3320 rockshaft doesn't rock

[kennyd]

I got a new 3320 with the 485 hoe delivered a week ago saturday and had the same problem. The dealer came out and tried to get the 3 point hitch to work with no luck. They
came back the next day and took it back to the shop. They got the hoe off and said that
a hose was hooked up wrong from the factory? They put the hoe back on and brought it
back to me last Friday. I was able to take the hoe off with a little help from the stabilizers.
The 3 point hitch seems fine now.

Be nice to have clarification of "which" hose and "where" it was hooked up "wrong"?

 

[JD4ME2]

I'm not sure what was plugged in wrong, but I have everything tagged now. They think it got over pressured and caused the stabilizer cylinder to start leaking. They rebuilt the cylinder and everything seems fine now, except the 3 point hitch can't quite pick the hoe up high enough to take the L pins out, but you can feel it trying, which is more than it did before. I won't be putting the hoe back on for at least a week with all this rain.

 

[CinderSchnauzer]

There was a previous post on this subject which seemed to suggest there is an adjustment for the rockshaft lift height. When I had this problem, the tech told me there is no adjustment, however, he enlarged the holes that postion the two adjustable lugs that the rockshaft pins lift against and was able to get enough movement so that the rockshaft actually lifted the BH high enough to remove the L Pins.

In either case, tell the dealer to watch the JD video - how easy the BH is to install / remove and tell him when yours works the same way you will be happy. Supposedy that's one of the selling features, so fooling around with the stabilizers to get the BH on / off is not the way it's supposed to work.

 

[sdicesare]

The arms do not have to drop to the bottom to lift, but you may very well have air in the system and perhaps manually pushing the arms all the way down (turn the drop rate valve all the way to the rabbit, counter clockwise I think and they may drop on their own) and then raise them with the control and drop them again, several times and who knows, it may work.

Ok, believe it or not, just cycling the rockshaft manually solved this problem. After I removed the hoe completely, using the stabilizers, and got it away from the rockshaft pins far enough so that I could push the rockshaft arms all the way to the down position, I heard a "squishing" sound. It sounded like hyd fluid moving air. Afte I did that, the rockshaft now works perfectly. The question I have now is : Why does this happen? Is it a function of just being a new tractor, and it won't happen again, or does an air lock occur upon sitting when you don't use the 3 pt for a while, which was the case here. In any case, thanks for all of the helpful insight.

 

[Cocre]

Well, that's good. I can't imagine the tractor coming from Deere with air in the rockshaft system, perhaps when the Power Beyond lines were run air was introduced. Even then I would think the lift would have been used to mount the backhoe, but perhaps not.

I take the hoe on and off my 3320 often and have never noticed air in the system, but over time the hydraulic oil may leak down and allow air to enter.

 

[beesberry]

In the manual pg 19-20 there are instructions on adjusting the position of the movable latch pins. Also in manual --- see your JD dealer for rockshaft position adjustments. Mine was never adjusted correctly from day one. I just use the out riggers to lift the hoe and put the pins in. If adjusted wrong you can damage the hydraulics.

 

[phj]

OK, believe it or not, just cycling the rock shaft manually solved this problem. After I removed the hoe completely, using the stabilizers, and got it away from the rock shaft pins far enough so that I could push the rock shaft arms all the way to the down position, I heard a "squishing" sound. It sounded like hyd fluid moving air. After I did that, the rock shaft now works perfectly. The question I have now is : Why does this happen? Is it a function of just being a new tractor, and it won't happen again, or does an air lock occur upon sitting when you don't use the 3 pt for a while, which was the case here. In any case, thanks for all of the helpful insight.

I too have had this same problem ( on a 4520 ) and it has grown to the point that I sometimes lose either the power steering or the 3pt lift or both. I believe it has air in the system but the dealer has said no. It is going back for the third time next week and will not come home until it's fixed.

 

[sdicesare]

Your hydraulics are connected correctly. Can you raise the lift arms manually? Is the hoe still on the tractor? If the hoe is still on, the arms cannot drop much because they are hung in the hoe hooks, and may not lift sufficiently to remove the hoe if not adjusted correctly (see below). Did the hoe work correctly when attached?

There is a rockshaft height adjustment mechanism on the left lift arm. Make certain it has not come loose or something. Its adjustment determines the max lift of the hitch arms. The "feedback rod" is lengthened to increase lift. Do not adjust it (too long) to where the system goes into relief. Should be 17.7 inches from center of lift arm pin to top of PTO cover.

With only 20 hrs on the machine I wouldn't monkey with it too much, just call the dealer.

I now have come to the conclusion that as others have reported, that the rockshaft arms will not lift the hoe far enough to install the L-pins, requiring the use of the hoe hydraulics to put it in position. I agree with others that this is a pain. It's supposedly designed to work as advertised. I am waiting to receive a technical manual which will hopefully address this, but how does the rockshaft height adjustment mechanism on the left lift arm work? If I could get it to lift just another inch or so, I could probably get the pins installed. Thanks.

 

[Cocre]

I now have come to the conclusion that as others have reported, that the rockshaft arms will not lift the hoe far enough to install the L-pins, requiring the use of the hoe hydraulics to put it in position. I agree with others that this is a pain. It's supposedly designed to work as advertised. I am waiting to receive a technical manual which will hopefully address this, but how does the rockshaft height adjustment mechanism on the left lift arm work? If I could get it to lift just another inch or so, I could probably get the pins installed. Thanks.

On the left lift arm axis there is a piece of tube with a threaded shaft running through it. The shaft sandwiches the tube between two nuts. If you loosen (CCW) the nut (15mm wrench I think) nearest the rear of the tractor a couple of flats and then turn the front most nut CCW to take up the slack you created by loosening the rear nut, you have effectively lengthened the shaft (rod) and will cause the hitch to lift higher.

I would only do a couple of flats at a time and then test the results. Do not adjust to the point that the lift goes into relief. It is a combination of lift adjustment, hook adjustment, and patience. Tighten things up when you are done. If push comes to shove, rather than grind the hook slots I would recommend getting a couple of bushings from TSC or elsewhere. I can't remember the exact size, 3/4 to 1 inch maybe. Slip them over the lift pins and you get another 1/8 lift for next to nothing.

At any rate, even using the stabilizers, the hoe goes on and off fast with practice. The best advice I have is to but a cinder block or chunk of wood under the bucket when you drop the hoe. If you do not do that the hoe will lean back too far and you will not get the lift pins to engage the hooks.

 

[sdicesare]

Thank you. I now have practice using the hoe stabilizers to attach and remove the hoe. I am not pleased with JD's advertised performance on this. I am pursuing other avenues to obtain satisfaction but in any case, I also have developed a system from which others might benefit. I made a platform from two laminated 3/4" ply sheets with 8 - 1000 lb casters onto which I can lower the hoe. I can then move it into position more easily, and still use the stabilizers to lift the hoe to get the pins inserted. Hope this helps.