L3400 3-point hitch adjustment

[LD1]

This is really frustrating.

Thats the whole point, the frustrating part is the deniability.

The L3400 has only been around for 7 or 8 years now and how many valves have they tried?????

That tells me they must have known it to be a problem.

And instead of wasting a lot of money, tech labor, customer confusion, why not just say "We know the valve is jerky, and nothing can be done short of replacing the whole unit with a better valve. We arent going to do it, but if you (customer) want the better valve and want to spend the money for it, thats your choice. But dont waste your time or your dealers time. Because nothing can make it better."

An another really frustrating part is that there are dealers on here (kubota dealers) who refuse to participate in these threads to shed some light. All they (those dealers) will say is that the havent seen hardly any with a jerky hitch. And the few they have seen were corrected 100% by adjusting the valve, without giving any details at all.

And maybe that is the case with the newer valves. who knows. But how many L3400's were sold with the older valves like mine that CANT be adjusted to correct the problem because they lack the "taper part" on the spool.

Not sure where the L3400's started, but mine is SN 61xxx. So I am guessing thousands out there with an in-curable jerk.

 

[kubotacres]

I'm curious since mine has been fixed, if I would have issues, IF i decided to purchase a FEL...However I have the newer valve on the L3200. I don't plan on buying one, but just curious.hmmmmm

 

[murphy1244]

How much is a new valve?? Just asking..

 

[LD1]

I'm curious since mine has been fixed, if I would have issues, IF i decided to purchase a FEL...However I have the newer valve on the L3200. I don't plan on buying one, but just curious.hmmmmm

The issue with the FEL effecting the 3PH is due to the dynamic balance. When in dynamic balance....ANYTHING that changes pressure or flow effects the hitch.

So to answer your question.....does the hitch move at all when going from idle to max RPM rapidly, or when shutdown, does the hitch drop at all??

It the answer to both is NO, then NO a FEL would not effect the hitch.

How much is a new valve?? Just asking..

Just a wild guess, but probabally $600-$800 for just the valve.

 

[kubotacres]

The issue with the FEL effecting the 3PH is due to the dynamic balance. When in dynamic balance....ANYTHING that changes pressure or flow effects the hitch.

So to answer your question.....does the hitch move at all when going from idle to max RPM rapidly, or when shutdown, does the hitch drop at all??

It the answer to both is NO, then NO a FEL would not effect the hitch.
.

I doubt I'll get a FEL for the my 3200. However my hitch doesn't drop or move at any occasion unless I adjust with the lever.

 

[timberland]

Thats the whole point, the frustrating part is the deniability.

The L3400 has only been around for 7 or 8 years now and how many valves have they tried?????

That tells me they must have known it to be a problem.

And instead of wasting a lot of money, tech labor, customer confusion, why not just say "We know the valve is jerky, and nothing can be done short of replacing the whole unit with a better valve. We arent going to do it, but if you (customer) want the better valve and want to spend the money for it, thats your choice. But dont waste your time or your dealers time. Because nothing can make it better."

An another really frustrating part is that there are dealers on here (kubota dealers) who refuse to participate in these threads to shed some light. All they (those dealers) will say is that the havent seen hardly any with a jerky hitch. And the few they have seen were corrected 100% by adjusting the valve, without giving any details at all.

And maybe that is the case with the newer valves. who knows. But how many L3400's were sold with the older valves like mine that CANT be adjusted to correct the problem because they lack the "taper part" on the spool.

Not sure where the L3400's started, but mine is SN 61xxx. So I am guessing thousands out there with an in-curable jerk.

My serial # is 57809 and I am not even confident that buying a new valve would fix the problem, at this point>

 

[Chilly807]

By the middle of the weekend I should be able to try a few more adjustments and see how good I can make it. We're supposed to get some more snow on Saturday, so I need an operating tractor by Sunday morning at the latest.

I know the older valves (Type 2) were considered worse than the newer style (Type 3). So, by trying to fine tune my Type 3 valve I'm hoping to both get mine to be better than it was, and to be able to give you guys some idea if it's worth shelling out more cash for a new valve, or even taking the tractor apart to be fine-tuned if you already have one.

In it's original condition mine was obnoxious, but livable. I just don't want to live with it if I don't have to.

I think the reason the L series has this problem is the 3-point design is flawed somehow, so a valve that's normally "good enough" isn't in this particular case.

Reducing the set-screw gap from 0.045" to possibly 0.035" should make a big difference in the amount the hitch jumps. If I can be reasonably sure it's stable and won't hunt up and down I'll leave it like that for a while and try it.

Moving the set screw from 0.026" gap (wild hunting) to 0.020" gap (almost perfectly stable but settling) isn't much of a change dimensionally speaking for quite a difference in performance.

I'm quite sure the adjustment range will have results that go from a) smooth but settling, to b) hunting and unstable, to c) jerky but not settling. I need to find the middle ground between the last two conditions.

If I'd known how much the hitch would settle and then jump back after using other hydraulics, I would have tried this setting before re-assembling everything.


Sean

 

[Caseyb1]

Really appreciate all the work Sean.

Casey

 

[Chilly807]

I don't mind the work, it's the kind of thing I like to get into anyway. I was really happy after the first adjustment and the lift was super-smooth, which turned into a rotten apple when I noticed the side effects that were part and parcel of that adjustment.

I'm still hopeful for a "silver bullet", but I also realize that the chances are getting less with every experiment we try. I should know something late today or tomorrow, I'm planning on taking it apart later today.

First move is to set the "spool joint to plate" adjustment to spec, it is 1 mm over the manual recommendations now. I think the only effect that will have is the lift will raise to a higher or lower spot in relation to the scale on the lever bracket, which will necessitate a re-adjustment of the feedback linkage.

If that's the case, then I'll try decreasing the set-screw clearance to less than the original setting to see if that makes the "jump" smaller when the lever is moved. It should to a certain degree, the limit to that adjustment option will be when the lift starts to "hunt" up and down by itself. I know it does it to a mild degree at 0.030", and it's violent at 0.026".

I doubt I'll get it really smooth, but any improvement is welcome at this point.

Sean

 

[k0ua]

Sean, You are doing great work... I have this sinking (and stinking) feeling that the people who have been told that their valve was adjusted to be non-jerky **might** have been lied to and that the dealer actually replaced the valve to ones like mine. I think if you can't find that sweet spot, I'm going to assume that those with "adjusted" smooth valves were duped into thinking that they can be.

Any one with an "adjusted" valve, willing to open it up and confirm the valve? and if it *IS* the original valve, take some careful measurements? THAT would be AWESOME!!!

That would be awesome to really know what was done and how it was done. This dealer I am working with thinks if I have the late model valve that it can be adjusted without replacement. He did ask for the serial number of the tractor first thing. Sean we all appreciate the work you and LD1 and others are putting in on this. It is a heck of a thing when we have to rely on customer's to gain knowledge of this problem and the possible resolution, instead of the manufacture being the one to guide us to the proper course of action. However it is not unprecedented. In my line of work, (working with phone and data products) This attitude is pretty common. (problems? what? we got no stinking problems!) I have over the years came up with fixes and work around's for several pieces of equipment myself that the manufacture initially denied and came out with a bulletin on later. Of course these "fixes" I speak of are software/programming fixes not tearing down a piece of machinery and learning how it works and coming up with ways to make it work better. I just don't have the skill and experience to do this. So again I applaud everyone's efforts and you guys are doing a great service to the rest of us in educating us about this problem and seeking a possible resolution. Thank You

James K0UA