3-Point Hitch Another L3700 with Jerky lift

[k0ua]

Originally Posted by Chilly807 View Post
Has anyone tried raising the loader while also raising the 3pt? Someone mentioned that earlier in the 2009 thread, but did we ever follow up? If that works, that means that a slower flow of oil (caused in that case by another demand on the pump flow) has the desired effect. Ergo, a restrictor will work provided it doesn't cause other problems.

here are my findings: yes I agree at 1400rpm.. no difference in raising the loader at the same time, also no diff at 2000 rpm. BUT. at idle the problem is 100 percent better. almost totally smooth on raising oof the 3pt in small increments. It is a really noticeable improvement. Also noticed the 3pt seemed to raise about as fast as it normally does, maybe just a little slower. Also notice that if you engage "curl" instead of "lift" of the bucket, the rear 3pt will not raise at all as long as the "curl" function is engaged. I think the flow will have to be severely restricted to accomplish the goal of a smooth raising of the 3pt. Mine now acts about like a 1/4 inching valve. it jerks and jumps even at 700 rpm if you try to raise the lift by slowly moving the lever. One problem is that it almost seems from the jerking it sets up a "feedback" in that it moves your body with the first jerk which can set up a movement in your own body causing you to bump the lever again, causing a train of "jerks". All this being said, I dont have a problem with the way it operates. But if I was trying to operate a boom pole or PHD on the back, I could really see that as a problem. I don't own either. I would be interested in hearing about a "fix"
James K0UA

 

[Chilly807]

This is interesting to me. In 2005 When I complained, the dealer sent a tech to my home and he looked at it and said "that is not right". I got a call later from the service manager that he found something on the Kubota web site and there is a fix.

I suspect the dealer only looks at the service bulletins, etc if they have a complaint, and some don't even do that. I have faith that mine will do whatever they can without modifying the tractor to make it work as smoothly as possible.

They picked up my tractor and fixed it for free. I was not there to watch but they removed the seat and the whole top of the housing and changed a valve. It was much better but not perfect. I could live with it now. Before it jumped a full inch at a time.

I think that none of the 3400s out there are truly smooth. From the videos I've seen on the web, even the "after" videos are a long way from ideal. Mine is livable as well, but if there IS a fix for it I'd like to get it done.

Or are the new ones working like mine is now but still not considered smooth enough by many owners.

I think this is the situation we have now, even with the brand new 2800/3400/3700 models. Probably Kubota has gone as far as they're willing to without making major changes. If we knew what the "major changes" would have to be, at least some of us would be willing to try it, provided it's even curable. It may truly just be the nature of the beast through design problems. I think if a valve change would fix it completely, Kubota would have done that a long time ago.
I suspect they will change a valve to improve the "chatter" if a customer insists on it, but they either haven't researched the issue to the point of resolving it completely, or the problem can't be eliminated without redesigning major components in the 3pt system.

From a corporate standpoint, some problems are better to leave alone. It's OK to fix a few tractors to keep the customers happy, even if it's expensive to do, but multiply that cost by the number of that particular model sold over a 5 year period. It's hard to keep an appetite sharp to fix them all when your profit margin for that model is out the window, or worse, in the red. In other words, if it's workable and you're not getting sued for injuries and damages, leave it alone as much as you can.

Sean

 

[k0ua]

I think this is the situation we have now, even with the brand new 2800/3400/3700 models. Probably Kubota has gone as far as they're willing to without making major changes. If we knew what the "major changes" would have to be, at least some of us would be willing to try it, provided it's even curable. It may truly just be the nature of the beast through design problems. I think if a valve change would fix it completely, Kubota would have done that a long time ago.
I suspect they will change a valve to improve the "chatter" if a customer insists on it, but they either haven't researched the issue to the point of resolving it completely, or the problem can't be eliminated without redesigning major components in the 3pt system.

From a corporate standpoint, some problems are better to leave alone. It's OK to fix a few tractors to keep the customers happy, even if it's expensive to do, but multiply that cost by the number of that particular model sold over a 5 year period. It's hard to keep an appetite sharp to fix them all when your profit margin for that model is out the window, or worse, in the red. In other words, if it's workable and you're not getting sued for injuries and damages, leave it alone as much as you can.

I think your are absolutely right:thumbsup:
James K0UA

 

[teg]

YouTube - Low rpms bucket of water.AVI

YouTube - High rpms bucket of water.AVI

I thought that it would have been smoother but it's not. This is 2005 L2800 HST with the replaced valve... below is the water level, before, after the low rpms and after high rpms. Still can not get over the fact that you move the handle for the 3ph but it doesn't do anything until you hit #4 or 5...

 

[Chilly807]

I'd call that pretty good compared to most of them I've seen. If I get a chance, I'll try that with mine from the PHD boom. I'm pretty sure it'll be worse, mine is a 2009 gear drive.

Sean

 

[k0ua]

I thought that it would have been smoother but it's not. This is 2005 L2800 HST with the replaced valve... below is the water level, before, after the low rpms and after high rpms.

Thats better than mine, unless I am raising the loader at the same time, on low rpm then it is quite good.
james K0UA

 

[Tomtint]

I have a L3700 with 16 hours on it, I just brought it to the dealer for the jerky hitch ( bounces almost enough to get the front tires off the ground) and they said they have never seen that problem before.......ok. They agree something is not right and If i drop it off next week they will look into it

 

[teg]

Sounds like kubota might have "other" jerky issues... that or they went back to the old valve. :confused2::thumbdown::mur:

 

[Chilly807]

Yes, this is the second tractor this week that's had unusually bad control over the 3 point, both Kubota L series.

Sean

 

[daveknowshow]

I recently did a video on this and the work around options Kubota Jerky Three Point Fixed??? MAYBE .....?!?!? - YouTube

 

[k0ua]

I recently did a video on this and the work around options Kubota Jerky Three Point Fixed??? MAYBE .....?!?!? - YouTube

Dave, one thing this scheme will for sure do because of the fact you now have more back pressure in the system because of the restriction you have added in the form of the "diverter valve" is a higher running fluid temprature. Take your temp gun and make some long term measurements of fluid temp with the diverter valve opened all the way towards the power beyond port (lowest restriction) and take some measurements with the diverter valve diverting some of the flow. You need to do this over a long term. Whether this is enough of a tenprature rise to be significant, I don't know. But there will be some temp rise by definition because you have added more restriction to the fluid flow path which raises temp.


I solved the 3pt. jerky hitch problem on my Kubota L3400 by trading it in on my Kioti. problem solved once and for all. I spent a lot of time on the phone with dealers and finally the Kubota regional rep, and the bottom line was and IS, if you wanted a Grand L and its smooth 3pt hitch you should have bought a Grand L. The "Standard L" series 3pt hitch works just like Kubota designed it to work (jerky) and it is not a defect, it just is what it is. To use an old cliche.

Dave this is a pretty old thread and an old can of worms you have reopened there fella.