Backhoe 3930 3-Point Backhoe Attachment Damaging Draft?

[Bumblebeer]

I recently purchased a 3-point backhoe attachment to go with my 3930. I know 3-point backhoes get a lot of hate, and are generally inferior to sub-frame mounts. However, due to my particular situation, I feel like the 3-point mount is the best choice for me. I'm saying this cause I'd like to prevent this thread from becoming another 3-point vs subframe backhoe debate.

The tractor has a loader on it, and I feel comfortable with the load distribution across the engine, trans, and diff connections. But I'm concerned with the amount of force the outriggers, and digging action will be putting on the draft cylinder. Of course I set the position and draft levers all the way to the bottom when the backhoe is attached, but I wasn't able to find any specs on how much force the draft system is designed for, anyone have some info, or experience with this? I'll be using this for fairly light work digging in sandy soil. No digging rocks or stumps.

If this is a problem, my current solution is to purchase a different toplink bracket. My current bracket only has one bottom pin hole (pictured below).

I was thinking I could buy a bracket like the one below that has two bottom pin holes and put a pin through each hole when the backhoe is attached, this should minimize the force being applied to the draft system. Would this be fine to also use when plowing when I want to use the draft if I just remove one of the two pins, or would I need to swap the whole bracket? I also know that I can attach the backhoe to the bottom of the two holes on the toplink bracket and that would apply less force to the draft system without needing to buy a new bracket, but I don't know if that would be adequate. Thoughts?

 

[ptsg]

You're spot on about the hate on the 3pt backhoes.

If anything, the bracket will work as a fuse and may break instead of the much more expensive rear end housing like usually happens on tractors without draft control.

Around here, 3 pt backhoes with a PTO pump are used quite a bit. There is absolutely no sub frame backhoes available as I believe, like the loaders, those are made for the US only.

What the dealers will do, is adding two additional top links that will connect to two brackets that were previously welded or bolted on the two ROPS posts or at the base of the ROPS posts on top of the rear axle housings. This will weld distribute the load to more points on the tractors, instead of concentrating everything on the top link mount. This also allows the stabilizers to lift the entire tractor and not just push the 3 pt up.

Tried to find some pictures to illustrate what I'm trying to explain. Hopefully you get the idea.

On the other hand, a 3930 is a lot bigger/stronger than any of these SCUTs or CUTs where you often see damaged housings. Unless you're running a crazy oversized backhoe, it will probably be just fine but it's better be safe than sorry.

 

[jimglassford]

There is a reason Ford did not build a backhoe attachment for this AG tractor. The draft control is designed to handle force in one particular direction where a backhoe will apply force in both directions. The manufacturer will never release specifications for uses outside of the design envelope.

So what you really are asking is that you know a three point backhoe can damage the draft control but can you get away with it? Maybe or maybe not

 

[Bumblebeer]

There is a reason Ford did not build a backhoe attachment for this AG tractor. The draft control is designed to handle force in one particular direction where a backhoe will apply force in both directions. The manufacturer will never release specifications for uses outside of the design envelope.

So what you really are asking is that you know a three point backhoe can damage the draft control but can you get away with it? Maybe or maybe not

I appreciate your response, however, you are incorrect about the functioning of the draft control system in this model of tractor. The 3930 (which corresponds to model # 4110 in the manual I have) has a double-acting draft spring designed to sense compression and tension.

I can understand Ford/New Holland not seeing a need to publish the load ratings for the draft system as it was obviously not designed to operate with a backhoe, and it's very unlikely for an operator to exceed the draft load limits during typical plowing. However, I have to think that the tractor was designed with the idea of it being used in a situation where the draft control may be at risk of damage. Otherwise, I don't see why there would be a toplink bracket that can be made not to pivot since this would prevent the draft system from functioning.

I do realize there is a possibility of a 3-point backhoe damaging the draft system. That is why I created this post to get ideas on how it could be minimized if it is a serious concern. I like the suggestion from @ptsg. Baring any further suggestions, I think I will use a two pin toplink bracket so I can lock out the draft control cylinder as well as install a couple of additional toplinks mounted to the ROPS. I'll update this thread when the work is finished and I've had a chance to test it out.

 

[RickB]

I had a Woods BH90-X fitted to my Ford 3cylinder 4000 via the 3 point. When I bought the hoe at auction my local New Holland service manager (my supervisor at the time) told me about a service bulletin (from Woods if I recall) that listed a couple parts that get installed in the draft control spring of the tractor to completely disable the draft signal to the hitch valve.
That was years ago and all the details escape me, but there is a clue for you. I had great success with that tractor/backhoe combination but have seen both top link rockers and rear differential housings on similar sized Fords broken by misuse of similar equipment. It's all up to the operator.