Catastrophic hydraulic top link failure

[MtnViewRanch]

When metal is (snapped) as it was in this failure, that is what it looks like. I have seen smaller sized I beams of steel and aluminum that have had this type of catastrophic failure and the broken edges looked very similar. I have personally broken a 1 1/8" dia hydraulic rod and it too looked the same.

 

[Scooby074]

Brian,
Are the components in your TnT, like the rods and tubes American sourced? Or are they imported?

 

[nomad]

Of course, this failure, snap, is a result of sudden, impact force on the eye. But, this is a part with the hydraulic which should have absorbed/dumped at least a certain amount of shocking forces. You can say response time to shock force was so short that there wasn't enough time for response of hydraulic. Although this is a probability and a possibility, I still think there was a factory default in that eye, probably, a very small crack (say, of a millimeter size) inside or at the edge of the eye. That very small crack responded shocking load earlier and propagated fast like in a glass. Seller must do some tests by chosing some links randomly. If most of them fail, then, it is a forge (die or material or even heat treatment) error. If 1 of 20 links show similar fail, then, the seller should ask manufacturer to make a better quality control before the product goes out of factory door.

 

[MtnViewRanch]

Brian,
Are the components in your TnT, like the rods and tubes American sourced? Or are they imported?

They are imported. If I were to use all made in the USA stuff, I WOULD BE OUT OF BUSINESS. Sad but true. I believe that the end that failed is made here, but I would have to double check that to be 100% sure. I personally build most of the clevises for the side links and they are built with steel made in the USA. :thumbsup: But to use actual USA sources for the cylinders themselves, just about double the cost and no one and I mean NO ONE wants to pay that price. Talk is cheap, but when it comes down to it, no one is willing to put out that kind of money. That has been my experience anyway.

 

[nomad]

Indeed, talk is cheap. There is no manufacturing works in Western world anymore. Not only Western world, in big part of the world. In last 2-3 decades, China have dominated whole world manufacturing industry, sometimes visibly, sometimes invisibly (by putting other labels, labels of buyers, orderers, etc.)

People still live out of time, as if the date is 1960s, 70s when there was heavy industry manufacturing everywhere. But, then, even Soviet republic products were much more stronger than Western products too. For example, in this small town industry, we still have 40 years old turning lathes made in former Czechoslovakia and they were built stronger than other lathes in the world. Now, do you see any lathe production in new Cezch or Bulgar republic etc? No. Time has changed. Now, we can say almost everythings, good, bad, etc in the world are coming from China, partially or completely, directly or indirectly. Some smaller manufacturers in the world out of China who are trying to compete China mfgs are lowering qualities too to lower the prices to compete them. So, today, not all bad quality products are coming from China.

 

[SPYDERLK]

Here's a closeup of the metal surfaces that broke.

I too am very glad it didn't happen with the 2200 lbs chipper attached! My stump grinder weigh a little over 1000 lbs. My Bush Hog 3209 cutter weigh as much as the chipper, maybe even a little more. I also recently got a Valby 3pt log grapple that could have put a lot of stress on the top link when lifting logs off the ground.

The top link is a 3" cylinder and cat2 specs as far as the pin dimensions, etc.

I did contact the seller and a replacement is on its way at no charge. It also incorporates a different design with beefier ends.

srs, yes, I certainly have been though a lot worse than this before!

To understand real technical reason, the crack should be studied in a laboratory. It can be due to fatique or manufacturing error (weak structure, forge default, material, heat treatment, a residual crack at beginning propagated later in time which showed itself at a shock load.) We don't know real reason for failure, but, we know one thing that it isn't the cylinder which failed first, so, even if it was a manufacturing error, it must be an accidental, escaped out of quality control type of product. Poor quality toplinks usually fail in cylinders, causes leakages, etc. Eye in this toplink is a cheap part of the total cost, so, I don't think mfg error is intentional if it is mfg error.

The quality of this picture shows that the failure was very sudden. It may have been instant, or may have begun as a crack a million or so milliseconds before that stayed tiny until the high failure load. The failed area is fresh and shows no rubbed area or rust. With some attention in the finishing stages that meager eye could probably reach an acceptable durabilty level by blunting/peening all sharp edges/corners in stressed areas. Thats the kind of thing to do only if you are stuck with it. ... More metal is cheap in this application. MtnViews fix will be bullet proof.
larry

Yes, Brian has been great to work with. I had a response within hours of sending him a pm, stating he would get started immediately on a new link with heavy duty eyes, and cover shipping, including return shipping on the failed unit. Truly a stand up guy and a pleasure to do business with! I wish more companies that I deal with were like that!

Several of you asked what the eye on the other end looks like. Here's a shot of it. I examined it closely and I can't detect any signs of stress, so I think it was just a fluke that the other end let go.

I wouldn't say that I have been abusing my top link from Brian, but I certainly haven't been gentle on it either, especially with my 2000lbs+ implements going over rough roads, fields and stumps on the woods.

Yipes! Those eyes appear to have much less side swivel than is conventional. Might be hitting the limit if the implement swings a bit. If so its not a good thing.
larry

Of course, this failure, snap, is a result of sudden, impact force on the eye. But, this is a part with the hydraulic which should have absorbed/dumped at least a certain amount of shocking forces. You can say response time to shock force was so short that there wasn't enough time for response of hydraulic. Although this is a probability and a possibility, I still think there was a factory default in that eye, probably, a very small crack (say, of a millimeter size) inside or at the edge of the eye. That very small crack responded shocking load earlier and propagated fast like in a glass. Seller must do some tests by chosing some links randomly. If most of them fail, then, it is a forge (die or material or even heat treatment) error. If 1 of 20 links show similar fail, then, the seller should ask manufacturer to make a better quality control before the product goes out of factory door.

They are imported. If I were to use all made in the USA stuff, I WOULD BE OUT OF BUSINESS. Sad but true. I believe that the end that failed is made here, but I would have to double check that to be 100% sure. I personally build most of the clevises for the side links and they are built with steel made in the USA. :thumbsup: But to use actual USA sources for the cylinders themselves, just about double the cost and no one and I mean NO ONE wants to pay that price. Talk is cheap, but when it comes down to it, no one is willing to put out that kind of money. That has been my experience anyway.

There are always flaws where a crack can start. 1st, sharp edges are flaws - then grain boundaries. Whether or not force is applied rapidly or gradually, all things will fail given enuf force - even perfect metallurgy and optimum design. ... That is, if sufficient amt of material is not employed in that design. In this case it just needs more material to give it a better performance margin; one that is tolerant of imperfection. It looks as tho the same eye is employed for both Cat1 and Cat2. The cat2 config is pushing it too far. Not only is there less material available around the larger ball, the amt of swivel is limited to the point that it may bind and cause bending loads, damaging itself during use. [There is some evidence of this in the 2nd pic.]
... The larger eye being adopted is a perfect solution for this situation. They will be totally durable.
larry

 

[Kioti Tom]

No doubt about it. I have been looking at hyd. toplink prices. The choice is made.
Brian is getting my order when I order in feb. Good selection and stands behind his products.
Have to recover from getting a new ETA boxblade and Christmas first. :laughing:

Tom

 

[Scooby074]

Brian, thanks for a straight up, honest answer.

I myself go out of my way to buy Canadian and American made, but I know what you mean about consumers in general.

 

[MtnViewRanch]

What I have available to me at the present time at a reasonable price is the following.

Cat 1 with a 2 1/4" dia housing that is 1/2" wide. these are what get used on my 2" dia cylinders.

Cat 2 std duty. 2 3/8" dia housing that is 11/16" wide. These are what get used with the 2 1/2" dia cylinders. If a 2 1/2'"cylinder needs to be cat 1, (over 1/2 of them) then I use the cat 2 end and bush it down to cat 1 and grind the 2" width down.

Cat 2 heavy duty. 2 7/8" dia housing that is 11/16" wide. These are what get used on the 3" dia cylinders.

If anyone can point me in a direction to where I can get better ends at a reasonable cost, PLEASE do so. I can get waaaaaaaay better ends no problem, the problem is that NO ONE is willing to pay for them. You guys need to realize that there is a price point that has to be met, or you don't sell anything.

 

[Baby Grand]

Yipes! Those eyes appear to have much less side swivel than is conventional. Might be hitting the limit if the implement swings a bit. If so its not a good thing.
larry

I hadn't noticed that, but you're right. Good eyes, Larry. Bottoming the swivel out will create a huge prying load on that little ring of material.
Big moment + little wheelbase = Doh!