JD 3320 Rockshaft control valve issue

[case580]

I have read through a lot of old postings about this issue but I can't find an answer for my situation.
My 3320 (1650hrs) has a noticeable extra load on the motor when the 3-point arms reach the full up position, I can move the lever down slightly and the excessive load goes away. I have attached 4 pics of the rockshaft control pilot valve. I have eliminated all the more common issues like manual adjustments to rockshaft valve or linkage rod, I have the correct hydro fluid, all filters are clear, etc. My 3-point arms only respond when the handle/lever is near the 5th height level basically about 3/4 the way to the full up position, if I push down on the lever slightly the arms will drop all the way down even though the lever is not all the way down. I followed the lever linkage down to the rockshaft control valve (see pics) played around with the linkage rod stop adjustment but that did not change anything. I pulled the cover off the valve, turned the engine over with the 3-point lever in the down position and noticed hydro fluid coming from the front of the valve (has some type of small machined rod piece in the hole), I then raised the 3-point lever to the up position, turned the motor over again and noticed hydro fluid coming through a hole on the side (next to the K in the pic) of the valve with much more pressure than the fluid coming from the front of the valve. I removed the valve and now I don't know what I should do. Pull the valve apart and look for debris, check for excessive wear, etc I'm lost. Ask questions or request additional information.
Thanks for reading my post!

 

[case580]

Fixed! Turned out to be an incredible easy fix. One of the first parts I checked when diagnosing my problem was the roll pin on the rockshaft stop, I took a look and confirmed the pin had not fallen out because I read that happened to others with my same problem. Like I said in my original post I went through many more steps looking for the problem with no luck. I found myself going back to one of my original parts to check (the roll pin) and said I'm going to knock out the pin and pull that part off to check the shaft that it attaches to. That is when I found what was my problem all along. See the picture and you will understand. Yes, that is the part I took off (lever piece that connects to the rockshaft stop adjustment linkage) and yes that is a piece of roll pin sticking out both sides giving me the impression that the pin had not fallen out but I never once thought that the pin could be broken off in the shaft and that was in fact what happened! One picture shows the part partially removed and a red arrow pointing to the broken part of the roll pin still in the stop shaft. Replace the roll pin then put everything back together and it works like a new one.
Thanks for all those that read my post. Now that I know a lot more about John Deere 3-point and rockshaft systems maybe I can be a resource for someone else.

 

[jenkinsph]

Glad you figured it out.:thumbsup:

 

[Blackstick]

Thank you so much! This was the solution to my same problem. I've been fighting for over a month now.

 

[dougsimp]

Was the lower shaft seized up on your tractor? Mine will not rotate and I think that is what caused the pin to snap.

Do you have any tips for removing that shaft? I have the control valve cover removed... I've tried a few things to get it out to no avail.

Thanks in advance for any info.

Doug

 

[mikeeg02]

For those of you who have been in this far, how do you get the limiter (highlighted in green) off? Is it just supposed to slide once the support collar is off?

Mine aint moving, and I am pretty sure the oring needs replaced where it goes through the housing. It leaks pretty badly. But I cannot seem to get the limiter off. I am assuming the woodruff key is rusted fast. Unless I am missing something else? Its just not going to budge it seems.

 

[mikeeg02]

For those that have to go this far, the limiter is supposed to just slide off. (theres plenty of never sieze in there now) Unfortunately for me, mine was siezed. After careful persuasion, the shaft actually snapped. When I went to remove the feedback arm to replace its o-ring (while I was down that far) it was also siezed, and I was able to just use an adjustable and twist the arm off. (From inside the housing) The oring on the rockshaft adjustment arm was completely gone, and where my leak was coming from. Funny thing is, the machine isnt rusted and is a 2012 according to the serial number. Just my luck I suppose!