3-Point Hitch L-series Jerky 3PH - Jeff's homebrew repair.

[merlynr]

From my earlier post I found out that I too have somewhat jerky 3ph when moving it in small increments. So after 2 years of not noticing it I guess that it is what it is and I'm not going to worry about it.

 

[Chilly807]

From my earlier post I found out that I too have somewhat jerky 3ph when moving it in small increments. So after 2 years of not noticing it I guess that it is what it is and I'm not going to worry about it.

Most of us have done just that, too. To me, there's enough good things about the tractor to outweigh the negative of the jumpy hitch.
It's the kind of thing that's a deal killer if you discover it does that before you buy, or even shortly after in some cases.

 

[bigballer]

I don't even really notice this on my 3400 (now with 380 hours). maybe I am just used to it and have adapted my technique to overcome the jerk or mine is not affected as much as others are. What is more annoying to me is the a sticky PTO and HST pedal

 

[k0ua]

I don't even really notice this on my 3400 (now with 380 hours). maybe I am just used to it and have adapted my technique to overcome the jerk or mine is not affected as much as others are. What is more annoying to me is the a sticky PTO and HST pedal

My L3400hst was jerky as all get out, but the HST pedal and the PTO actuator lever both worked very well.

 

[s219]

For all the complaining I have done about the hitch, it's been a non-issue while grading my barn site recently. I have been using the heck out of my box blade, lots of up/down and adjustments, and have not had any issues. I couldn't even get enough jitters out of the hitch to shake off some sticky dirt! I'd almost think the problem went away (will have to try lifting one of my trailers, which is where it was obvious).

 

[k0ua]

For all the complaining I have done about the hitch, it's been a non-issue while grading my barn site recently. I have been using the heck out of my box blade, lots of up/down and adjustments, and have not had any issues. I couldn't even get enough jitters out of the hitch to shake off some sticky dirt! I'd almost think the problem went away (will have to try lifting one of my trailers, which is where it was obvious).

We often hear that some are much better than others.

 

[hugho]

Thank you Jeff for an amazingly well done and thought out fix. I am buying a used 3400 and your post was very useful.

*** I will return to this thread and fill in this post with a great more details as I get the chance.***

For now, you can watch this Youtube video and read the extended description.

Kubota L3400 - 3PH Action @ 2000 RPM - YouTube

Quick summary:

L3400 with extremely jerky 3PH (violent) with old YR909-00100 PCV. We bought the tractor used this winter, and were quickly and thoroughly disgusted by this fundamental problem. I dismantled and studied the PCV system and made the mods early this spring. Have been using the tractor like this all summer and am very happy with the result.

1. Disassembled the PCV and chamfered the spool control edges by ~200 um. This increased PCV response and reduced the violent jumps from 1" down to less than 1/4".

2. Added an external pressure compensated flow control valve ($~90 + lines and fittings). This reduced the flow to the 3PH system and took the violence out of the 3PH motion. It also reduced the lift speed though this is now adjustable. It did not affect the 3PH lift capacity or the FEL in any way.

I will fill in the blanks, and explain much more thoroughly later as well as show photo's and a part list of the install.

Cheers,
Jeff

 

[hugho]

jeff could you elaborate on your chamfer of the spool control valve. You removed 200 microns(?) from where exactly?

 

[Atlanta Panther]

Did Kubota ever fix this problem for the L3200? I have 200 hours on mine...long past warranty and had just put up with it. Being new to tractors when I bought it, I didn't know any better. I can certainly live with it and have since I bought it 5 years ago but it would be nice to have it fixed once and for all. I don't have the skills/tools necessary to do the mods suggested in this very good solution that the original poster put forward.

Any luck with Kubota?

 

[Chilly807]

Nothing in my case. Kubota corporate wouldn't admit there was a problem to begin with, so the dealership, although sympathetic, weren't willing to try to repair it without support from Kubota.
The only success I had was adjusting the position control valve to factory specs. It eliminated the jerky performance but introduced other issues that were worse.
A flawed design that the company refused to acknowledge.

 

[k0ua]

Nothing in my case. Kubota corporate wouldn't admit there was a problem to begin with, so the dealership, although sympathetic, weren't willing to try to repair it without support from Kubota.
The only success I had was adjusting the position control valve to factory specs. It eliminated the jerky performance but introduced other issues that were worse.
A flawed design that the company refused to acknowledge.

The last I heard from a Kubota rep in my district, was that the L3400 has a "standard" 3pt hitch, and if you want a Deluxe 3pt hitch and the characteristics that come with it, they have those for sale too. They are called Grand L's. They have a different 3pt valve. In other words, it is what it is. If you want more then trade up. I did. I traded for a DK35se Kioti. My L3400hst left the place in perfect condition, with pickup truck bed coating applied to the steel floor, I added SSQA which it didn't have when new, and it's nice very jerky hitch which it always had.

 

[Fallon]

The L3301 I test drove a while back had a pretty smooth 3pt. Operated a lot better then my L3200 did at the time. Maybe as good as my now L4060, not sure. My L3200 wasnt smooth, but not that bad. At least not enough for me to wory about it.

 

[ccsial]

I got my L3400 HST in 2005. I complained to the dealer about the jerky 3PH. They took the tractor in and replaced the valve with a ""new style valve" and it is much better now. There is a valve somewhere out there that is much better. I doubt my dealer would even know what they did 13 years ago and the service manager has since retired. I don't know if a Grand L valve is what they put in.

Dealers are not all created equal. I am lucky to have great one.

 

[daveknowshow]

so this thread started in 2011 and I read the entire thread. seems Jeff never finished explaining the mod. has there been any indication that the mod caused premature pump failure? any other issues or concerns?

 

[k0ua]

I think this quote from me years ago is still valid:

The last I heard from a Kubota rep in my district, was that the L3400 has a "standard" 3pt hitch, and if you want a Deluxe 3pt hitch and the characteristics that come with it, they have those for sale too. They are called Grand L's. They have a different 3pt valve. In other words, it is what it is. If you want more then trade up. I did. I traded for a DK35se Kioti. My L3400hst left the place in perfect condition, with pickup truck bed coating applied to the steel floor, I added SSQA which it didn't have when new, and it's nice very jerky hitch which it always had.

 

[bullbreaker]

I remember this thread it was a blast from the past , at least to me because I use to own a L3400 DT (gear) direct transmission . Seemed like this was an issue , as was a cable that controlled something which I cant remember rite now . I loved mine dang good small tractor .

Here was a thread I always keep pinned on my computer on bumping up the lift capacity .

https://www.tractorbynet.com/forums...-up-lift-capacity-l3400.html?highlight=cowboy

 

[k0ua]

I remember this thread it was a blast from the past , at least to me because I use to own a L3400 DT (gear) direct transmission . Seemed like this was an issue , as was a cable that controlled something which I cant remember rite now . I loved mine dang good small tractor .

Here was a thread I always keep pinned on my computer on bumping up the lift capacity .

https://www.tractorbynet.com/forums...-up-lift-capacity-l3400.html?highlight=cowboy

PTO engagement cable. Some people had trouble with them. I never did.

 

[daveknowshow]

seems like the thread original topic went unfinished. the topic was about jeff's home brew fix. what he did and how. seems jeff dropped off the planet and never updated the thread with any more information. it would be nice to know if this mod of jeffs had any negative results, ie: premature pump failure or other issue. these tractors are still being sold on the used market to many unknowing folks at a premium price point. I have seen l3800 l3200 l2800 l3400 model tractors selling for eighteen thousand and up used with no implements except a FEL. the first two pages of this thread talks about Jeff's Mod the rest is merely complaining about Kubota's denial. 26 pages of that which has been beat to death in other threads I'm sure. I own a l2800 myself one of the early models that has a jerky hitch. would be nice to know if this mod actually works with no long term side effects or damage before I try it myself. or before someone else does.

 

[rScotty]

seems like the thread original topic went unfinished. the topic was about jeff's home brew fix. what he did and how. seems jeff dropped off the planet and never updated the thread with any more information. it would be nice to know if this mod of jeffs had any negative results, ie: premature pump failure or other issue. these tractors are still being sold on the used market to many unknowing folks at a premium price point. I have seen l3800 l3200 l2800 l3400 model tractors selling for eighteen thousand and up used with no implements except a FEL. the first two pages of this thread talks about Jeff's Mod the rest is merely complaining about Kubota's denial. 26 pages of that which has been beat to death in other threads I'm sure. I own a l2800 myself one of the early models that has a jerky hitch. would be nice to know if this mod actually works with no long term side effects or damage before I try it myself. or before someone else does.

I imagine that Jeff thought the subject was finished. He did his mods and reported how they worked. Rather a nicely done job in all. He not only described what he did and how it worked, he listed the parts and reported everything that needed to be done to replicate his work. It would be nice to hear from him again... it's always nice to listen while someone clever does a recap.
But there's no reason to suspect that what he did would have any negative effects, so no reason there for him to follow up.
rScotty

 

[daveknowshow]

I imagine that Jeff thought the subject was finished. He did his mods and reported how they worked. Rather a nicely done job in all. He not only described what he did and how it worked, he listed the parts and reported everything that needed to be done to replicate his work. It would be nice to hear from him again... it's always nice to listen while someone clever does a recap.
But there's no reason to suspect that what he did would have any negative effects, so no reason there for him to follow up.
rScotty

not entirely true he did follow up with some pictures of the mounted valve but he did not follow up with regards to the work done on the valve under the seat that he took apart. that was the part I was curious about. as well as if there were any ill effects or issues long term. I do appreciate what he did share and hope it does work since I'm in the process of trying it myself.