Jerky LSeries 3pt Hitch Fixed

[Chef Pa]

Chef Pa, I'm one of those who was all ready to get an l3700, but won't unless the jerky hitch problem finds a solution on these pages.

Mike

Mike,

I'm right there too. Last thing I want to do is bash Kubota - I'm just an observer here and have no direct experience with the problem. From what I've seen in the videos though, the risk isn't worth it to me.

Greg

 

[TDVT]

Downloaded the L3400 hydraulic parts diagram last night & spent some time looking at all the pieces.

While I have a good bit of mechanical experience, I don't have much in the way of hydraulics but from my perspective (I don't know any better) the feedback rod is an obvious external adjustment. I looked this AM & mine is marked with paint across the locknuts. Factory marks or dealer setup?

At least one of the recent theories made reference to the feedback connection from the lift arms to the valve. I imagine there is a spec to set it to, but do the dealers actually check &/or reset it?

I am thinking of the many of us who didn't know we had suspension seats as they are almost always delivered seized up.

Has anyone fooled with the feedback rod adjustment?

 

[TDVT]

Has anyone fooled with the feedback rod adjustment?

Well a little extra Google-ing answered my own question.

I guess that rod adjusts lift arm max height. Found posts from 6 years ago detailing the adjustment, I didn't realize the quest had been going on that long, I don't recall ever seeing that thread.

Oh well.....

 

[Goog]

I am one of the original owners from 2005 with a L3400 HST when you had to wait to get one. It amazes me that Kubota is still selling these tractors with this problem. I had to go to the Kubota rep to get my valve replaced under warranty. In hindsight I should have bought a Grand L or a green tractor. Brian

 

[Leejohn]

Here is how the valve works and the adjustments on it. This is out of my old L3010 tractor manual. It worked real good. The L3130 I had and my L4240 have different valves. The setting could my be alittle different, but it's a good start.

 

[Leejohn]

Read the part that has to do with the lift, about the poppet valves. If the adjustment are right, then these valves are sticking or have the wrong springs or the springs maybe could of been put in the wrong spot. Does that make any sense??

 

[jokergerm]

well i was driving home last night and i saw this goofy looking older guy working at this sharpening place and guess who it was???

it was terry, im going to talk to him this week when i get some free time..

 

[rScotty]

Has anyone given any thought to the fact that maybe this "valve" is not the problem? My B-Series exibitted the exact same issue with the hitch being "jerky". The problem was/is the way the hydraulic lines were routed from the factory. Kubota has "quietly" come up with a kit that re-routes the return line coming off the steering box. Fluid cavitation causes the "jerky" lift operation so by re-routing the return line they corrected the issue 100%. Kubota helped me with the repair even though mine was way out of warranty. I know the B and the L are two different tractors but the symptoms are exactly the same. Perhaps the tractor that was fixed had an unapproved fix that had nothing to do with a valve so the dealer would rather remain silent. I think the story of the valve being out of adjustment or out is tolerance is a cover to keep the customer happy and the dealer out of trouble for doing an unapproved fix.

Well, we can only hope that isn't the case. I do know for a fact that upgrades without the customer's knowledge or approval being required are common in some machine industries nowadays. Approval is now taken for granted. I don't believe that came about because of any intent to deceive. Probably it just seemed the best and easiest course. But it makes diagnosis from a distance that much harder.

One thing you've made me curious about is whether this is a design problem across several model lines or just a few. So far I've heard about the B, L, and M. Of these there seem to be more cases of problems with the L. And just how widespread are these problems? We do tend to hear a squeaky wheel and think that all the wheels are squeaking.... Could it be that most of the Ls have 3pts that work very smoothly?
rScotty

 

[WayneJessie]

I find Wayne Jessie's post interesting, especially if the 2nd generation valve, 3rd generation valve or whatever they're up to currently, is shared by different models when they don't necessarily share the hitch problem.

I don't know how the lines are routed on the L tractors with issues, but I wonder what they changed on Wayne Jessie's B? Fewer bends, larger pipe, etc?

I know exactly what was done because I put the field repair kit in myself. Kubota paid for the parts but since I own my own auto repair shop I chose to install it myself. The cavitation issue is caused because the factory return line coming off the steering gear is routed into the suction line just before it enters the pump. This caused fluid cavitation which would cause "irratic or jerky" hitch function. Thre field fix consists of these parts: A revised metal tube assembly that fits on the steering gear, a new transmission top plate that has a fitting made in the top of it in order to accept a fluid return line and the needed fluid hose to route the fluid return to the trans instead of to the the pump. It corrects the issue 100%. I just do not think this valve is the culprit...yet. My experience with Kubota has been very good. I have three of their tractors and they are solid machines given the number they produce. Given some of the horror stories I have heard of some other brands, I am quite satisfied.

 

[BlacknTan]

I know exactly what was done because I put the field repair kit in myself. Kubota paid for the parts but since I own my own auto repair shop I chose to install it myself. The cavitation issue is caused because the factory return line coming off the steering gear is routed into the suction line just before it enters the pump. This caused fluid cavitation which would cause "irratic or jerky" hitch function. Thre field fix consists of these parts: A revised metal tube assembly that fits on the steering gear, a new transmission top plate that has a fitting made in the top of it in order to accept a fluid return line and the needed fluid hose to route the fluid return to the trans instead of to the the pump. It corrects the issue 100%. I just do not think this valve is the culprit...yet. My experience with Kubota has been very good. I have three of their tractors and they are solid machines given the number they produce. Given some of the horror stories I have heard of some other brands, I am quite satisfied.

This is good to know!

But, my question is this... Why does new production have the same issue if the fix is so simple?
Why doesn't Kubota do it directly from the factory?