SURVEY: Chattering 3 Point (going up)

[Bluegill]

There is internal adjustment in the 3 pt valve body. It could be has simple as that, or?
But it sounds like yours will get fixed for sure.

 

[ShaunRH]

I know I haven't adjusted mine since I bought it and it doesn't chatter, maybe I'll never adjust it now! I don't want to introduce the problem!

I normally bring implements up really slow when using the box blade (for a smooth finish in certain circumstances) so I haven't seen the dreaded chatter... yet, and that means, I'm leaving that darned adjustment alone! No Touchy!

 

[Bluegill]

I know I haven't adjusted mine since I bought it and it doesn't chatter, maybe I'll never adjust it now! I don't want to introduce the problem!

I normally bring implements up really slow when using the box blade (for a smooth finish in certain circumstances) so I haven't seen the dreaded chatter... yet, and that means, I'm leaving that darned adjustment alone! No Touchy!

The adjustment is a one time thing done during assembly. Not something that
should ever need adjusting if it's done right the first time. You have nothing to worry about.

 

[otter]

The adjustment is a one time thing done during assembly. Not something that
should ever need adjusting if it's done right the first time. You have nothing to worry about.

There is an external adjustment on the L3800 under the operators seat. Mine is stuck in it's current position.....since the three point works well I do not want to try and get it loose.

 

[North Idaho Wolfman]

There is an external adjustment on the L3800 under the operators seat. Mine is stuck in it's current position.....since the three point works well I do not want to try and get it loose.

The adjustment point you're referring to is the down speed adjustment, plays no role in the up movement, therefore plays no role in this issue.

 

[TexasBoy]

,,,, Its seems the best resolution is to get a part from the grand L series and install on standard L series. I can't remember what the part was, maybe a valve.

This issue has been hashed and rehashed ad nauseum and unless I missed something recent, I dont think there is any fix for the behavior of all the pre-2014 L-Series 3-point lift systems. There have been some bright persons design some external pressure controls to throttle the amount of hydraulic pressure the internal lift is receiving and therefore minimize the symptoms, but aside from that the OEM design is what it is.

 

[Bluegill]

This issue has been hashed and rehashed ad nauseum and unless I missed something recent, I dont think there is any fix for the behavior of all the pre-2014 L-Series 3-point lift systems. There have been some bright persons design some external pressure controls to throttle the amount of hydraulic pressure the internal lift is receiving and therefore minimize the symptoms, but aside from that the OEM design is what it is.

Yes, but more so on that other forum, with a couple very loud voices that jump in when ever the chance arises... Not as much talk about it here.

 

[CaveCreekRay]

UPDATE: The pressure out of the main hydraulic pump was good and stable as was the pressure across the valves they tested. They were supposed to disassemble the 3-pt drive Friday to examine seals. Awaiting an update Monday. So far, they will have had my machine 3 weeks by this Monday. With Christmas next week, its not looking good for the home team.

For many people, tractors are not vehicles of convenience, like a sporty car. They are practical machines we buy for a purpose to use in ranch or farm operations. We rely on them, just as much as our trucks and cars. What if Ford, or Toyota took your vehicle in and kept it for a month? Would that be an inconvenience? Heck yeah. Would their market share pay the price in reduced sales? Sure, and deservedly so.

Kubota USA owns this whole issue. There is absolutely no excuse to continue to manufacture a machine with a known defect. Calling it "normal" doesn't make it so. My neighbors John Deere has a 3-pt that operates as smooth as butter. And it has for the six years he has had the tractor. Does John Deere know something Kubota doesn't?

Evidently so!

The message to buyers is unmistakably clear: If you want a trouble free 3 point hitch, don't buy an L class Kubota.

 

[ShaunRH]

Not sure what's taking them so long. A 3 point issue should be over and done with unless waiting for parts. If the pressure is steady, then they have a RAM issue and it's likely a seal or machining problem. Either of which should be fixable in less than a day.

There's no reason for this to take 3 weeks.

By the way, that's not a Kubota problem, that's a dealer problem. Kubota is only a phone call away for the dealer and they could've had that back to you by now.

If you had bought a John Deere, your problems would have been different but you would have had them and had a machine worth less at resale time. It's not a great way to look at things when you have issue X and your neighbor doesn't. My L3200 doesn't have the problem either, does that mean that Kubota isn't flawed? No, it just means mine is working as designed.

If the factory has promised to own it, that's a good thing. If the dealer is taking forever, that isn't and I'd be complaining to Kubota about it, telling us about it doesn't do much unless you are asking us for a call in campaign... which we might help you with. Give us the dealers phone or email and we will deluge them!

 

[CaveCreekRay]

Shaun,

The dealership tells me they have to constantly wait for approval from Kubota to go to the next step. It took the dealer a week to get the machine checked out and to get the video to the Kubota regional guy. Then it took a few days to get the gauges on site to test all the components. That passed with flying colors. They received the approval Friday to open it up and were supposed to be doing that today. Bingham Equipment could have been a little more engaged to get it done faster, there is no doubt. Hopefully, I'll have it back next week, a month after I took it in. When I call now, the new service manager just hands me off to the service writer -as fast as he can.

For those of you in Phoenix considering a Kubota sold by Bingham, please take note: My tractor has been at Bingham Equipment for three weeks for two discrepancies, one minor and the 3pt chatter issue. If your business relies on your equipment, you better be able to handle business without your machine. Otherwise, you may go out of business.

 

[ShaunRH]

So, in the era of instant information, an amateur you-tuber can edit and upload 20 mins of video in a couple of hours and this dealership took a week to get a video to Kubota? Then they didn't have proper test gauges on site? Kubota gave them the okay last Friday and they are getting to it today?

Sorry, not buying the 'got to get approval for everything' sequence either. That dealer sounds really easy going, like, work 20 mins a day on a problem then move to next problem. I've dealt with dealers like that and avoid them like the plague once discovered. I think you might have a Zombie Dealer there... slow and will eat your pocketbook up as well as your time!

Well, she only went in for her first oil change but it was a Zombie Dealer! She came back looking like this!

 

[CaveCreekRay]

HEY! That looks almost like the tractor I bought!!! (shudder)

Great news. Dealer called yesterday...

Once cleared in, the hydraulic mechanic dismantled my control valve and piston. He said at roughly 200 hours of use, my piston bore for the 3-pt actuator still had all the X-swirls marks in the piston sleeve from manufacturing. Zero wear and pristine condition, as you would expect. He said the piston "ring" was a metal ring with teflon on either side. All pristine.

Something in the valve assembly was held in by a bolt and a lock washer. This had worked loose. As a result, there was a misadjustment in how the valve operated. In fact, with this internal adjustment out of whack, the valve actually started to wear and was "clicking" at one point in its travel. They took loads more pictures for Kubota and Kubota has sent them an entire new valve assembly: $900. This could be a reason why Kubota doesn't want a massive re-call. It would cost a bundle to repair across 1500 tractors.

The service writer said the tech believes its either a manufacturing problem (out of adjustment slightly at the factory) or a poor design because this part loosens up over time and screws up the adjustment. I am going to suggest Loctite.

All this information was second-hand through the service writer. I am going down today to look at the valve and take pictures which I will upload here. Though I may be incorrect, it sounds as though this problem "might" be resolvable if you take the valve apart and adjust it yourself. I'll confirm that when I see the assembly and look at the schematic today. The part is flying in today and will be installed and checked out. It it passes their tests, they are loading the tractor up and hauling it home tomorrow morning. I sure hope so...

Stay tuned.

 

[Burt]

HEY! That looks almost like the tractor I bought!!! (shudder)

Great news. Dealer called yesterday...

Once cleared in, the hydraulic mechanic dismantled my control valve and piston. He said at roughly 200 hours of use, my piston bore for the 3-pt actuator still had all the X-swirls marks in the piston sleeve from manufacturing. Zero wear and pristine condition, as you would expect. He said the piston "ring" was a metal ring with teflon on either side. All pristine.

Something in the valve assembly was held in by a bolt and a lock washer. This had worked loose. As a result, there was a misadjustment in how the valve operated. In fact, with this internal adjustment out of whack, the valve actually started to wear and was "clicking" at one point in its travel. They took loads more pictures for Kubota and Kubota has sent them an entire new valve assembly: $900. This could be a reason why Kubota doesn't want a massive re-call. It would cost a bundle to repair across 1500 tractors.

The service writer said the tech believes its either a manufacturing problem (out of adjustment slightly at the factory) or a poor design because this part loosens up over time and screws up the adjustment. I am going to suggest Loctite.

All this information was second-hand through the service writer. I am going down today to look at the valve and take pictures which I will upload here. Though I may be incorrect, it sounds as though this problem "might" be resolvable if you take the valve apart and adjust it yourself. I'll confirm that when I see the assembly and look at the schematic today. The part is flying in today and will be installed and checked out. It it passes their tests, they are loading the tractor up and hauling it home tomorrow morning. I sure hope so...

Stay tuned.

CCR,

Try to get the numbers off the valve if you can.

Your story is somewhat similar to mine. Fixed now but then it's as if you're the one causing the problem at first.

Burt

 

[CaveCreekRay]

Grab a cup of coffee... this may be a long one.

Part 1 (Sorry: For some reason this site counts the number of pics as twice what I really post and limits me so I'll split it up...)

Here is the valve assembly for the 3-pt...

The Red arrow point to the valve that ports pressure to the piston.
The Pink arrow sits over the " pressure bypass valve"

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Here is a movie of how it works: The tech is turning a tool taking the place of the 3-pt lever. When you move the lever, the control bar (the silver one) gets moved by an arm that pivots on a rod on one side of the case, porting pressure to the piston. As the piston moves, a position rod moves the arm on the other side of the case, rotating that arm and rod and that moves the other side of the bar out, which cause the pressure bypass valve to start bypassing hydraulic fluid into the rear end case. Notice the "glitch" on the center valve...


http://vid307.photobucket.com/albums/nn297/CaptStark/Kubota%203-pt.mp4

When your engine is running and your 3-pt is still, the bypass valve has stolen the fluid and pressure from the positioning valve and it is dumping into your differential, keeping it all lubed up nicely. (Mine is an HST... I assume the DTs work the same with Hydraulic fluid in the rear end...) Unused fluid constantly rains in there from the bypass valve as long as the engine is running and the positioning lever is not moved, demanding up pressure. When you move the 3-pt lever down, the bypass valve releases the pressure and fluid on the back side of the 3-pt piston and the piston moves, allowing the 3-pt arms to drop.

That valve assembly pictured above is actually upside down and bolted to this, the rear end of the tractor... In the picture above, you can see the rear end cover that bolts to the hole in the differential right under the seat... It was nice seeing a squeaky-clean differential. Nice gears. The transmission is immediately to the right of the rear end in this picture, under the scraper tool.

 

[CaveCreekRay]

Part 2: How the 3-pt works...

Looking at this picture again, you can see the two valves that slide in the valve block. The center positioning valve ports pressure right into the 3-pt activation piston located just above the valve (in this picture on the other side of the control valve). Just remember, what you are looking at is my rear end top cover laying upside down on a workbench with the 3-pt doo-dah valve screwed to it! You'll see the actual piston in the next picture. Oh, and by the way: Kubota hand laps all these valve bodies and pistons. There are zero parts available for this body. The assembly runs $900. Could you have a valve rod machined? Probably, for a lot less than $900...



Look for the lever control arm on the lower side. On the top side is a nearly identical arm that is moved by the Position Arm which is moved by one of the 3-pt lift arms. The upper arm simply tells the control valve where the 3-pt is by matching the position of the control lever. That rod that runs between them is the Valve Control Rod and its function is to keep the pressure flowing to the piston until it reaches the desired position. Its crooked (not 90 degrees) right now which is telling the control valve to keep porting pressure to the piston which would eventually move the Position Arm to a point where this Valve Control Rod would return to 90 degrees and the Pressure Shutoff Valve would steal the pressure and stop the piston movement.

As the 3-pt arms raise, the Position Control Arm moves the upper side of the Valve Control Rod until it is again 90 degrees to the case, at which point the Pressure Cutoff Valve starts stealing the pressure and finally ports it all in a spray that rains down on the differential which is actually bathed in fluid. If the Valve Control Bar is all the way out, the fluid is ported to the piston in the full up position. If that bar is in close to the Valve Body, the 3-pt is full down.

In this picture, in the foreground, you can see the 3-pt position Control Rod that is attached to one of the 3-pt arms... His blurry hand on the other side is on a punch that replicates the 3-pt control arm you use to run the 3-pt...

[/URL][/IMG]

You can see above, as the 3-pt arms move, the Control Rod moves the other side of the Valve Control Rod and that moves the valve. Can you Say "Rube Goldberg?" It is essentially a mechanical computer that resolves the difference between two rod positions to control hydraulic pressure.


This picture shows the 3-pt Piston and Connecting Rod (other side of the case)...

[/URL][/IMG]

Here is a shot with the connecting rod out showing the bottom of the piston...
You can see the valve body sits right next to the 3-pt actuator piston and hydraulic fluid under pressure from the middle valve passes through a port cast in the housing to the piston. That piston picks up nearly a ton of implement.

Click the small picture below to watch the video...



Now, watch the movie again and it will make more sense....

 

[CaveCreekRay]

Part 3: What The Heck Was Wrong With This Dang Thing (We Think)

If you watch the video, as the 3-pt control arm was moved to pick up my implement, the Pressure Control Valve started opening to port pressure to the piston (moving out, in the picture, to the left), just like it was supposed to. About half way the control valve rod glitches (stops for a second and then snap to catch up) like something was binding inside the assembly. My tech thinks something is snagging the valve over one of the ports, probably the one to the 3-pt actuation piston. Best he can tell, the valves are all steel and have no plastic or rubber seals.

Also noted, one of the fasteners to the Valve Control Bar (The shorter bar the Valve Control Rod moves) was a tad loose. That screws up the whole positioning which is really critical to get these valves to work correctly. This may have put a bind on the center valve but whether it did will be determined when Kubota tears this valve body apart.

The tech said, they should be adjusted per MM, when going down, to very precise measurements. Could you do it yourself? With a maintenance manual, most likely. But, if your valve is sticking, that may require getting the valve honed and or re -manufactured.

One side:

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And, the other:

[/URL][/IMG]

The new valve goes in in about an hour. If it checks out, I should have my tractor back tomorrow.

I had a nice talk with the lady at Corporate for Bingham Equipment and she acknowledged that they could have shaved quite a few days off this effort. The Service Manager was brand new at this location and the Service Writer had been with them about six months. They were wary of the problems in dealing with Kubota. If you don't follow Kubota's diagnosis plan to the letter and do that and no more until they approve it, you run the risk of getting your repair denied. They did not want to risk that though they could have pressured Kubota for faster response times. Hey, I am satisfied by talking to the tech that he has found the problem. How often can you go out on the shop floor and actually look at your machine in pieces and have its operation described in detail? Most places won't let you anywhere near their service bays. And the fact that they picked it up and dropped it off no charge, makes the delay a little more palatable. And, it made my decision to buy the extended Kubota Warranty that much easier. For about a buck a day, I am covered for everything but the FEL for two more years and for four more years on drive train. After watching a defective valve body, about the size two packs of cigarettes, malfunction and, knowing it was a $900 part they were picking up, that made the decision a little easier. If the new valve body goes goofy again, I suppose they would pick it up but, maybe not.

Can't wait to get the little orange piggy home and get back to work.

One last note on warranties...

I am not usually a warranty person. After talking to the Service lady at corporate, she encouraged me to get it for the tractor. She said they recommend people never get the extended on the FEL because the warranty is more than any single part. On the tractor, one service (like mine today) could pay for the warranty. It ran $1300.

 

[CaveCreekRay]

Just got back from the dealer... They wanted me to be the final quality control before they returned it. The technician and Service Writer spent 40 minutes going over all kinds of stuff with me while I was there. The tech even put new hydraulic filters on because the case had been open -but covered, for a day.

I was able to pick the box scraper up consistently 1/4" to 1/2" very smoothly. A tiny bit of surging near the top but nothing to worry about. The control in the lower half is where it really matters.

The tractor should be dropped off at my place tomorrow around 7:30. Can't wait. I think the dealer (Bingham) did a very good job. Coulda been a little quicker but in the end, a week won't be remembered if the machine keeps working properly. That is what matters.

 

[sheepfarmer]

Wow!!!!! Congratulations, thank you for all the info, and Happy Holidays!

 

[CaveCreekRay]

Thanks!

And by the way, there was a 2000 Ford New Holland 3-pt in pieces on the table next to mine and it is essentially identical in operation to the Kubota valve and control assembly.

 

[TexasBoy]

Thank you for going to the trouble of the write-up with pictures.

Would you mind making a video of how your 3-pt behaves now with a heavy implement, and being raised very slowly? Would love to see the result of all your efforts.