JD 3520 rockshaft operation.

[ldpfeifer]

I just bought a JD 3520 with a 447 backhoe. I have the manual for the backhoe and downloaded the manual for the tractor. I am trying to remove the hoe and cannot get the rockshaft to move down or at all. It is all the way back and moving it forward does nothing. I turned the DROP/LOCK valve all the way to fast and still no movement. I also have the bypass hose installed. Am I doing something wrong here as I cannot for the life of me figure out why it will not move. I tried to rock the tractor a little forward and backward ever so slightly to see if it was in a bind and still no movement. The hoe and bucket work fine. This is a used tractor with 541 hours on it. I read a little about bad rockshaft valves here but anyone have any ideas what I am doing wrong? Thanks if advance as maybe I am stupid. My old 40 never failed me but then it was not as fancy as this either.
Lyle

 

[Cam-Saskatoon Canada]

Okay, this might be a dumb question, but are you sure you took the two pins out first before lowering the 3ph? If you have, then when that happens to me, I wiggle the backhoe sideways has hard as I can by hand and it usually falls down all of a sudden and scares me!!!

 

[ldpfeifer]

The two pins big pins that hold the hoe below the 3 point attachment? Yea, I pulled those. It appears the 3 point pins are centered and ready to drop. The 3 point unit will not move no matter what I do. I must be missing something.

 

[beenthere]

This is a shot in the dark, but did someone disable the rockshaft hyd. lines for power beyond ??

 

[brown40]

I have a woods 7500 on my 3520, which uses the stablizers to raise the hoe onto position instead of the rockshaft arms and I'll describe mine looking from the back--when the backhoe is hooked up the top female port on the right feeds the hoe and the male fitting on the left side returns to hoe oil back to the reservoir. The flex-hose gets capped when the hoe is used, The male port immediately below the female on the right side is the loop that feeds the rockshaft function--it won't unless the flex-hose gets attached beneath it on the right side (that the regular operating set-up). It looks like the rockshaft assist on the 447 is the means to get the hoe oriented and released, so you need to hook it up to bear the unplumbed hoe while you release the fasteners. A quick search will get you some diagrams.

 

[ldpfeifer]

Well I thought about it and did something we use to do when we farmed with D-6 CATS. I pushed the pin down on the bypass hose and bleed out some air and fluid. Down it came. Looking at the spider nests and such under there, I am not sure the backhoe has ever been off or at least it hasn't in some time. Got it now. Thanks for the help.
Lyle

 

[beenthere]

:thumbsup: