Backhoe Backhoes & 3 point connections

   / Backhoes & 3 point connections #1  

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I have a (new) Kelley 600 back hoe on my Kubota 7500 (21 hp). When it is working, it works well. I this week I dug out this HUGE stump, pushed/pulled/nudged it up an incline with the backhoe and FEL (with lot of time spent to get it done safely) to dump the stump in a fill area (future barn site). Saved me HOURS of time and money!

However I have mixed feelings about the backhoe unit. One cylinder leaked oil within 3 hrs. Took 3 weeks to replace it (warranty). Today, another leak (about 10 hrs on unit), different cylinder, same place (near weld on the bottom of cylinder).

In addition some of the Kelley 3 point mounting brackets (mounted on draw bar) are slightly bent (as if the plate wasn't thick enough) right over the turnbuckle.

To compound things, the backhoe hydraulics run off the tractor pump, so when one of the hoe's cylinders is fully extended and one doesn't back off the lever fast enough, a hydraulic "surge" is felt through the tractor causing the 3-point to raise about 1/2 inch. Dealer says this is "normal."

I have a feeling this hoe & perhaps my tractor isn't going to last if these conditions continue.

Is this my "penalty" for not choosing a sub-frame and/or PTO mounted hydraulic pump? Or this brand of Backhoe?

Any comments appreciated, even if brutal!!!
 
   / Backhoes & 3 point connections #2  
If I perceive your comment correctly, do you really want to use a stump in a fill area your going to build over? Won't that just rot away over time and create a depression?

Hopefully, I misunderstand (imagine THAT!!) and your buring it or other?

As I don't own a tractor /w3tcompact/icons/frown.gif, I can't comment on the 3-point question.

Richard
 
   / Backhoes & 3 point connections #3  
Well, I think this is the classic argument of the 3PH mounted vs. the subframe style of BH. You may be overdoing it on the 3PH. Personally, I would lean toward the subframe style.

Also, I would heed what Richard said about putting a stump in a fill area that you're planning on building on. Not a good long-term plan.

The GlueGuy
 
   / Backhoes & 3 point connections #4  
W, I have not had any problems with much use of my Kubota 3pt backhoe with PTO pump.. Run a search on backhoes with sub-frame and 3pt and you can get more info than you can take in. And not good form to bury organtic under foundations.
 
   / Backhoes & 3 point connections
  • Thread Starter
#5  
Richard, glueguy and Jag,

Well, I did learn a few things about burying stumps! Thanks!

Prior to buying my Kubota (and backhoe) I reviewed a considerable amount of information about my tractor (and backhoe) from this website, which certainly helped me make smart decisions along the way.

I understand ongoing subframe vs 3 point debates being carried out at this excellent website. But it seems to me there is something not quite right with the 3 point set up here.
 
   / Backhoes & 3 point connections #6  
It sounds like the structural issues are on the BH, not the tractor? I'm one of the people who believes 3PH BHs are fine as long as they are properly rigged. To that end let me ask....

1) Did you install the Kubota special 3PH top link brack on the top of your transmission case?

2) Did you install the Kubota frame reinforcement braces that run from the outer sides of the transmission to the loader subframe?

If not, then I think you risk damaging the tractor and you should install these before using the BH any more.

As for hydraulics, I don't think using the tractor hydraulics will make any difference in the surges, as you describe them. I had a Woods 6500 3PH BH on a B2400 and the tractor did lunge around a lot when working it hard. I now have a 2910 with 4690 BH and it lunges around much less. I attribute it all to the tractor being bigger and heavier since the power of the two BHs is very much the same. I think you can expect the 7500 to get knocked around a bit by the backhoe.

<P ID="edit"><FONT SIZE=-1>Edited by hayden on 05/14/01 08:37 PM (server time).</FONT></P>
 
   / Backhoes & 3 point connections
  • Thread Starter
#7  
Hayden,

The way the Kelley backhoe is attached is by using the "stock"
Kubota top link and the two lower link arms. A bracket plate is then attached to the drawbar and two more "links" are attached to that and the backhoe, in effect making it a "5-point" connection.

The Kelley dealer is also a John Deere dealer and says the backhoes go on the Deeres the same way as my Kubota. I have yet to hear about special mounting brackets as you mentioned. (I shall contact Kubota and ask about it.)

The Kelley dealer did call the Kelley factory (today) and found out that Kelley has since "re-engineered" that (bent) part that mounts on the draw bar (for the B-600 series) and are going to rush me that part and replacement cyclinder. They believe this will resolve most of my problems.

I shall wait till the new part is installed and report back here and give a status report. However, I'm inclined to agree with you that the Kubota 7500, being small, will get jerked around a lot.

(PS: As for the Kubota 7500 -- it has 50 hard earned hours now and not one thing wrong with it! Worth every penny!)

Thanks.
 
   / Backhoes & 3 point connections #8  
I'd strongly suggest getting the Kubota reinforcement brackets and installing them, as a precautionary measure if nothing else. I also think it will put you in a much better position if anything should break or get damaged on the tractor itself by showing that you took all steps to rig the tractor properly.

Without seeing the Kelly setup it's hard for me to assess whether/if the structural loads on the tractor woudl be different from those for the Kubota BH, but the extra braces are intended to reinforce the tractor as follows. You can judge whether the Kelly setup elimiated the need for the braces.

TOP LINK: The BH puts much more load on the top link where it anchors to the trans case that a "passive" 3PH attachement. The stock 3PH top link bracket is just two angle brackets with 2 bolts each into the back of the trans case. Looking at it, you can see how an excessive load pulling on the top link could just rip the bolts right out of the case. The reinforced bracket is one solid piece and it wraps up over the top of the case and bolts on the same 4 rear locations, plus 4 more on the top of the trans case.

LOWER FRAME BRACES: There are two, one on each side, and they bolt to the trans case on the underside near where the axels come out of the case, and then to the loader subframe about in the middle of the tractor. This creates two side stays that take side to side loading on the tractor frame. Under normal operation, there aren
t many forces trying to fold the tractor in half like you would fold a mattress, but the BH, especially when digging out to the side, will exert significant latteral loads. The braces halp take this load.

Granted I haven't seen how the Kelly mounts, but I can't imagine these same loads are not still present.

My 4690BH manual also covers the 4672 and is calls out PN 70050-00540 for the top link bracket for the B7500. I don't have a source for the PN for the lower braces. They are standard equipment on the 2710 and 2910 models.

Good luck,

Peter
 
   / Backhoes & 3 point connections #9  
Peter, I have a 2910 and have been contemplating the backhoe addition since I bought the tractor. First, I'm wondering if I'll get $5-6K worth out of it (probably would pending the next few questions). Second, I'm concerned about how the structural (e.g. subframe) additions will affect other tractor operations. Third, I still wonder about how much real work a 3pt backhoe can really do. I'd buy the Kubota unit I'm sure. Any feedback from you would certainly be appreciated.

Thanks,

Larry...
 
   / Backhoes & 3 point connections #10  
The Kubota frame members don't interfere at all. Your 2910 already has the under-frame braces and you can see them by peeking under. The 3PH anchor is completely compatible too.

The Woods frame, on the other hand, interferes with an underbelly mower so take that into consideration when selecting.

As for work, I've been quite pleased with the 4690. I've put in an 80', water line (3' deep), several culvert pipes, done trenching, dug out monster rocks, etc. When I had the woods 6500 on my B2400 I dug out a bunch of stumps, including one that was much bigger than the tractor, and I dug the foundation for my barn. The 6500 was noticable small and required very exact positioning to reach the "target" and lots of moving to stay on target. The 4690's extra reach makes a huge difference, even though it's still only 7 1/2 feet, but that extra foot seems to make the world of difference.

As for cost effectiveness, I'll have to leave that one to you. I justified mine based on conveninece and fun much more than cost of hiring out the work, but I suspect after 5 years or so I will have covered that too. And I get a great toy in the mean time.

Mountain bikes and tractors - both excused to go play in the mud/dirt again. I have both.
 
 
 
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