3-Point Hitch Motor Stalls when Arms at full height

[greg_g]

Oh..mine is a bit older, and has two levers. Is your version supposed to have both position control and draft control?

The Jinma 300 series does have draft control, but it's a pretty rudimentary system. Your second lever adds hydraulic sensitivity control to mechanical feedback, whereas the Jinma pretty much relies on mechanical feedback alone. The sensitivity relies on which hole set the toplink is pinned to. The single Jinma lever usually sits in the middle, which is also the draft control off position. Lifting the lever raises the three point hitch, lowering back to the middle drops it. Pushing the lever down turns on draft control. Draf

//greg//

 

[Rich Waugh]

Yes, my single-lever system has both position and draft control. As noted by Greg, the draft control is fairly rudimentary, but every draft control I've ever seen was also pretty rudimentary. When the control lever is below the midpoint of its travel, the draft control is activated and responds to pressure from a ground-engaging implement. When pressure is applied to the implement, the resulting drag causes a pull on the sensor valving which then opens the hydraulic circuit to lift the TPH arms. When the drag is reduced, the valve closes and the arms no longer lift and the implement returns to the depth it was set for. The "sensitivity" can be adjusted somewhat by which set of holes the linkage is pinned into. One set gives more leverage against the valve than the other does. Other than responding to drag and automatically compensating for it, the draft control section of the system function just like the position control section.

In the upper half of the control's travel, it is in basic position control, and that is where mine performs at its worst, in my opinion. I would like there to be a 1:1 relationship between the control position and the lift arm position, but it is far more arbitrary than that. I may need to go onto it and clean it all out and replace all the seals or something - I frankly know so little about it ( other than the basic theory) that I'm leery of tearing into it. I just wish it was more precise. The draft control, on the other hand, seemed to function fairly well the one or two times I tried it out - I don't do any plowing, so I have no real need for draft control.

I should probably try using the draft control section the next time I'm running the bush hog. It may very well have sufficiently better accuracy of position than the position control section to suit me fine. The 'hog won't have enough drag to engage the draft control, I don't think. If I actually remember to try this sometime, I'll post the results.

 

[greg_g]

I should probably try using the draft control section the next time I'm running the bush hog.

Don't bother, it's not heavy enough to exert the necessary pull on the toplink bracket. Draft control is almost exclusively used for ground engaging implements; plows, box blades, heavy duty rakes, et cetera. The deeper they dig, the more force is exerted on the bracket. At some point, the hydraulics lift the implement back to working depth. With the single lever type, that's hit and miss; controlled by which set of holes you use for the toplink. And every time you lift the implement, you gamble that the next time you drop it into draft control it will work to the same depth. With the two lever type, that depth is preset with the 2nd lever. Lift with the first lever, drop, and it will resume working to the depth set with the 2nd.

//greg//

 

[EE_Bota]

Fellows, although I don't have your system, I am interested in finding information and helping sort it were I able to help. I am willing to try.

My hoe is on, so I don't know that yours doesn't already perform better than mine. But:

unless they have enhanced it in some highly intelligent way, they made your lever control job and their position control linkage job twice as hard for them and / or you to accomplish. For that (guessed at) reason, I think adjustment would be more critical than ever for yours.

What can we make of it seems to be the main thing with these tractors. I, like you guys, would like to know as much as possible going in. Sometimes I go into machines with only the suspicion I can get out again without harming the machine. My lift box had the bold on top, so the pain/risk is lower than the ones where the box has to be removed.

I did a test for this thread..a simple one. Can I lift my lift arms higher than they go by use of the control lever. Some tractors like a bit of free play at the top to make sure the hydraulics never have to work against the housing in order to try to center the spool.

On my BX kubota, the setup is that you can STILL lift them a bit higher by hand, but it does not have position or draft control.

On the Farmpro, I could jiggle them..making me think that I am getting shaft play, not true room to move more. Yet, mine is not going into relief. To the OP, I did the test to see if maybe your lift is up against an internal physical stop, and cannot center the spool to stop trying to rise further. I think that is your problem..the thing is trying to rise because the linkage is not adjusted right internally or externally, and the interplay does not cancel the request by centering the spool.

I think it matters little whether it is adjusted inside or out, so long as the spool gets centered at the top. A bugger is...some say there is no relief in the lift box, and others say there is. I have read some documentation that claims there is a relief. If there truly is a relief there, yours is adjusted wrong for sure.

So how or another...we need to nail down the facts about reliefs etc.

 

[Minial]

I think i may have found the issue with the arms ..have found the small feedback shaft at the distributor unit was seized so there was no movement in the feedback linkage from the 3 point linkage arms when they reached the full height .Have yet to install the unit back on the tractor so until then won't really know but it has certainly made a difference to the main control valve movement in the distributor unit .. watch this space!!:laughing:

 

[Minial]

I'm a happy chappie ..it works !!
Had to adjust the link arm and it all works as it should .:thumbsup:

 

[EE_Bota]

I'm a happy chappie ..it works !!
Had to adjust the link arm and it all works as it should .:thumbsup:

Excellent! I am happy for you.

Any pics?

 

[Minial]

Hopefully i have managed to attach a couple of pics to show the adjustable linkage and the small arm that was seized(Right side of pic))

 

[EE_Bota]

Hopefully i have managed to attach a couple of pics to show the adjustable linkage and the small arm that was seized(Right side of pic))
View attachment 269869View attachment 269870

Thank-you very much. I had no idea that the valve is external on your tractor. Excellent job sorting it and getting it up and running right.

 

[rhogg4594]

If i take the arm lift lever to high the engine will stall..at the moment i have to stop maybe an inch or more before the top of the quadrant to stop it stalling..anyone out there with ideas as to what is causing this to happen?

I have a Mahindra 254 and when the control lever is raised to the absolute top it is meant to operate the pump continuously to the rear hydraulics for raising a tipping trailer for example. If there is nothing attached then the engine struggles because it is pumping to a blocked end. So when raising the 3ph you are meant to stop before the lever reaches the top. And on mine there is an adjustable washer to limit the amount of travel of the lever. I was wondering whether you might have the same system hence the engine struggling or stalling.

On another note my control valve system no longer pumps to the rear, anybody know much about these control units?