LW-7 BH

[traktorz]

Apr 21, 2010 15:35:59 GMT -5 red said:

Traktorz, If I knew what I know now I would not have brought a Chinese Backhoe. (Both Ranchhand and Affordable DON'T sell them) The Korean and Italian backhoes are much better products for not much more money.

Cheers red,

but we're aware of the well referenced Italian Moris backhoes as well as the NorDigg backhoes (which has Swedish Parker Hannifin hydraulic cylinders & Italian Moris valve unit, but the NorDigg mainframe still is of Chinese manufacturing), that both are sold in Sweden, but not in the Chinese budget class. Regarding Korean LITW backhoes, I'm not aware of if we have these in Scandinavia, or at all in Europe under their own brand, only heard of Hyundai here.

We're still thinking of a budget Chinese TPH backhoe, but with a separate hydraulic pump/gearbox attached to the PTO. Of course, we do have some load concerns of the tractor, but considering there is already a subframe in place for the FEL, probably the most important part to stabilize is the TPH toplink. We'll need both pieces, the tractor and the backhoe to further investigate how to progress on that matter.

We'll certainly avoid stump pulling in the beginning.


Edit: revised content

[traktorz]

Today we've been picking up our new LW-7 Tractor Backhoe. We were positively surprised to see the vast number of improvements that has been implemented in this new model.

Our biggest concern has been taken care of, by the supplied stabilizer (similar to other Korean and American brands).

Certainly, the evolution is an ongoing process, and this time it's definitively been going our way. We're actually quite happy to get all these product improvements, and to the same cost as the older models.

It also seems that the Chinese producers are genuine proud of their new products, see this picture of the foot rest & leg protector with their company brand name in relief.

Here below also the drawing of the backhoe, illustrating that now also a "thumb" or "grapple" is possible with this improved model. Additionally, as can be seen from the drawing, it's been revised this spring.

Of course, we need to put this new toy into a real test, but our expectations of this improved LW-7 backhoe really has risen into a substantially higher level. Stay tuned, and we'll soon let you know our experiences with this improved model.

[red]

Traktorz Congratulations on your new Backhoe!

Now check out that Hydraulic tank and tell us how clean it is? I filled mine with diesel and let it sit for a day or two. Then emptied it and used several rags attached to a stick to clean out the gunk (accessed though the filter screen opening) What a mess! The backhoe has work well for me and it was what I could afford. Also stole Larry G mod for the engine drain plug and installed a magnetic on the hydraulic drain plug. Good Luck! -Ed

[psj12]

Please be aware that many factories in China are making the LW-6-7 and -8 models. While they are supposed to be the same they are not always. I ordered a new bucket from a sponsor of this forum for a LW-7 and it would not fit my LW-7. I then had to go back to the original dealer and have him order a bucket to fit, from the factory that produced it.

I have modified my LW-7 to work off the tractor hydraulic quick disconnects and removed the tank and pump.

The swing control on mine is quite sensitive and jerky until you get the feel of it. Maybe they have improved the control valves since I bought mine.

[bradblazer]

Congratulations on the new machine!
For sure give us a review of the setup and initial operation. In the schematic it looks like there is an adjustable link that bolts to the drawbar mount. Is that the way yours came?

[traktorz]

Jun 16, 2010 20:49:27 GMT -5 red said:

Traktorz Congratulations on your new Backhoe!

Now check out that Hydraulic tank and tell us how clean it is? I filled mine with diesel and let it sit for a day or two. Then emptied it and used several rags attached to a stick to clean out the gunk (accessed though the filter screen opening) What a mess! The backhoe has work well for me and it was what I could afford. Also stole Larry G mod for the engine drain plug and installed a magnetic on the hydraulic drain plug. Good Luck! -Ed

As can be seen from the serial number, this brand new backhoe was manufactured only two months ago, on April 5th 2010. Since then it's been shipped to Sweden, which of course takes some weeks by boat. The revised design is dated less than a month earlier than the production date, on March 26 2010, according to the mechanical drawing.

There was a mirror of oil film ~100 mil of pure and clean hydraulic oil at the bottom of the tank, probably remnance from the delivery check at the factory. Discussed with a tractor mechanic expert and we agreed after inspection that the tank was perfectly clean for filling up with fresh hydraulic oil. I'm using Agrol Turbo Kombi SAE10W-30, a STOU oil in the entire tractor and backhoe.

[traktorz]

Jun 17, 2010 7:30:20 GMT -5 psj12 said:

Please be aware that many factories in China are making the LW-6-7 and -8 models. While they are supposed to be the same they are not always. I ordered a new bucket from a sponsor of this forum for a LW-7 and it would not fit my LW-7. I then had to go back to the original dealer and have him order a bucket to fit, from the factory that produced it.

I have modified my LW-7 to work off the tractor hydraulic quick disconnects and removed the tank and pump.

The swing control on mine is quite sensitive and jerky until you get the feel of it. Maybe they have improved the control valves since I bought mine.

Yes, it's confusing that so many vendors use the same product name LW-x [x=6,7,8,9], but with different generations. I'm happy that we got a freshly evolved model, with so many enhancements, especially the stabilizer frame. I'm going to measure the dipper and dogbone, in order to document it's measurements if we plan to order another bucket. There are several Swedish companies, that can tailor make buckets for your needs.

Our 48 liter bucket gap distance for the dipper is 110mm and the bolt is ø35mm.

There are pros and cons with a self contained closed loop hydraulic system, however the mounting of the PTO gearbox and pump is a bit of a pain, and the gearbox needs either gear-oil or grease.

I was fearing a sensitive and jerky behaviour of the backhoe, but was positively surprised that it wasn't the case. I expect product evolution has improved the control valve behaviour too.

[traktorz]

Jun 17, 2010 8:40:53 GMT -5 bradblazer said:

Congratulations on the new machine!
For sure give us a review of the setup and initial operation. In the schematic it looks like there is an adjustable link that bolts to the drawbar mount. Is that the way yours came?

Thanks!
Regarding the adjustable link - that's new with this years model.
I'll update with pictures as soon as I picked out a representable selection.



I was expecting the mount work to be easy, however it was a bit more work involved, and without assistance it would have been rather difficult to unload and assemble the entire backhoe, especially with the stabilizer puzzle. Still it took me two afternoons to get it ready and operational. Two problems remains: I need a shorter toplink for the stabilizer subframe to the drawbar and also to figure out wheather I can mount the PTO gearbox upside-down (might swap the breather and the drain caps) in order to get some more space for the toplink.

The hardest work was to remove and mount all the pins within the bushings around the cylinder link bearings. I even had to put the pins into the deep freezer, to get some thermal help of putting them back in place. Sledgehammers and wood blocks were needed. We were surprised how tight the tolerances were. Maybe it's a good thing, since it'll take a longer time until they'll wear out.

Last, but not least, the backhoe works very well, the response from the valve kit is smooth and predictable, and even works well from idle speed of the tractor. We think it matches well to our tractor, and that it's a good investment based on our moderate budget.

Here's a picture of the teeth trio from the virgin dig today.

[traktorz]

I drove to the Swedish Jinma and Backhoe distributor, which happens to be located in the same County. They had packaged and secured the backhoe well, so it also should be quite easy to attach to the tractor later. The distributor had a fresh shipment of LW-6/7/8 models just arrived, some still in crates. Our backhoe has serial number #405, so quite a few has been sold in Sweden by this distributor.




The hydraulic pump CBN-E310 delivers 20 liter/min and is rated for 16MPa. It's attached to the PTO via a gerbox, that should use SAE90 gear oil, but the distributor actually recommends grease. It's bigger and bulkier than we like, which makes it impossible to mount/unmount without loosen the hose from the suction filter of the reservoar. I've only seen one breather plug on the gearbox, but no drain plug. If orienting the gearbox upside down was possible (and swapping the drain/breather plugs), the mounting/unmounting procedure would become much easier and interfere less with the hoses. There's a torque lock chain to prevent it from rotating. I filled the tank with a STOU oil, Agrol Turbo Kombi SAE10W-30, which we already use for the entire tractor (motor, transmission & hydraulics) and estimate that less than 15 liter was needed to reach the max level on the dipstick.




Loading the backhoe onto the trailer using a Volvo BM L-120 (16 ton), might be a bit of an overkill, but is the standard procedure and works well for the distributor. We also loaded a grader blade with hydraulic angle tilt adjustment, for road repair work and snow moving. It's a lightweight blade, but as wide as 250cm.






The 48 liter bucket measures 40 cm, and has three teeth locked with three bolts & dome nuts. I could see a need for a narrower bucket ~30cm for drainage digging, but rather a grading bucket without teeth for planning work. Maybe a wide piece of a boron-hardened steel grader blade attached to the triple holes on the existing bucket will do that job, however than we rather had a tilt function of the grader bucket as well.



Some spare parts are supplied like Tredo-rings and O-rings.


The bucket connects to the dipper with a bolt and a dogbone. The tight tolerances fit of the two bolts required some work with the sledgehammer and wood blocks to mount. We were impressed with the manufacturing precision and we expect it to take a long time to see the wear. We are using a more expensive Lithium-based NLGI 1.5 long-lasting grease on the backhoe, rather than the Calium-based NLGI 2.0 we are using on the tractor.




This years model of the backhoe comes with a stabilizer mount which is new for the LW-6/7/8, at least from this specific vendor. I've seen similar mount arrangement from other vendors, so it's a proven method. It connects the backhoe mainframe to the toplink mount, to the seat, and to the drawbar mount via a supplied adapter. With the parameters choosen, I cannot use the Foton tractor supplied toplink, since it's too long. It can be retracted to 46cm, but it needs to be max 41cm. I've found one supplier of a Cat. 1 toplink that adjusts between 407-595mm, so that will complete the mount.




This years model has a redesigned hydraulic reservoar, which now is oriented vertically in order to reduce cavitation and sucking air when digging in slopes with steep angles. Since it's a closed hydraulic system, there's no need for a tank return filter. I might plan to add one later, such as the Baldwin BT366-10 or LHA SPE16-10, both with a pressure relief valve built into the filter holder.




The hoses are now hidden and protected within the boom and the stick, remembering the old model had the hydraulic pipes for the bucket on the sides of the boom.

The operator area has been revised for better safety and is now containing both a large foot rest area and the leg protection sheet in front of the operator. That in adition to the stabilizer frame, makes our first impression that this version is safer both for the operator and the wear of the tractor.

There has been added large rubber absorber pucks to milden the side swing contact from the boom to the mainframe.

There's no more the two transport lock chains on the boom, rather it's now equipped with a bolt to prevent the side swing and also a bolt for the boom movement.

The backhoe is standing on two solid feet. I'm curious how these will work, when start digging on soft soil. Our tractor has also a front loader with a heavy bucket mounted, but I don't have any experience yet on it's optimum use for stabilizing the entire veichle when digging.


Valve unit control schematic



Overview image of our Foton FT404 tractor with the new LW-7U11 backhoe mounted and ready to use.

[Rich Waugh]

Looks like there's been some very good evolution gong o in the Chinese backhoes - that's great. Thanks for the excellent pictures and write-up.

Rich

[roy697]

Yes very well done. Congratulations.

[traktorz]

I've bought a hook for welding to the bucket. It's the smallest available and still rated for two ton. The question is where to weld it. To the left it will interfere with the removeal of the bolts. To the right will work better, but I still need space for driving the attaching bolt outwards. For symmetrical reasons, maybe the centre position is the best?

I want to hear your comments and to know where have you attached the hooks on your buckets?



Ref:

• Grävmaskinkrok svetsbar - www.swedol.se

[3RRL]

traktorz,
Below are a couple of photos of how I welded my grab hooks to the backhoe buckets.
On one bucket, I put 2 (one on each side). On the other bucket, I put 4 hooks. They are back to back so no matter which way I want to lift, one set will work for sure. I use 5/16" grab hooks which are the weld-on style. They are3 grab hooks and not slip hooks. I find the grab hook easy to work with rather than the slip hook. They work for either 5/16" or 3/8" chain. I have a Nardi 220, it's an Italian 8 foot backhoe, so a 5/16" chain is plenty for it.
Rob-

[traktorz]

Thanks for sharing your modifications with illustrative photos. Unfortunately, I haven't been able to source these kind of grab hooks in Sweden. Of course, I could order some from a USA supplier, however I now have the weld-on type that is available here.

Certainly these hooks makes both your FEL and BH more useful, so it's a good add-on.
Bigger excavators have them as well, normally integrated into the universal mount.

Like always, this site brings a wealth of good ideas, and four hooks on a larger bucket seems handy, like even for just moving and storing the unmounted bucket.

Given the hook I already have, how about another suggestion for the mount location?
This new idea is to move the hook to the bucket link. However, the bucket needs to be fully curled, in order to use the hook. At the same time it's more out of the way during the digging work. Additionally, if I want to mount another smaller bucket, I can reuse the hook, since it's not on the bucket itself.

Here below some photos to illustrate this new idea.

[3RRL]

I'm glad the photos helped.
I like the idea of attaching your hook where where your latest place is. Indeed it would be there for any bucket changes. I presume with the bucket fully curled, you would drape the chain over the bottom of the bucket or over the sides of curled bucket, right? So that would work fine without hurting the boom. If you drape the chain over the end, over the bottom of the bucket, be sure it does not slip off the bucket.

One advantage of having the hooks on the bucket itself, is that you can then use either the dump or curl to start moving the chain, or to tension it before lifting. I think I might have a few extra "weld-on" grab hooks like are on my equipment. If you want, I can send you a couple of them at no charge. All I ask is that you pay for shipping. If interested, send me an email or PM and give me your address. I will then look for the hooks in the barn and mail them to you.
Rob-