3 point hitch: How to keep it raised?

[4310]

It's winter and I'm bored so I'm trying to think of questions to ask about tractors. Anyway I was out last night using the FEL on my 4310 to make a snow mountain for the kids to climb on and I had the rear blade on the 3PH. I wasn't using the blade and I noticed that it would occasionally drop down for no apparent reason. So I would pull up on the lever and get it back up off the ground and continue on.

Sooo I got to thinking that I really have no idea what makes the 3PH work and wondered if there was some sort of an adjustment on it. As it is now, and how it worked on my previous 850, if I pull the lever all the way up it goes into bypass (I think that's what it's called) and I can hear it hissing along with a loss of power. So I lower the lever just enough to stop the hiss and go on for a while until it drops down again.

It's really quite touchy too, which I was also wondering about. I can pull the lever up to the number 4 or so and the 3PH won't move, but I move it another hair and it raises up almost completely.

Anyway I was just wondering if that sounds about normal and also if there is an adjustment on it somewhere. I do know that the knob under the seat will keep it from bleeding down but I never seem to remember to use it.

Thanks

 

[Tx Jim]

The 3 pt control lever should have resistance to keep it where operator set it. Friction washer(parts key #14) and spring washers(parts key#10) perform this task on your 4310.
If you 850 went into relief when 3 pt was fully raised the linkage needed to be adjusted to eliminate this problem. Most tractors have a feedback rod that can be adjusted to eliminate going into relief at the top of lift

 

[greg_g]

Seems to me it should be a simple matter of adjusting the flow control valve. It's typically a knob beneath the front edge of the operator seat. It's purpose is to adjust the rate at which hydraulic fluid returns to the sump. If you have a heavy implement on the rear lift, you want a slower flow. That keeps the implement from dropping too fast and bouncing off the ground. If you have a light (or no) weight on, you want a faster flow. Turn the knob one way to increase flow, the other way to decrease.

//greg//

 

[RG1]

It has nothing to do with the rate of drop valve adjustment. You have a seal going bad in your valve body that controls the height of lift for the 3PH under the top cover. It's a several hundred dollar repair if you can't do it yourself. Get it fixed as soon as you can or it'll progressively get worse, faster.

 

[greg_g]

Try the (free) flow control knob before you undertake a possibly unnecessary repair. Lift cylinder seals go out all the time over in the Chinese tractor forums. But it's not discussed as often about John Deere CUTS, cuz they start with better quality materials in Georgia. If it in fact turns out to be a seal, I apologize in advance.

//greg//

 

[RG1]

Thing is, if it were the rate of drop valve being too open, it would drop back down right away every time he lifts the blade. Since he said it does it occasionally, it is in all probability a valve seal going bad. The fluid leaks past it until it gets too low in the lift cylinder to hold the implement up.

 

[Tx Jim]

But it's not discussed as often about John Deere CUTS, cuz they start with better quality materials in Georgia.//greg//

Really so JD CUT's have no mechanical/hydraulic problems???

 

[4310]

Is the "feedback rod" number 15 in that parts diagram? It looks like it should be fairly easy to adjust if it ever warms up around here.

I went out and played in the snow again today and it may be the lever slipping just a tad that is causing the 3PH to drop down. I adjusted the "stop" to set behind the lever so I could raise it up without it going into relief and I noticed that when the 3PH would drop it appeared that the lever was no longer touching the stop. It moved down maybe 1/4" so I bumped it back against it and it raised back up.

In case I'm wrong though, is there a picture of the seal that may be going bad?

Thanks

 

[greg_g]

If it's the same as on my 3720, the feedback rod acts sorta like a psuedo draft control. If this is consistent across the model line, the feedback rod should be responsible for lifting the arms under load - not dropping them. Did you not try adjusting the flow control knob? Or doesn't the 4310 have one?

//greg//

 

[Tx Jim]

Is the "feedback rod" number 15 in that parts diagram? It looks like it should be fairly easy to adjust if it ever warms up around here. Thanks

Yes feedback rod is parts key #15. If control lever is moving during operation then 3 pt hitch will also move.