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Lift Cylinder Broke on Disc

11K views 11 replies 9 participants last post by  goodproblems 
#1 · (Edited)
I was given a 16ft wide John Deere disc last week. It didn't have a lift cylinder or hoses, so I went and got a generic cylinder.
I drove it home and everything appeared to work normally.

I went to attach it yesterday and while operating the hydraulic lift to raise it for attachement, the cylinder ram arm snapped off and the bracket on the disc where the ram arm attached bent severely (it is 1/2" thick, so it took a lot to bend it).

I have yet to disassemble because I'm waiting for my friend to come by and lend a diagnostic eye.
I broke in the down position.

My leading theory is that the "rocker shaft" seized and when the ram tried to push the wheels down, the resistance bent the bracket and snapped the piston shaft. The disc sat in the weeds for 15 years and I did NOT grease it yet, so rust is probably thriving.

My neighbor (without seeing the failure) thought maybe the cylinder is too long for the disc?

It was a 3" diameter cylinder with a 10" stroke. With the cylinder retracted, it seemed to fit perfectly. Since the ram broke while retracted, I suspect that the "throw length" wasn't the cause.

Any ideas?
 

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#2 ·
It looks to me that the bar that bent, should have been in a vertical position so the cylinder is pushing at top of the wheel frame. The cylinder would be mounted to the edge of the bar, not the end. The way you have it connected, it had to break something. You will need a longer cylinder for it to lift the disc.
 
#3 · (Edited)
Sounds right




I would tend to agree with that. The strap needed to be at least a little above the line of the cylinder so it would go up. It appears the strap and cylinder were either in a straight line or actually formed a shallow v. If it was the latter, the cylinder couldn't push the strap down so it went sideways. If you hadn't retracted the cylinder quite all the way, the strap and cylinder would have formed more of an A shape in which case the cylinder would have been pushing the strap into the right place rather than sideways.

Treefarmer
 
#5 ·
Maybe the yoke on the cylinder is not deep enough? JD does do a few things to their equipment that do require specialized parts. It may require a deeper yoke on that end of the cylinder.
 
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#6 ·
I grew up using a disk just like that and the stroke on the standard cylinder was 8". 8" stroke was the standard on everything back then.
 
#7 · (Edited)
Re: Broken Cylinder (NEW PICTURE)

I just uploaded this additional photo, which better shows the linkage area on the disc.

I will have to go and look at it again once it gets light out.
When we first connected it, the disc lifted no problem. We lifted it up and down a few times without issue and then I drove it home, lowered it and parked it.

It does seem possible, however, that maybe one of the mounting points for the bracket broke or came undone, which then formed the angle that caused the ram to bend the bracket rather than lift it. Looking at the photo, it looks like only one bolt is holding the bracket in place and that seems to me like it wouldn't hold the bracket in a fixed position. I'll go outside and see if it looks like it came free from a secondary mounting position or something.

See attached.

Thanks
 

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#8 · (Edited)
Does this disk have anything used for transport to keep this disk from lowering while traveling down the road? On the JD disk we used for many years there was two metal braces we would flop over the rams and then sit the disk down onto them so the weight of disk was resting on the transport braces rather than relying on hydraulics to keep the disk from lowering and working up a portion of pavement if a hydraulic hose was to blow for example. If everything worked fine prior to pulling it home I am wondering if transport bracing has now gotten in the way of the wheels/axle/hydraulic ram? Although we never tried, I am sure the hydraulics on the 1066 we used to disk with could have caused plenty of things to bend, twist, and break on the disk if we didn't pull the transport locks off the rams once we got to the fields. Not saying this disk would have anything on the ram specifically, just somewhere on the disk in general that could be binding things up?
 
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#9 ·
Update (MORE PHOTOS)

I took a look at the disc just now and it looks like something is not connected properly.
The 1/2" thick bracket arm is only secured by a single bolt, which doesn't make any sense because it shouldn't pivot.
There is a second hole, but it is rusted and doesn't look like a bolt had gone through it any time recently.
AND, there is a bolt wedged/stuck in the other brackets.

Pictures are worth a thousand words.

(I'm not aware of any "driving" brackets for relieving pressure on the hydraulics, but that isn't to say that I just don't see/identify them.
 

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#10 ·
We had a disc very similar when I was a kid.

The eyebolt at that rear of the lift should connect to a strap iron from the rear of the disc that can be pinned for road transport/cylinder removal.

Machine Machine tool Metal



When the cylinder is installed and ram extended, the weight is transferred to the cylinder attachment. The pin that was holding the disk in transport, is moved to the hole in the cylinder attachment. With this bolt in place, the cylinder will not retract too far allowing it to push straight back into to the axle assembly which is why the ram broke, it had no where to go. You really are fortunate that it didn't break the axle and/or attachment brackets.

Vehicle


The hex bolt jammed in between the two pieces appears to change the distance the lift plate would hit to maybe gain additional clearance by rotating the axel forward further. (?) Obviously it should not be there.

Rust


I hope that helps
 
#12 ·
Sounds to me like 56Nine Has the solution

Based on your descriptions and drawings, I think you're 100% correct.
I went out and looked, and sure enough it looks like I should have locked a bar while driving it down the road, and then upon arrival to the field, I should have locked the bracket with the pin. Since I didn't lock the bracket, it rotated downward and the cylinder bent the bracket and snapped it's shaft.

Attached is a photo showing the locking assembly.

I'll bend the bracket back in to shape, replace the cylinder, chalk the whole mess up to a learning curve and move on.

Thanks for your help!






We had a disc very similar when I was a kid.

The eyebolt at that rear of the lift should connect to a strap iron from the rear of the disc that can be pinned for road transport/cylinder removal.

View attachment 346458


Based on your descriptions and drawings, I think you're 100% correct.
I went out and looked, and sure enough it looks like I should have locked a bar while driving it down the road, and then upon arrival to the field, I should have locked the bracket with the pin. Since I didn't lock the bracket, it rotated downward and the cylinder bent the bracket and snapped it's shaft.

Attached is a photo showing the locking assembly.

I'll bend the bracket back in to shape, replace the cylinder, chalk the whole mess up to a learning curve and move on.

Thanks for your help!






When the cylinder is installed and ram extended, the weight is transferred to the cylinder attachment. The pin that was holding the disk in transport, is moved to the hole in the cylinder attachment. With this bolt in place, the cylinder will not retract too far allowing it to push straight back into to the axle assembly which is why the ram broke, it had no where to go. You really are fortunate that it didn't break the axle and/or attachment brackets.

View attachment 346466

The hex bolt jammed in between the two pieces appears to change the distance the lift plate would hit to maybe gain additional clearance by rotating the axel forward further. (?) Obviously it should not be there.

View attachment 346474

I hope that helps
 

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#11 · (Edited)
It would appear as though the entire pipe supporting the hub assemblies for the transport wheels rotates to raise and lower the transport wheels. If that is the theory of operation I'd say that the plate that your cylinder yoke is pinned to needs to rotate up on the bolt that is still there and see if the second hole in it lines up with the hole in the double angles. My guess is that bolt or pin sheared off and your cylinder yoke is wedged in the plate and stoking it out bent the plate sideways snapping the rod end. In order for that (bent) plate to work there has to be another bolt or pin in that upper hole to enduce torque from the cylinder to the pipe to rotate the wheels down, picking the discs up... and viceaversa to lower.

Dig that sheared off bolt out of there, remove the bent plate and straighten with heat and a BFH, re install and see if it swings up to match up with the upper hole.

The only other think I can think of is maybe there wer a couple of short link bars between the hole in the double angle and the hole in the plate. Either way, to work the pushing force needs another fixed point to convert to torsion in order to rotate the pipe.

I see 56-9 beat me too it... I type too slow...
 
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