L3400 3-point hitch adjustment

[smweatherman]

That's disappointing.
I've been following this thread. Early on you mentioned setting the plate-to-valve distance at 16mm when setting the set screw/poppet valve clearance. Have you continued to use this 16mm setting throughout? I was looking into attempting this on my MX4700 and thought I would start with both measurements in the middle of the ranges given in my WSM (16.15mm and 0.15mm).
It looks like this would have the same effect as decreasing your .006" set screw/poppet clearance as the pictures make it look like that plate is 'fixed' on the spool valve. (increasing the 16mm measurement without changing the set screw increases the set screw/poppet valve clearance measurement.
Is the plate parallel to the front of the valve, i.e. is that 16mm constant across the plate?
My mind twists in knots trying to keep track of everything going on, but I think starting where I was considering starting with the measurements would be in the wrong direction based on your results so far. It appears maybe when your spool valve is in the neutral position the set screw is activating the poppet valve just a bit requiring some pressurized fluid to keep the cylinder extended. My starting measurements would make this even worse, of course assuming everything else was identical.

Are we thinking the same way?

Good luck

 

[LD1]

I wonder if the few guys on here that managed to get the dealer to fix/adjust theirs to get rid of the jerkiness are having the same problems??

 

[Chilly807]

Have you continued to use this 16mm setting throughout? Yes, I haven't varied from 16mm

Is the plate parallel to the front of the valve, i.e. is that 16mm constant across the plate? Yes, the plate remains parallel to the front of the valve body at all times.

It appears maybe when your spool valve is in the neutral position the set screw is activating the poppet valve just a bit requiring some pressurized fluid to keep the cylinder extended. I think this is exactly what's happening. Another clue is that when the RPM is at idle, the load settles very slightly, depending on how heavy it is. When you bring the RPM back up to move, the load rises gently again. I'd probably be ok with that, but the shock when you open and close other valves is unacceptable to me. If the 3 point was the first valve in the system, it wouldn't be an issue. There's really no way to change the plumbing to do that since the valve dumps directly into the sump.


Are we thinking the same way? It's like we're joined at the head..:laughing:


Good luck

It's like thinking you've won the lottery, then noticing the date on the ticket is wrong.. I should have known it was too easy to be fixed like this, otherwise Kubota would have done it already.

Sean

 

[Chilly807]

I wonder if the few guys on here that managed to get the dealer to fix/adjust theirs to get rid of the jerkiness are having the same problems??

Thta's the exact same question I have. If theirs is the same, then there may truly be no easy way out of this. If not, then it can be fixed. I'll try digging around in the posts and find a couple that have been adjusted. I think kubotacres was one, and 360-something? had his done too. jokergerm seems to have moved on, so I doubt we'll get a response from him.

I'd like to see the same conditions on video o9f their tractors to be sure. I'll try to get another short video of mine before I tear it apart again so you guys can make a decision whether you want to go this way or not. What I find objectionable might not bother you at all.

Other than the jump after using upstream hydraulics and the settle on shutdown, the hitch is butter smooth.

What the constant flow of hydraulic fluid will do long-term I have no idea. It doesn't affect the speed of the hitch movement noticeably, although I think it must have some effect on it. There may be some heat buildup as well, it's hard to get objective numbers on that, particularly at -15C !

Sean

 

[teg]

Before tearing back into it, it seems to me that "Feedback Rod" *may* have something to do with it??? If the 3ph drops, that movement will be transferred back to the valve? Right? Just guessing on things to try...

I wish "someone with knowledge" would send you a note explaining what you need to do next!!!

 

[LD1]

Thta's the exact same question I have. If theirs is the same, then there may truly be no easy way out of this. If not, then it can be fixed. I'll try digging around in the posts and find a couple that have been adjusted. I think kubotacres was one, and 360-something? had his done too. jokergerm seems to have moved on, so I doubt we'll get a response from him.

I'd like to see the same conditions on video o9f their tractors to be sure. I'll try to get another short video of mine before I tear it apart again so you guys can make a decision whether you want to go this way or not. What I find objectionable might not bother you at all.

Other than the jump after using upstream hydraulics and the settle on shutdown, the hitch is butter smooth.

What the constant flow of hydraulic fluid will do long-term I have no idea. It doesn't affect the speed of the hitch movement noticeably, although I think it must have some effect on it. There may be some heat buildup as well, it's hard to get objective numbers on that, particularly at -15C !

Sean

It seems that the following members have had hitches fixed or improved by dealers.

TK1467 ...........last activity 2-10-12....29 posts
Unfinished..........last activity, yesterday
jokergerm.........may not be long gone, last activity 1-31-12
e30racer..........last activity 1-18-12

Perhaps PM one of them. They may have e-mail notification of new PM's. See if any of them have the "settling issue" of the hitch.


Here is e30racers post # 218 of that long thread

A couple of differences I now observe in my 3ph operation are as follows:

-the 3ph control handle is much easier to move up and down. I believe that to be due to whatever "adjustments they made in the linkage.

- whenever my bush hog is not all the way down and I start the tractor, as soon as the tractor starts the implement immediately raises up a few inches. It did not do this prior to having this work done so I'm guessing that this is due to the valve adjustments that were made.

So with the bushhog comment, it sounds like his "could" be settling and he not knowing it until he fires it up next time and then it raises back up?????

 

[unfinished]

Been watching this thread with interest. Sean, thanks for taking the initiative to do this.

I have not noticed much settling issues on mine. If I operate the loader valve I do not see any change on the 3pt hitch. When shutting down I cannot see any immediate settling. However, if (like quoted above) I do not have a 3pt implement resting on the ground (like several hrs or overnight) it will spring back to its original position, an inch or less. I just assumed this was the same affect as leaving the loader up in the air and having it creep down after a while.

The other thing I noticed with mine is tht it is not as fast to raise as before the repair,but I am ok with that tradeoff.

 

[LD1]

Been watching this thread with interest. Sean, thanks for taking the initiative to do this.

I have not noticed much settling issues on mine. If I operate the loader valve I do not see any change on the 3pt hitch. When shutting down I cannot see any immediate settling. However, if (like quoted above) I do not have a 3pt implement resting on the ground (like several hrs or overnight) it will spring back to its original position, an inch or less. I just assumed this was the same affect as leaving the loader up in the air and having it creep down after a while.

The other thing I noticed with mine is tht it is not as fast to raise as before the repair,but I am ok with that tradeoff.

Thanks for giving us an update. And sorry if there were any hard feelings that I called you out my name. But you seem to be one of the "few" that have gotten the issue resolved. And it appears without the side-effects.

I wouldnt be worried about settling when shitting off. I always lower stuff when shutting off anyway. But I think Chilleys main issue is the jumping while using the FEL. And if it is as I am think it is, I would not want to live with that either:confused2:

Hopefully with you, chilley, and others....maybe we can get to the bottom of this. If I were not using mine right now carting junk in/out of the basement for the remodel I am doing, I would probabally have mine appart in the shop by now.

 

[LD1]

Hey Sean.....or anyone???

Do you know if those specs you got are the same for the older model valves??

I decided to heck with it and tore mine appart just now. If it is supposed to be the specs you listed I am awe-struck....

For starters, that 47.5mm spec you listed on mine came out to 1.970" (50mm)

And then I set the gap to .630 (16mm) and I have a good 1/4" gap where you say should be .004-.008:confused2:

Just wondering if the old valves are the same before I tighten that much and re-assemble I notice mine appears to have an additional plate where you are measuring your .630". I wonder if mine is supposed to have a different spec as a result???????

pic attached

 

[LD1]

Well..I didnt feel like waiting, so I set mine and threw it back together.

That plate you see in mine that Seans dont have, I took my .630 measurment BEYOND that and set it to .007"

End result......Same as Seans. Hitch is smooth as butter but the 3PH responds oppositly to the loader controls. And more RPM's make it worse. And this is with a 700lb blade on.

Raise the loader (taking pressure/flow from the "system") and the 3PH drops until the loader valve is released and then the 3PH returns to normal.

Lower the loader (adding pressure/flow back to the "system") and the 3PH raises into the air:confused2:

With the loader raised, and the 700lb blade just barley resting on the ground and 2000RPM, when the loader is lowered....the blade raises about 5":confused2: That is until you stop lower the loader, then the 3PH will settle back down.