NX6010 hydro transmission issues

[MinnesotaEric]

Well, they said they are working in it, so I will wait and see what they might come up with... Surely they are considering all options..

As per our phone conversation. Diagnostic wise look into:

1) Hydro PSI check.
2) Can machine tooling stuck somewhere cause this?
3) Can the wrong type of hydro fluid cause the lag?
4) Can a malfunctioning HST sensitivity dial cause the lag?
5) Can whatever mechanism that protects the engine from stalling, if it is hanging open just a bit cause this problem?
6) Can a lying sensor or weak return spring or stuck solenoid or HST software glitch cause this?

I don't have access and I've never seen how robust Kioti's diagnostic software is, but consider that the tech needs time to work through this problem (especially if on a witch hunt trying to find machine tooling after deciding that all the sensors claim to function but clearly the response is failing to react as expected).

Also Joe, drive another NX HST to get a sense of how they react. I think my tractor reacts relatively quickly. There is a moment of dead space between forward and reverse, but as a tech, I figure that time is there so the transmission doesn't try to do two directions at once and exists when hydraulic pressure to go forward and hydraulic pressure to go backward is equal as demonstrated in the simple green animation below.

 

[MinnesotaEric]

FWIW, I found a cool, practical explanation how HST transmissions work.

 

[kapper]

Well, after reading over your post yesterday Eric about how you've experienced a similar sensation when you had the anti stall on, I did some self testing today. I've come to the conclusion that the tractor is operating as it is supposed to be... I did 2 things today that convinced me of that. First, after you mentioned that when you had the slipping pedal that you let off the pedal and it kind of re-sets itself. I tried that once when it started slipping and low and behold, it worked. I then figured out that I was most likely trying to operate the hydro TOO quickly from reverse to forward and vice versa. Then, thinking back on when I've had the issues it seemed to always be when I was doing 'active' work, mostly loader work, when I am very quickly moving forward and back.

So, I'm thinking that it is just the design of the Kioit hydro and there is just that pause that I need to wait for a split second before punching it forward. Do I like it? No, not really, but that is probably because I am so used to my John Deere, which literally has ZERO pause, zero slip, none, nata.... So I found that when I pause for just a second and then hit forward, then It does not seem to slip at all.

The second thing I did was play with the calibration. I tried several different ways of calibrating the transmission. What I found out was that I could 'cheat' the pedal travel by calibrating the forward travel to max out at only 3/4 of the way depressed, instead of all the way down. What this did was to compress the power applied to the transmission in a shorter time, which generated noticeably more power in a much shorter time span. This was far more noticeable than that adjustable travel switch they have on the dash. So for users like me, who do a lot of quick to/fro movements, this seemed to help. If anyone has in interest in learned the calibration sequence, I can help

I also learned that if I tried to shorten the pedal even more, like only half way down, that it starts to mess up the motion as you'd get this weird power surge as you let off, plus it was just too much power, too fast. So, I believe that I will simply have to adjust to pausing a moment when hitting the hydro pedals. I did some serious cutting work and grading today, and was very impressed with the power of that thing to be sure. So, I will have to re-learn a little and adjust to the slower pedal timing.

The dealer did also get back to me and said they have some tests that they can run on it for me. So I decided that with 33 hours I will wait til the 50 hour service and have them run the hydro tests then to see what happens.

 

[kapper]

As per our phone conversation. Diagnostic wise look into:

1) Hydro PSI check.
2) Can machine tooling stuck somewhere cause this?
3) Can the wrong type of hydro fluid cause the lag?
4) Can a malfunctioning HST sensitivity dial cause the lag?
5) Can whatever mechanism that protects the engine from stalling, if it is hanging open just a bit cause this problem?
6) Can a lying sensor or weak return spring or stuck solenoid or HST software glitch cause this?

I don't have access and I've never seen how robust Kioti's diagnostic software is, but consider that the tech needs time to work through this problem (especially if on a witch hunt trying to find machine tooling after deciding that all the sensors claim to function but clearly the response is failing to react as expected).

Also Joe, drive another NX HST to get a sense of how they react. I think my tractor reacts relatively quickly. There is a moment of dead space between forward and reverse, but as a tech, I figure that time is there so the transmission doesn't try to do two directions at once and exists when hydraulic pressure to go forward and hydraulic pressure to go backward is equal as demonstrated in the simple green animation below.

I'm guessing that you hit this one on the nose Eric, with your last paragraph. I think this is what was happening, or at least that is what I am hoping. Every time I paused an extra second, I did not notice any lag, or slippage at all. Not sure how John Deere, eliminated this, but whatever, each tractor has it's own inherent properties. So, for the moment, I believe that all is function the way it was designed..... I think...

 

[MinnesotaEric]

Well, after reading over your post yesterday Eric about how you've experienced a similar sensation when you had the anti stall on, I did some self testing today. I've come to the conclusion that the tractor is operating as it is supposed to be... I did 2 things today that convinced me of that. First, after you mentioned that when you had the slipping pedal that you let off the pedal and it kind of re-sets itself. I tried that once when it started slipping and low and behold, it worked. I then figured out that I was most likely trying to operate the hydro TOO quickly from reverse to forward and vice versa. Then, thinking back on when I've had the issues it seemed to always be when I was doing 'active' work, mostly loader work, when I am very quickly moving forward and back.

So, I'm thinking that it is just the design of the Kioit hydro and there is just that pause that I need to wait for a split second before punching it forward. Do I like it? No, not really, but that is probably because I am so used to my John Deere, which literally has ZERO pause, zero slip, none, nata.... So I found that when I pause for just a second and then hit forward, then It does not seem to slip at all.

The second thing I did was play with the calibration. I tried several different ways of calibrating the transmission. What I found out was that I could 'cheat' the pedal travel by calibrating the forward travel to max out at only 3/4 of the way depressed, instead of all the way down. What this did was to compress the power applied to the transmission in a shorter time, which generated noticeably more power in a much shorter time span. This was far more noticeable than that adjustable travel switch they have on the dash. So for users like me, who do a lot of quick to/fro movements, this seemed to help. If anyone has in interest in learned the calibration sequence, I can help

I also learned that if I tried to shorten the pedal even more, like only half way down, that it starts to mess up the motion as you'd get this weird power surge as you let off, plus it was just too much power, too fast. So, I believe that I will simply have to adjust to pausing a moment when hitting the hydro pedals. I did some serious cutting work and grading today, and was very impressed with the power of that thing to be sure. So, I will have to re-learn a little and adjust to the slower pedal timing.

The dealer did also get back to me and said they have some tests that they can run on it for me. So I decided that with 33 hours I will wait til the 50 hour service and have them run the hydro tests then to see what happens.

The differences between the NX HST and the Deere HST would make a good comparison video, as would a how-to calibrate video.

The Rhino blade looks like it is getting put to good use!

That said, software could likely make transitions instantaneous like on a zero turn. What I've noticed with HSTs is that most people like a delay. The first zero turns had no delay and people complained about the sensitivity. So subsequent generations built in a slight delay between operator demand motion, and speed of delivery of that control. Helicopters lag and slow pilot control input demand from the actual response so they fly smother and make them easier to fly.

 

[k0ua]

I can't speak to the new Kioti tractors with the new HST system, BUT on my DK I noticed a "lag" difference when I switched from my Kubota L3400hst to the DK35se. Here is why.

On the Kubota, you as an operator are directly controlling the swash plate in the hydro with your foot. When you switch from reverse to forward you are mechanically tilting the swash plate, and you can do it in a hurry and the direction change can be rather violent. Enough to slide the tires on some surfaces and actually spin them in the opposite direction the tractor is moving on slippery surfaces.

But not so on the Kioti. Your foot is not directly moving the swash plate. You are controlling a "modulator" valve that hydraulically controls the swash plate. Power "steering" for the swash plate if you want to think of it that way. But if you try to force it, and stomp the opposite pedal very rapidly, it does not matter, it changes direction at its own pace and it is never violent. It is rapid enough to work well, in fact very well, and you get used to it in a very short time. It is just not the same design as my smaller/less expensive Kubota.

I know it is not the same thing for your newer tractors, but maybe the philosophy of design is the same idea.

 

[kapper]

The differences between the NX HST and the Deere HST would make a good comparison video, as would a how

OK, I will make a how to calibration video cause its tricky by following the manual, but the dealer gave me a copy of the one they use. I have seriously considered asking if anyone wanted to take a couple of days to volunteer to do a real, and I mean REAL side by side comparison of my Deere and Kioti. I could have them both at my Missouri farm and actually perform pre set tasks, and video the whole thing. That would be really cool! But I'd seriously need a videographer to accomplish it. Just imagine the cool tests we could create!!

Chaining out a 2 ton log, cutting sod, digging gravel, running the 7ft bush hog, driving through the same muddy spots, uphill climbing, claw bucket use (yes, they both have a claw bucket!)

 

[kapper]

I can't speak to the new Kioti tractors with the new HST system, BUT on my DK I noticed a "lag" difference when I switched from my Kubota L3400hst to the DK35se. Here is why.

On the Kubota, you as an operator are directly controlling the swash plate in the hydro with your foot. When you switch from reverse to forward you are mechanically tilting the swash plate, and you can do it in a hurry and the direction change can be rather violent. Enough to slide the tires on some surfaces and actually spin them in the opposite direction the tractor is moving on slippery surfaces.

But not so on the Kioti. Your foot is not directly moving the swash plate. You are controlling a "modulator" valve that hydraulically controls the swash plate. Power "steering" for the swash plate if you want to think of it that way. But if you try to force it, and stomp the opposite pedal very rapidly, it does not matter, it changes direction at its own pace and it is never violent. It is rapid enough to work well, in fact very well, and you get used to it in a very short time. It is just not the same design as my smaller/less expensive Kubota.

I know it is not the same thing for your newer tractors, but maybe the philosophy of design is the same idea.

Well said, I think I've solved the slipping mystery. I believe they intended to remedy this with the adjustment knob, but that does not cure the apparent built in lag time. The problem I have with the built in lag time is this; when I do loader work on hills or cliff edges, I get up close to where I need to dump the load, then when I release the forward pedal the transmission should almost 'lock' and if I gently put my foot on the reverse pedal immediately (at least on the Deere), that reverse 'catch,' if you will, holds me in place to finish dumping and then move backwards.

Not so with the Kioti. I have actually had to use the brake while doing this because of this lag time. So the Kioti will actually start rolling forward until the reverse pedals 'catch up' and hold you in place. I am not a big fan of this, but I will adjust to it for sure.

 

[MinnesotaEric]

Well said, I think I've solved the slipping mystery. I believe they intended to remedy this with the adjustment knob, but that does not cure the apparent built in lag time. The problem I have with the built in lag time is this; when I do loader work on hills or cliff edges, I get up close to where I need to dump the load, then when I release the forward pedal the transmission should almost 'lock' and if I gently put my foot on the reverse pedal immediately (at least on the Deere), that reverse 'catch,' if you will, holds me in place to finish dumping and then move backwards.

Not so with the Kioti. I have actually had to use the brake while doing this because of this lag time. So the Kioti will actually start rolling forward until the reverse pedals 'catch up' and hold you in place. I am not a big fan of this, but I will adjust to it for sure.

The take away question is this: if you had to do it over, would you do it differently?

Video wise, my Minnesota Proving Grounds Facility is way too far away (unless some OEM sponsored us).

 

[k0ua]

Keep in mind on the Kubota HST+ , they let you adjust the lag time from 0 to very smooth transition with a dashboard knob, or the newer models by a menu setting. I used to be able to link to a video that showed that in action, but I believe it is been taken down. But what I remember is with it adjusted all the way fast it slid the tires, on dirt, and all the way the other way it was very slow/soft response. My Kioti is very smooth, but not fast to transition. And cannot be adjusted by the operator.