FEL pistons housing hits FEL arm(s)

[DK35vince]

I agree with tommu56.
The only thing I see wrong is crappy bucket stops letting the bucket roll back to far causing the tilt cylinders to touch.
It needs better stops for when the cylinders are extended also to stop the QA from digging into the loader arms.
Weld in some better/stronger stops and you will be fine.

 

[gpflepsen]

I'm not understanding your train of thought. Backdragging in full dump position (the most vulnerable position for damage) is putting compressive forces on the curved linkage plates and the fully extended curl cylinders. When backdragging (tractor in reverse) the bucket wants to curl back to the neutral position (the curl cylinder rods withdrawn in the cylinders). I can see where this could create excessive compressive forces causing the curved linkage plates to wrinkle thus causing the secondary alignment issues.

If you look at the attached picture of the loader links, and imagine the bucket in use for back dragging, trace the forces as they would be transmitted through the links to the cylinder. The cylinder would be in compression. The short link between the bucket and rod would be in compression. The curved link would be in tension.

If you are front dragging or dozing with the cutting edge, the forces are reversed. The curved link would then be in compression and susceptible to buckling. This is the mode that the link is seeing failure.

Front dragging would be pulling on the curved linkages and wrinkling of the metal would be less likely but not out of the realm of possibility(IMO).

Either way, to my knowledge, front dragging or back dragging with the curl cylinders fully extended (with the bucket in full dump position) is not a recommended procedure.

I would agree.

I would be curious to see if changing out the wrinkled curved linkage plates line things back up. Has it been established that the curl cylinder rods are not bowed?

If the cylinder rod was bowed, pull the rod pin and rotate it 180 degrees. I don't think this would gain anything, but would only take a few minutes to do. Just beware if the zirc gets put in a bad position.

There is a duplicate post on this issue posted in the Kioti forum.
http://www.tractorbynet.com/forums/.../161951-front-end-loader-pistons-housing.html

Don

It was posted in the other thread that backdraggng in float will protect the loader from damage. I would disagree with this thought. Backdragging should be safe if the cutting edge is kept to an angle below some value, say somewhere less than 20-30 degrees.

I'd suggest replacing the links to return the clearance with the cylinder.

 

[Coyote machine]

http://www.tractorbynet.com/forums/...front-end-loader-pistons-housing-82231962.jpg
The image above from gpflepsen is the correct setup for my DK-35 and fel KL-351.

It is currently my opinion that the stops on the Q A plates bent due to hitting the stops on the underside of the fel arms. When this occurred, (and for sake of this discussions lets say it happened while backdragging the bucket in the maximum dump position) the Q A stop plates bent enough to allow further travel of the hydraulic pistons, which then caused bending of the 1/2 moon bars and additional damage was a result of the pistons hitting the fel arms and so on until where things are now. Fixing everything I just described will treat the symptoms and not the cause. Backdragging with the bucket in the full lock dump position is fine so long as nothing is encountered while doing so. For instance, lets say a rock pulls the bucket away from the fel stops (forward and away from the operator) and then the bucket edge 'hops' the rock, the bucket then slams the Q A stops into the fel stops and bends them. Once bent the pistons can travel further than they should and cause the additional damage to the 1/2 moon plates, fel arm ends etc. etc.

I want to see if I simulate the full dump position, (I can only approximate it since everything is out of whack), and release the pistons from their front pins CAN they travel further forward, ( dump) and if so by how much.
This may help to solve the issue and treat the problem. Of note is the idea that the tractor cannot sustain full dump position without damaging the loader while backdragging. I'm NOT convinced that the tractor, or any tractor must not be used in this way. It seems to fly against what the tractor is capable of doing albeit maybe to a lesser degree, or the design might need tweaking to allow it to backdrag without sustaining extensive damage.?
Thoughts, comments?

 

[gpflepsen]

I don't think those "stops" should or could be stops. The mechnical advantage of the cylinder would be too much for anything that close to the pivot. It just doesn't seem right. The stop should be the extent of the cylinder travel.

 

[DK35vince]

I don't think those "stops" should or could be stops. The mechnical advantage of the cylinder would be too much for anything that close to the pivot. It just doesn't seem right. The stop should be the extent of the cylinder travel.

They are stops. They are simply not made heavy enough. The QA needs to be stronger where it contacts the stops to keep it from wearing/bending.
The upper stop should stop the bucket roll back before the cylinders can contact the FEL arms.
The lower stops should also stop the bucket from dumping to far, before the cylinders can hit the end of there travel.

 

[Coyote machine]

They are stops. They are simply not made heavy enough. The QA needs to be stronger where it contacts the stops to keep it from wearing/bending.
The upper stop should stop the bucket roll back before the cylinders can contact the FEL arms.
The lower stops should also stop the bucket from dumping to far, before the cylinders can hit the end of there travel.

DK35vince,
I agree with you but I think there is some confusion as to when and where the stops are contacting the Q A assembly, etc. Let me clarify. When I push the bucket pistons out their normal full travel the stop that engages is the one where the Q A assy. hits the underside of the fel arms. These two stops restrict any further rollback of the bucket edge toward the underside of the tractor's nose.
What I don't yet know is: when the contact above is made and the tractor is used to backdrag the bucket edge while moving in reverse is it the weakness of the Q A stop hitting the underside of the fel's stop that causes the Q A stop to bend OR is it the cylinder trying to resist the forward force against the bucket blade, when something like a rock or other immovable object is encountered, that causes the bucket to go forward and then be forced back against the stop by the pistons pressure, with such force as to do damage to the Q A stops, as a result of the pistons being able to now overextend because of the bent Q A stop and so on until everything is bent beyond recognition?

Phew, hope that makes sense...it is a lot to detail, but I'm leaning toward the pistons being able to push harder than and further than they ought to if the entire fel worked as one would expect it to. For definition sake lets say the loader ought to be able to handle what the bucket can handle, and so far there is NO visible sign of distress to the bucket. I would therefore posit that the fel is the weak link as is exemplified by the damage incurred and the fact that it and not the bucket is taking the brunt of the stress. Furthermore the fel is under designed to handle the bucket it is intended to be able to support. From the opposite view if the pistons were designed to only travel so far as for the bucket to just touch the Q A stops on the underside of the fel then it would be impossible for the damage that has been sustained to date to have occurred in the first place. In fact, as the Q A stops became damaged the pistons would have likely restricted the further movement of the bucket, Q A stops bending further and any possibility of the pistons extending to the point that they would touch the fel arms. The other likelihood is the pistons would pull out of the cylinders or damage them severely, instead of what is happening currently.

So if I'm right, ( and I'm not saying I am, just supposing) then the solution would be to allow only so much extension of the pistons- LESS than the current design allows for. And to make the Q A stops more solid and less able to bend, thus eliminating the current mess known as my tractor.

 

[dcyrilc]

DK35vince,
I agree with you but I think there is some confusion as to when and where the stops are contacting the Q A assembly, etc. Let me clarify. When I push the bucket pistons out their normal full travel the stop that engages is the one where the Q A assy. hits the underside of the fel arms. These two stops restrict any further rollback of the bucket edge toward the underside of the tractor's nose.
What I don't yet know is: when the contact above is made and the tractor is used to backdrag the bucket edge while moving in reverse is it the weakness of the Q A stop hitting the underside of the fel's stop that causes the Q A stop to bend OR is it the cylinder trying to resist the forward force against the bucket blade, when something like a rock or other immovable object is encountered, that causes the bucket to go forward and then be forced back against the stop by the pistons pressure, with such force as to do damage to the Q A stops, as a result of the pistons being able to now overextend because of the bent Q A stop and so on until everything is bent beyond recognition?

Phew, hope that makes sense...it is a lot to detail, but I'm leaning toward the pistons being able to push harder than and further than they ought to if the entire fel worked as one would expect it to. For definition sake lets say the loader ought to be able to handle what the bucket can handle, and so far there is NO visible sign of distress to the bucket. I would therefore posit that the fel is the weak link as is exemplified by the damage incurred and the fact that it and not the bucket is taking the brunt of the stress. Furthermore the fel is under designed to handle the bucket it is intended to be able to support. From the opposite view if the pistons were designed to only travel so far as for the bucket to just touch the Q A stops on the underside of the fel then it would be impossible for the damage that has been sustained to date to have occurred in the first place. In fact, as the Q A stops became damaged the pistons would have likely restricted the further movement of the bucket, Q A stops bending further and any possibility of the pistons extending to the point that they would touch the fel arms. The other likelihood is the pistons would pull out of the cylinders or damage them severely, instead of what is happening currently.

So if I'm right, ( and I'm not saying I am, just supposing) then the solution would be to allow only so much extension of the pistons- LESS than the current design allows for. And to make the Q A stops more solid and less able to bend, thus eliminating the current mess known as my tractor.

I'm no expert here by any means, but from what I have been reading on various threads, it seams to be normal for the FEL pistons to travel further in both directions than full dump/curl of the bucket.

3rrl did a nice write up on his wifes Jinma which had a problem with the FEL also. http://www.tractorbynet.com/forums/chinese-tractors/124396-add-more-bucket-curl-jinma.html I'm pretty sure he had to rework the stops to prevent the ram contacting the FEL.

 

[DK35vince]

I'm no expert here by any means, but from what I have been reading on various threads, it seams to be normal for the FEL pistons to travel further in both directions than full dump/curl of the bucket.

Thats right. The stops should be set to keep the cylinders from bottoming out or touching the Fel arms when rolled back. They should also be set to stop the bucket when dumped slightly before the end of the cylinders travel to protect the cylinders from hitting the end of their travel.

 

[DK35vince]

What I don't yet know is: when the contact above is made and the tractor is used to backdrag the bucket edge while moving in reverse is it the weakness of the Q A stop hitting the underside of the fel's stop that causes the Q A stop to bend OR is it the cylinder trying to resist the forward force against the bucket blade, when something like a rock or other immovable object is encountered, that causes the bucket to go forward and then be forced back against the stop by the pistons pressure, with such force as to do damage to the Q A stops, as a result of the pistons being able to now overextend because of the bent Q A stop and so on until everything is bent beyond recognition?

It is because the stops on the QA are not strong enough. Weld some plating on the underside of your QA to stop the problem when in the dump position.
Also your stops in the roll back position also need to be improved to stop the bucket before your roll back cylinders can touch the Fel arms.

 

[Coyote machine]

So vince, based on what you said wouldn't the repair fall into warranty category? Since the Q A stops are weak/not strong enough to actually stop the rams from pushing them beyond their limits it would seem to me to be more of a design flaw than an operator error.

Cyril, thanks for the link on the Jinma, I've read it through in detail.