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Discussion Starter #1 (Edited)
2004 JD4110 hydraulic transmission w front loader and power beyond kit.
Was changing out the hydraulic hoses on the power beyond kit the other day and had some hydraulic fluid drain out.
A few days later the rockshaft / 3 point lift stopped working.
Could this be airbound? How do you bleed this component. My loader works fine and implements hooked up to power beyond work as well. Hydraulic fluid level is ok per dipstick and sight level in back by PTO...
The problem is limited to the rockshaft.
I have never had any problems with it before.
Any thoughts?
Mike
 

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Hopefully this will help - my 4200 is different but it functions similar. I suspect the power beyond loop is not fully connected. On my tractor, when the power beyond is connect to a rear implement like a backhoe, the rock shaft is "disabled" - no pressure to the valve. All oil flows through the back hoe and back to the tank.

Check the connection - it might not be fully seated.

Good luck!
 

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Discussion Starter #3
Hopefully this will help - my 4200 is different but it functions similar. I suspect the power beyond loop is not fully connected. On my tractor, when the power beyond is connect to a rear implement like a backhoe, the rock shaft is "disabled" - no pressure to the valve. All oil flows through the back hoe and back to the tank.

Check the connection - it might not be fully seated.

Good luck!
It seems to be fully seated. When I unplug the power beyond from returning to itself there is a noticeable drop in engine rpm which leads me to believe the hydraulic pump is being loaded up by the dead ended line at the unplugged power beyond. I have to turn off engine to plug it back in then restart and is back to normal rpm.
I feel like the rockshaft is first in the hydraulic loop?, then power beyond take off and finally loader control valves. Not sure if that matters.....
Thanks for the help,
Mike
 

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I feel like the rockshaft is first in the hydraulic loop?, then power beyond take off and finally loader control valves. Not sure if that matters.....
On most of these CUTs it is the reverse of that. Mid-SCV --> PB ---> Rockshaft.
 

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Any thoughts on how to bleed any potential air from rock shaft?
Sorry. I don't know enough about your machine to help you with that. I was under the impression that they are self bleeding but have no way to verify that info.
 

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Discussion Starter #7
Sorry. I don't know enough about your machine to help you with that. I was under the impression that they are self bleeding but have no way to verify that info.
There is a tube out the top of the rockshaft housing that goes to what appears to be an auto-bleeder........So it would seem this should take care of itself........
Maybe there is some sort of filter or screen that is clogged between the PB and rockshaft?
Very Frustrated.....
Thanks for the thoughts......
Mike
 

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If the PB connector is fully seated and the load on the engine increases when disconnected, its probably hooked up correctly. I would start w/ the basics:

It seems like fluid is flowing unrestricted. Otherwise the engine would bog down as previously described and eventually the pump would burn up.

Take a look at the diagrams on JD Parts. I'd begin with the mechanical linkage the moves the valves. It could be a loose component on the lever mechanism or the height control. The seat and/or some panels may have to be moved to access those parts. A while back, there was a thread about a 4300 that the rock shaft wasn't working - turned out to be a loose handle bolt.

When I bought my tractor, I splurged on the factory service manual. This has saved me a bunch of money. They are full of diagnostic procedures that seem to be well thought out. And, they have pictures and addition diagrams that may show other parts to check. It should also include the instructions for adjusting the maximum height.

Hope this helps.
 

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You have a blockage at the power beyond somewhere.

Before you do anything radical, MAKE SURE the power beyond jumper hose is quick connected properly. You must shut off the engine, and since you have had the engine running with the jumper hose not connected properly, with the engine stopped, jog the SCV several times, then connect the jumper hose quick connect.

Air is not the problem.
 

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Discussion Starter #10
You have a blockage at the power beyond somewhere.

Before you do anything radical, MAKE SURE the power beyond jumper hose is quick connected properly. You must shut off the engine, and since you have had the engine running with the jumper hose not connected properly, with the engine stopped, jog the SCV several times, then connect the jumper hose quick connect.

Air is not the problem.
10/8/18 - I tried cycling SCV hydraulics, plug / unplug PB, etc. no luck.... I do recall when noticing the problem the 3 point was raised, i lowered it part way and it would not raise back up, i lowered it further and again it would not raise back up, lowered it all the way down and it would not return either.....so there was hydraulic fluid present that held up unit and would drain out as lever was adjusted. Resupply of fluid does not happen.
Must be a blockage between PB and rockshaft supply?
I wonder can this be accessed by removing the rockshaft lowering control mechanism seems to be the only way into the rockshaft housing short of removing the entire assembly....
Thoughts?
Thanks for the help so far......
Mike
 

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Discussion Starter #11 (Edited)
Update 10/13/2018

10/8/18 - I tried cycling SCV hydraulics, plug / unplug PB, etc. no luck.... I do recall when noticing the problem the 3 point was raised, i lowered it part way and it would not raise back up, i lowered it further and again it would not raise back up, lowered it all the way down and it would not return either.....so there was hydraulic fluid present that held up unit and would drain out as lever was adjusted. Resupply of fluid does not happen.
Must be a blockage between PB and rockshaft supply?
I wonder can this be accessed by removing the rockshaft lowering control mechanism seems to be the only way into the rockshaft housing short of removing the entire assembly....
Thoughts?
Thanks for the help so far......
Mike
Update 10/13/18: Today i took apart the removed the PB 10mm plug to see if that changed anything, it did not.
I then removed the rockshaft lowering mechanism and found nothing out of place or clogged. I was able to pass a wire from the lowering area to the PB where the plug goes in to verify that was not clogged.
I cycled the motor briefly and witnessed hydraulic fluid coming out of the PB at the access point to insert the 10mm plug. So I feel safe saying that the issue is not in the loader controls, nor the PB as the backhoe and loader work fine when hooked up.
It appears to be limited to within the rockshaft itself I even cleaned the screen on the return hose where it leaves the rockshaft (25% covered with misc grit from years of use) fluid seems to be flowing ........
I'm baffled. The 3 point lift actuator shaft appears to be connected as it has never been touched by a wrench and is covered in factory paint.
I'll put a wrench on it and see what happens......
So I took the bolt off and the arm and the factory paint still hold the arm to the shaft and it operates without the locking bolt even in, therefore I would say that the shaft connection to the arm is not the issue either.
Fluid has to flow into the rockshaft housing to return to the pump from the SCV and PB so there must be a port maybe plugged inside the rockshaft?
QUESTION: Does open center system mean that the SCV PB and Rockshaft are getting fluid in parallel or series (an earlier post mentioned it was in series with the Rockshaft being last, but if the first two items work with no issue wouldn't the third not working clog the first two from working? unless the fluid return must be a common leg / parallel?
Anyone have a schematic of what a rockshaft internals looks like?
Thanks for any ideas you can provide...
Mike
 

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QUESTION: Does open center system mean that the SCV PB and Rockshaft are getting fluid in parallel or series (an earlier post mentioned it was in series with the Rockshaft being last, but if the first two items work with no issue wouldn't the third not working clog the first two from working? unless the fluid return must be a common leg / parallel?
Everything is in series for an OC system.
 

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Discussion Starter #14
Here's a link to the rock shaft valve parts diagram:

https://partscatalog.deere.com/jdrc/sidebyside/equipment/76924/referrer/navigation/pgId/17501482

Other diagrams are also here.
Thanks for link.
I have removed the rockshaft control mechanism and I have verified that the control arm is connected properly and cycle the interior components when hand lever is moved.
I'm thinking I must have a plugged supply port to the rockshaft control valve?
It seems the supply comes in to the control valve in between the two large o-rings with the return exiting the control valve closest to the top of the unit?
I wonder how to test this unit without disassembly as I can foresee springs and other stuff going flying all directions....
Any ideas?
Mike
 

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Discussion Starter #15
10/8/18 - I tried cycling SCV hydraulics, plug / unplug PB, etc. no luck.... I do recall when noticing the problem the 3 point was raised, i lowered it part way and it would not raise back up, i lowered it further and again it would not raise back up, lowered it all the way down and it would not return either.....so there was hydraulic fluid present that held up unit and would drain out as lever was adjusted. Resupply of fluid does not happen.
Must be a blockage between PB and rockshaft supply?
I wonder can this be accessed by removing the rockshaft lowering control mechanism seems to be the only way into the rockshaft housing short of removing the entire assembly....
Thoughts?
Thanks for the help so far......
Mike
10/23/2018
I removed the control valve, placed a piece of plexiglass over the opening and turned over the engine. I could see squirts of hydraulic fluid entering from the right hand side of the opening verifying no blockage to the control valve. Seems like it could be an issue inside control valve or between the valve and rockshaft....
Anyone have a procedure for taking apart control valve? seems risky to take this thing apart.......
Thanks,
Mike
 

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I had a problem with my 4400 that the feedback linkage from the 3pt froze in the housing and broke the role pin. Then the only option was either all the way up it all the way down.
I think it may be related to that some how. Their is no seal stopping water from getting between the shaft and housing. It will rust there and seize up.
The range shifter also froze up and I had to take it apart and clean and grease these shafts.

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Discussion Starter #17
Progress made - LOOSE ROCKSHAFT CONTROL LEVER BOLT!

So after diagnosing all other components in hydraulic system I discovered that the height adjust lever had indeed rotated on the shaft.
This shaft goes inside the rockshaft housing and operates a cam that pushes on the rear spring valve assembly that sticks out of the rear of the control valve assembly.
When this cam rotates a few degrees to far the cam actuator falls off of a roller on the linkage to actuate the control valve.
Realizing this I adjusted the cam into what I thought was the appropriate spot, reassembled everything and fired it up. The rockshaft came back to life however it topped out and with the cam adjusted to far forward it began to blow oil out of the control valve area of the cases.
I fear I may have over pressurized something in the control valve because I cannot get it to work again.
Does anyone have a factory procedure for adjusting this rockshaft control lever that includes how to position the cam?
I am trying to measure the depth of the control valve from the case mounting location then adjusting the depth of the cam actuator inside the case to the same depth and starting from there. seems like a good point to start however it seems like you cannot turn the cam back that far or it slides off the actuator and puts you back to square one. Frustrating....seems like a poor design.....any thoughts?
Thanks,
Mike
 

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Discussion Starter #18
Problem solved

What a weird design JD has to actuate the control valve at the rocker arm driven by a cam on to a roller mounted on a weird linkage.....seems like it could be much simpler.
However, It is quite amazing how much a small turn makes a difference to the shaft that the height adjustment lever attaches to. I guess if you look at it in degrees the throw on the height adjustment lever is merely 30-45 degrees of a total 360 degree revolution of this cam shaft inside the rockshaft housing. A small turn with a wrench changes many degrees quickly! This was my initial mistake in adjusting it.
I finally figured it out by measuring the depth of the control valve with the actuator at rest (fully extended) which was about 4.5 inches. When the actuator is compressed it is about 4.125 inches long. i then rotated the adjustment lever cam shaft to place the pushrod at the same max depth of 4.5 measured from the face of the rockshaft case at the control valve mounting location. This got me in the ballpark and I fine tuned the adjustment with everything reassembled and the machine running.
Lesson Learned: It is usually something quite simple that goes wrong!!!!
Thanks for the help.
Mike
 
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