I just bought this 7100 and the previous owner attached the backhoe. Is this set up correct? What should I look for or consider when attaching to the 3point? Backhoe model 4520B
B7100 Backhoe setup…. Is this the correct way?
- Thread starter Benedict
- Start date
Lil Foot
Well-known member
Lifetime Member
Equipment
1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
Can't help either.
That is not a B670, the usual subframe mounted hoe that B7100s most commonly have.
Hopefully someone smarter than me will chime in.
That is not a B670, the usual subframe mounted hoe that B7100s most commonly have.
Hopefully someone smarter than me will chime in.
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
That's a Kubota-badged Woods BH650. Here is the Woods manual for their version:
Kubota sold them for use with the B9200 and a variety of L series tractors. I don't think it was ever supposed to be paired with the B7100. The 3ph mounted backhoe for the B7100 is the B4672.
The pictures I've seen of the Kubota mounts for your backhoe do not use the 3ph lift arms. The arms are replaced with a frame to the tractor. I'm guessing they wouldn't fit the B7100, hence the mishmash of brackets holding yours on. Frankly, I don't like what I see in the pictures.
The B4672 mounting brings the backhoe closer to the rear of the tractor. The upper 3ph mounting bracket on the tractor is replaced by a heavy duty version designed to better distribute the load (pictured in Lencho's second image). From what I can see in your picture, you still have the standard bracket installed.
If you look at Lencho's 1st picture, you can see the single heavy "mast" that connects straight from the BH to the new HD upper 3ph mount using TWO mounting pins. The diagonal bracing runs between that ridgid bar and the bottom of the backhoe on either side. It is very rigid. The lower lift arms of the 3ph do not actually support any weight, they are merely used as bracing.
Your setup appears hinged on a single bolt in the middle. It appears your lower arms are used to support the weight of the backhoe. Quite frankly, I think your setup could damage the tractor's castings. I certainly would not try to use that backhoe without the heavy duty top link bracket.
If you look at page 10 in the manual listed above, you can see that those two upper pieces are supposed to overlap, forming a single straight and rigid section held rigid with bolts through two holes. The resulting mast should be pinned to the uppermost top link hole.
If possible, I would move the lower lift arms to a hole closer to the backhoe so as to bring the backhoe closer to the tractor. I think you might need to flip the pins to the inboard side of the backhoe to do so. And the diagonal bracing should be angled to a hole in the mast as close as possible to the tractor for best effect.
The HD bracket is very difficult to find these days. I made my own using 1/4" plate for the main part and 3/8" flatbar for the actual top link mount holes:
The backhoe sits low and very close to the tractor.:
Good luck!
Kubota sold them for use with the B9200 and a variety of L series tractors. I don't think it was ever supposed to be paired with the B7100. The 3ph mounted backhoe for the B7100 is the B4672.
The pictures I've seen of the Kubota mounts for your backhoe do not use the 3ph lift arms. The arms are replaced with a frame to the tractor. I'm guessing they wouldn't fit the B7100, hence the mishmash of brackets holding yours on. Frankly, I don't like what I see in the pictures.
The B4672 mounting brings the backhoe closer to the rear of the tractor. The upper 3ph mounting bracket on the tractor is replaced by a heavy duty version designed to better distribute the load (pictured in Lencho's second image). From what I can see in your picture, you still have the standard bracket installed.
If you look at Lencho's 1st picture, you can see the single heavy "mast" that connects straight from the BH to the new HD upper 3ph mount using TWO mounting pins. The diagonal bracing runs between that ridgid bar and the bottom of the backhoe on either side. It is very rigid. The lower lift arms of the 3ph do not actually support any weight, they are merely used as bracing.
Your setup appears hinged on a single bolt in the middle. It appears your lower arms are used to support the weight of the backhoe. Quite frankly, I think your setup could damage the tractor's castings. I certainly would not try to use that backhoe without the heavy duty top link bracket.
If you look at page 10 in the manual listed above, you can see that those two upper pieces are supposed to overlap, forming a single straight and rigid section held rigid with bolts through two holes. The resulting mast should be pinned to the uppermost top link hole.
If possible, I would move the lower lift arms to a hole closer to the backhoe so as to bring the backhoe closer to the tractor. I think you might need to flip the pins to the inboard side of the backhoe to do so. And the diagonal bracing should be angled to a hole in the mast as close as possible to the tractor for best effect.
The HD bracket is very difficult to find these days. I made my own using 1/4" plate for the main part and 3/8" flatbar for the actual top link mount holes:
The backhoe sits low and very close to the tractor.:
Good luck!
Lil Foot
Well-known member
Lifetime Member
Equipment
1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
A couple of other details:
The HD top link bracket from Kubota is part number 70050-93214
ANY backhoe REQUIRES installation of a Front End Loader with subframe!!! I can't stress this enough. You will break your tractor in half without a subframe running from the rear axle to the front bumper with attachments to the transmission housing and rear of the engine. The castings are just bolted together and are not strong enough to take the stresses without reinforcement.
The HD top link bracket from Kubota is part number 70050-93214
ANY backhoe REQUIRES installation of a Front End Loader with subframe!!! I can't stress this enough. You will break your tractor in half without a subframe running from the rear axle to the front bumper with attachments to the transmission housing and rear of the engine. The castings are just bolted together and are not strong enough to take the stresses without reinforcement.
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
One last thing: the B4672 has an additional brace, not included with your backhoe, that further limits stresses on the 3ph. It doesn't actually bolt to the tractor itself, but it does exert leverage on the underside of the lower lift arms when taking the weight of the BH. I wonder if something similar could be retrofitted to your backhoe:
Lil Foot
Well-known member
Lifetime Member
Equipment
1979 B7100DT Gear, Nissan Hanix N150-2 Excavator
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Thanks, but Kubota did most of the writing. I was mostly posting limited excerpts for educational purposes and private study. ;-)
@Lencho, @torch, @Lil Foot I want to thank you for taking the time to help me with this setup. I need to digest the info a bit and try to find the reinforcement top bracket, there is one posted for sale in the classified forum so I contacted that member.
The Tractor does have a FEL with the stock subframe, I hope that subframe is enough to distribute the load and I don't also need the second subframe shown in the above illustration, its discontinued, ill have to see how far back the FEL subframe goes but something tells me that it does not go to the rear axle.
Do you guys think I can make this setup work with what I have if I add the 3pt top bracket or do I need to find that top mast that's shown in @Lencho photos?
Thanks again
The Tractor does have a FEL with the stock subframe, I hope that subframe is enough to distribute the load and I don't also need the second subframe shown in the above illustration, its discontinued, ill have to see how far back the FEL subframe goes but something tells me that it does not go to the rear axle.
Do you guys think I can make this setup work with what I have if I add the 3pt top bracket or do I need to find that top mast that's shown in @Lencho photos?
Thanks again
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
How are your metal fabrication skills and facilities? You don't necessarily have to buy Kubota's subframe if you can weld up a functional equivalent. That's what I did when I built my FEL. The subframe is merely some heavy metal reinforcements running under the tractor.
I suspect that you do not need to buy Kubota's mast. I believe that you can make your stuff work -- if you configure it as shown in the Woods manual: resulting in a straight piece formed by overlapping the two sections you have and bolting them together using at least two sets of holes. I'm not certain about the length of the diagonal braces -- they may be a bit too long. But if so, the material can be cut down to size and new holes drilled as required.
Let's put it this way: I'm pretty sure I could make it work. You are the better judge of your capabilities. If this seems daunting, you may need to seek some assistance.
I suspect that you do not need to buy Kubota's mast. I believe that you can make your stuff work -- if you configure it as shown in the Woods manual: resulting in a straight piece formed by overlapping the two sections you have and bolting them together using at least two sets of holes. I'm not certain about the length of the diagonal braces -- they may be a bit too long. But if so, the material can be cut down to size and new holes drilled as required.
Let's put it this way: I'm pretty sure I could make it work. You are the better judge of your capabilities. If this seems daunting, you may need to seek some assistance.
It just depends on your risk factor of how much you have invested so far, and if the backhoe breaks the machine in half what your loss will be. I am not much of a gambler, so I wouldn't take that risk unless I bought the unit so inexpensively that I knew that I could part it out and get my money back. Always best to take the picture prior to purchase and ask in advance rather than spend money on a machine that has been cobbled together by someone who didn't understand the stresses that a backhoe can put on a tractor.
Well this was bothering me so I ran home real quick to check and the subframe of the FEL does connect to the rear axle so that's good I suppose.
I am pretty well equipped to Fab, its not a daunting task to me, I am just trying to develop the scope of the task at this point.
Seems to me given that the FEL subframe runs back to the rear axle that I am covered on that front. I need the heavy duty top 3pt bracket (or make my own) and reconfigure the top brace to use two bolts and have it connect in a straight line to the BH from the top 3pt bracket.
Should the 3pt hydraulics be fully lowered when the BH is attached?
torch
Well-known member
Equipment
B7100HSD, B2789, B2550, B4672, 48" cultivator, homemade FEL and Cab
Yes. You might need to lift the arms by hand a bit to make the connection, but they should not be raising the backhoe. That is all spelled out in the manual I linked to, above. Pages 10 to 13 give pretty detailed instructions on attaching the backhoe to the tractor. It does mention needing a minimum of 11-1/2" between the top link connection and the lower arm pivot. I measure my tractor to have 14".
So by the sounds of it, you only need to source or fabricate the HD toplink bracket and you are good to go.
Hi Benedict,
Torch has dome a great job of calling out the issues and I suggest you take his advice. The bolt in your current attachment locks like it will swivel under pressure. Fab up a two point connection at the upper end and make sure your FEL has a brace to the lower end as well and you should be good to go!
As Animal45 said, the shields on the booms are unique and I think pretty cool!
Update us with your progress.
Torch has dome a great job of calling out the issues and I suggest you take his advice. The bolt in your current attachment locks like it will swivel under pressure. Fab up a two point connection at the upper end and make sure your FEL has a brace to the lower end as well and you should be good to go!
As Animal45 said, the shields on the booms are unique and I think pretty cool!
Update us with your progress.
Donystoy
Active member
Lifetime Member
Equipment
LX2610HSDCC, B/H, Loader, plus numerous other attachments. B7200 sold
Here are pictures of the subframe that I built for the B7200 that I had. It brought the hoe about six inches closer to the tractor.
Attachments
I just wanted to thank everyone for their input and wisdom. I got the 3pt set up correctly and ordered the correct HD top link bracket from Kubota (ouch$$). Used the hoe to dig a trench with ease.