to this the shock loads and many other factors and the subframe is just much more gentle on the tractor.

Just a few of my late night tired thoughts, others jump in and correct me where I'm wrong. Now just a little bragging... The only 100 I ever got on a final was in Statics, that was 35 years ago so I'm sure I'm a little rusty, but by now I've seen many designs that work and also others that don't. Just remember that just because your's didn't break, doesn't mean that 10 others didn't.

Andy

 

[Rara Avis]

Even with a frame a tractor can fail...read this thread and check the pictures...
http://www.tractorbynet.com/forums/attachments/81587-arps-backhoe.html

 

[skipro3]

Just remember that just because your's didn't break, doesn't mean that 10 others didn't.

Andy

That's my point and my main question; are there any 3PT backhoe attachments that have broken their tractors? I've heard of it, read talk of it. But always seems to be "my brother's cousin's sister's uncle" that the story was heard from. No first hand experience?

I find it incredible that the design has been out there so long that:
1. The manufacturers of tractors would design and sell their own model to go with their tractor if they are prone to damaging the tractor.
2. That manufacturer of tractors would not immediately void warranty if a backhoe of any size were attached to their tractor of another make/model.

 

[marksmu]

I have not owned either. In fact Ive only used a rented mini excavator for what I do....but I just bought (delivery in 5 more days) a Rhino 3pt mounted backhoe.

Its alot of backhoe, but Im mounting it to a lot of tractor. From what I hear the biggest problems come from pushing up on the 3pt linkage, not pulling down. The linkage is designed for the downward pressures, but not the up. There are few implements that push up, and a backhoe can push up as well as pull down.

With that said, I choose 3pt over subframe for 2 reasons. First the subframe was not available, and I would have to make my own, and second, for the amount I use the backhoe (6 times a year to deepen silted ditches and close up fields to flood in the winter) the 3pt probably wont see the stresses that people who use them constantly see.

We will see soon though.

 

[jpm]

skipro, i had a 3pt hoe on my old tractor that broke the top link mount from ?
also on my set up i had to put my body parts in danger to hook it up & it was a pain in the --- .the manufactor came out with a 4 pt mount 1 1/2 years later. i put one on much easer & safer .the manufactor now only sells 4 pt and does not warrent 3 pts.of course my new tractor has a 4 pt hoe

 

[Cyberroc]

Many different backhoes, many different tractors. If your Backhoe is matched to your tractor, you will at least be better off than if you got one that is too strong for your tractor, regardless of the mount.

While I find it funny that you ask the question and then either because you don't understand it or don't like the answers you are getting; you keep trying to show cause that the 3pt is just as good or better than a frame mount.

For a tractor mounted backhoe, a well designed frame mount is better for your tractor than a well designed 3pt. (with no frame support), in that a frame mount will be able to take (or disperse) more force than the same Backhoe on a 3pt. You wanted facts, there it is. I have thousands of hours on both, I am an engineer, and I stayed at a holiday inn express. Ok, I did not really stay at the holiday inn express, however the others are true.

Now does this mean your purchase was a bad idea or does this mean you should never own a 3pt backhoe? No.

In the right application they are fine, we had a 3pt that we used for many years without any major issues. While it did not see as much work as our Frame mount and it was not used for the heavier jobs, it did fine at what it was purchased for.

Truth be told, a dedicated backhoe setup is better than any tractor mounted backhoe, and so on. I own the frame mount, however I am also smart enough to know when I need to rent a dedicated backhoe for a job that mine is not intended for.
.
.

 

[Bedlam]

I had a problem with mine first time in 28 years of use on two different Fords. the wood back hoe ripped the top link bracket on the tractor off. &5 dollars fix. I only hope that the new one isn't any stronger, as i look at the bracket more now as a 'shear bolt' . I'm glad it gave before the frame. (this is 3 PT hitch no sub frame)
Now the fact, I had the solid mounting struts on it not bolted together, (this bracket keeps the links solid and no movement up or down).I was digging deeply under a stump, I was making the problem that it ripped, As no force was transmitted to the lower link and onto the stabilizers.
I was clearly at fault here.
Looking back, it was a lucky and cheap mistake.
I would say allot depends on the amount of tough duty you put on the machine.I remember how i really pushed the woods far further than I would be comfortable with now after seeing pictures and seeing how the tractors are bolted together etc.
I have considered a larger hoe for this tractor, and the brochures indicate it can be done, however I believe it would be marginal. Id pref ere a subframe in the future..myself.
But for light duty, 3 PT is fine.Naturally what is light duty is all relative.
But I agree, the consensus seems to be dead set against the 3 PT hitch type.

 

[brandoro]

As you might notice in my avatar, I have a 3pt mounted BH. It is a small Landpride, digs 6.5' deep max, has a 10" wide bucket. It also has a bracket that bolts to the drawbar with adjustable links to the BH. The drawbar now carries virtually all the weight and upwards and downwards forces along with a fair amount of push/pull. With this arrangement and the small size of the BH I really don't have a concern that that BH will hurt the tractor.
I have never used a frame mount so have no opinion as to which is better.
The B7610 has 220 hours on it now, about half of that was with the BH attached and in use. So far BH use has been digging around the foundation of my house for weeping tile, trenches for drainage and a couple of short trenches for sewer and water. There are a few stump removals in the future.

 

[dfkrug]

1. Most people posting that the subframe is the better don't own a backhoe.

2. Of the people who do own a subframe mounted backhoe, most, if not all, have never owned a 3PT mounted backhoe.

3. People who own 3PT mounted backhoes speak well of them.

I'm gonna go out on a limb here and say that the 3PT mounted backhoe is as good as the subframe mounted backhoe.

SKIPRO, aren't you falling into your own trap? Many members of TBN will
pontificate on various subjects without the experience to back it up. Every
one needs to separate the wheat from the chaff themselves, though many
TBN members will help!

That said, I have used the same backhoe on a 3-pt hitch on one tractor,
then on several other tractors using various types of subframes. Many
hundreds of posts are on TBN extolling the virtues of a subframe, and I
concur with most of them. The advantages of using the 3-pt hoes are:
> they are cheaper than subframe attachments
> they fit most tractors
> they usually go on and off faster
> they sometimes have more ground clearance

On the one 3-pt setup I used, the hoe was mounted 12 or more inches
farther to the rear than all of my custom subframes, but it was about
as far rearward as the one factory subframe I installed. Mounting closer
to the tractor improves ground clearance and stability.

Also on the subject of experience: I have never broken or seen first hand
a tractor that was broken by a hoe attachment. Sometimes you CAN learn
from the experience of others. I like to try a lot of things myself, but
breaking a tractor is not one of them.