3 point hitch: How to keep it raised?

[Tx Jim]

If it's the same as on my 3720, the feedback rod acts sorta like a psuedo draft control If the same across the model line, the feedback rod should be responsible for lifting the arms under load - not dropping them.
//greg//

Greg
I'm sorry but feedback rod isn't responsible for lifting the arms BUT the rockshaft control valve does that function. The feedback rod notifies the rockshaft control valve the location of the 3 pt so as if adjusted correctly puts RS control valve in neutral when set height of 3 pt is reached.

 

[greg_g]

Thanks. It's clear that the Deere engineers did some rethinking between the 4310 and my 3720. Appreciate the edification

//greg//

 

[bm3]

I have a Deere 3203 and have to tie the 3 PT control lever to the seatbelt bracket to keep it from falling. When its all the way up it will stay there but other than that it drops fast unless I hold the lever , it has nothing to do with the control knob under seat. 782 hours and this is my biggest problem so far.

 

[Tx Jim]

Thanks. It's clear that the Deere engineers did some rethinking between the 4310 and my 3720. Appreciate the edification

//greg//

Greg
Honestly I don't see that much difference in the RS control linkage on a 3720 & 4310. I still think the 3720 feedback rod and it's associated parts tells the rockshaft control valve when 3 pt has reached it's set height so as to put the RS control valve in neutral. I'm basing this info on my previous study of hyd systems while I served as a JD dealer service manager. I have made mistakes in the past and welcome anyone's input.
Jim

 

[RG1]

Tx Jim-

IMO/IME, you have it spot on in your assessment of how it all works together. I don't own the newer 3020 series, but I have looked at them and the 3 PH set up and function has been the same as the older 4X10series.

 

[Tx Jim]

I have a Deere 3203 and have to tie the 3 PT control lever to the seatbelt bracket to keep it from falling. When its all the way up it will stay there but other than that it drops fast unless I hold the lever , it has nothing to do with the control knob under seat. 782 hours and this is my biggest problem so far.

I don't have a tech manual for your tractor but there has to be a way to put more tension on friction washer(parts key #1) or spring washers(parts key #11) so as control lever(parts key #7) moves only by pressure from operators hand.

 

[RG1]

Here's a link to the 3 ph/rockshaft schematics on the 4310. Under pictorial index, scroll down to 70-1 then down to 10,12,13,14-

John Deere - Parts Catalog

 

[bm3]

Thanks Tx Jim , I will check it out again tomorrow , its been a real pain

 

[4310]

Well after playing around with it some more I am leaning towards the problem being the valve body seal. I've been playing in the snow some more and noticed the rear blade slowly dropping almost completely to the ground. I noticed that the 3PH lever did move down some (less than an inch) but the lever movement did not seem proportionate to the amount of drop that the rear blade moved. My gut feeling (and I have no idea what I am doing) is that pressure is being lost somewhere which allows the blade to drop down.

Now I just have to find out exactly what and where the valve body seal is and how to fix it.

 

[Tx Jim]

3 pt control handle should not move any amount after one removes their hand from lever.