DK40SE Squeal When Moving in Reverse.

[Coyote machine]

Caver,
Even if it were to squeal on the lot, I wouldn't necessarily walk away if the price is right. And, you have a two year warranty covering things like the squeal issue, which Kioti is continuing to seek solutions to. I've got 300+ hours on my DK-40se/hst since last Oct when I bought it. The noise showed up at 10 hours and it has not caused any adverse effect that I'm aware of, other than the obvious noise annoyance. The DK-40 is a stellar tractor, and I state that having owned a DK-35se/hst for about the same hours and traded it for the 40 to have a better FEL capacity and other features the 35 could not provide. I was joking with my wife today about trading it for a bigger Kioti, so I can do some real damage. I told her later I was kidding- so she wouldn't worry.
If it were me I'd want to see evidence of the 50 hour and other service that was required up to the current hours on the tractor.
Good luck, post back results, and BTW, you're welcome for the update info- glad it was of use.

 

[caver]

Coyote

The deal breaker will be more along the lines of what he gives me on trade in.
He's a well known Kioti dealer and a good dude to do business with from my past experience.

My LB1914 TLB has less than 100 hours on it but out of warranty. Any idea what a dealer would offer? hahah:laughing:

 

[Mike476]

Very interesting thread that I've been monitoring for some time now. I don't own a tractor with HST and I don't have any knowledge on their engineering other than what I've read on this forum but I do have some experience with hydraulics.

Not sure if the relief valve CM mentions Kioti is considering for future model years is thermal or pressure but I can tell you that engineers try to avoid excessive heat in a hyd system whenever possible. Nothing earth shattering there I know, on some aircraft we route hyd return lines through fuel tanks to cool the fluid on return to the resevoirs, works very well.

The other thing we try to avoid are surges, hyd systems operating numerous control surfaces, landing gear etc are of course engineered so that systems operations, whether independently or concurrently, do not exceed the volume and pressure capabilities of that system. To do this there are several pressure regulators, flow restrictors, metering valves and check valves incorporated into each system. Again, nothing earth shattering there either.

What might be of interest is that on most older aircrat I've worked on whose systems are configured as stated above, there is almost always a surge suppressor in the return system just prior to the resevoirs. For the most part they are nothing more than a series of plumbing loops mounted in such a way to assist in absorbing shock loads when multiple systems are in operation simultaneously. What has that got to do with the HST problem?

The reason we don't want shock loads or harmonics in a hyd system is that fluids used are chosen for compressibility characteristics. Heat dissipation, surge suppression and harmonics are left to engineering.
Harmonics in those same fluids are felt throughout the system, and in aircraft whose autopilot sustems incorporate flight control load sensors etc, harmonics are not a good thing. Are HSTs as complicated in their engineering, probably not, but I would be a hard sell that over time they would not adversely affect the HSTs operation, but that is just my opinion.

All that to say that sometimes harmonics in hyd systems can be widdled down to something as simple as how plumbing is mounted, how increased temps in the fluid expand the plumbing that when cool don't exhibit any harmonic resonance. I would think if Kioti believes this to be the case they are likely more concerned with possible "cause and affect" issues down the road where the harmonics may actually cause premature component wear down the road if left unresolved.

Just my two cents, I'll continue to monitor this forum to see what results those of you actively pursuing a resolution get from Kioti, stay persistent and hats off to you for persevering!

 

[Coyote machine]

Fortunately for most of us our tractors are earth bound and are not likely to fall out of the sky if something serious goes wrong. A harmonic imbalance in something like a flywheel can and would likely do some damage to the system it is connected to eventually. A fluid harmonic imbalance caused by flow or pressure or whatever specific set of circumstances might also render damage but probably over a greater amount of time and not necessarily be catastrophic in nature.
Fluid hydraulics and their dynamics make for difficult to solve problems that can be elusive in nature. Piping, material used for such, and fluid viscosity and temperature are all factors, nothing new here, however, how these factors influence each other and the outcomes of the influence is what makes quick and easy solutions to things like noise generated and its consequences beyond just the annoyance of the noise as a symptom more difficult to resolve than something like a failed bearing as a result of lack of grease, for but one example.
I'm hoping that the current solution provided by Kioti/Daedong is sufficient to last the life of the HST transmissions currently inflicted with the symptomatic squeal. Time will tell, as with most things.

 

[quiturcrying]

Apparently all these engineers have no clue about harmonic noise and natrually assume it is more serious. I can and will tell you it is strictly harmonic noise and there is no damage to the HST unit! The rubber hose simply allows for a less abrupt flow and the rubber asorbs the harmonic noise. As for the drawing.... get a life! It is crude but effective.

 

[caver]

My dealer has not come across the problem but said he had heard about through internet discussions.
Just brought home a lightly used Dk40SE HST with box blade and Horst 3700 lb pallet forks. Still trying to get used to the hydrostat and the throttle lever seems backwards from my LB1914. I hope to have it over at my property in the next few weeks.

 

[Coyote machine]

Apparently all these engineers have no clue about harmonic noise and natrually assume it is more serious. I can and will tell you it is strictly harmonic noise and there is no damage to the HST unit! The rubber hose simply allows for a less abrupt flow and the rubber asorbs the harmonic noise. As for the drawing.... get a life! It is crude but effective.

So I take it you're speaking from a place of more education then a M.E or E.E.? Somehow I highly doubt it. You throw out wild statements about engineers not knowing anything and yet you also want to tell us what is happening inside an HST transmission without backing it up with anything but your couple of poorly written sentences?!:confused2: You list no tractor or anything else of real identification as to who you are in your profile, and your general tone is condescending and basically rude- but hey, with a name like quityrcrying why doesn't that surprise me? I also take it you're referring to the original drawing supplied by Kioti to various Kioti tractor owners experiencing the problem detailed on the preceding bunch of pages prior to your post. No one is even speaking of it but you, so you're welcome to take your own advice and get yourself a life.
Why are you even posting about this thread unless you have an HST transmission affected by the issue?

 

[IslandTractor]

Coyote, don't bother squabbling with Quiturcrying. I note that he joined just last month and from the four posts made so far clearly establish: 1) not a newbie, 2) not inexperienced with details of Kioti products including Mechron, 3) technically quite sophisticated on diesel engines (read the lubricity study he linked). I would hazard a guess and say he is either an experienced dealer in disguise or a Kioti factory rep. In either case, clearly he is operating incognito and will continue to hide his identity. I think it would be helpful to have someone like this participate under a pseudonym as the false identity permits him to be more honest and less diplomatic (which is a good thing).

Happy New Year Quiturcrying and welcome to TBN (in this guise). I hope you are what I think you are and that you continue to participate.

 

[Coyote machine]

Island, I appreciate the advice/warning, and I have the same sense about the guise/cloaking of the aforementioned participant. What I don't understand is what purpose does it serve for a dealer, for instance, to try to pull off these thinly and poorly contrived cons? Or, for a manufacturer's rep, for that matter. Yes, I saw the link to a study too before I posted; I just get annoyed by people playing stupid games when some of us are actually trying to get things done. You?

 

[IslandTractor]

Island, I appreciate the advice/warning, and I have the same sense about the guise/cloaking of the aforementioned participant. What I don't understand is what purpose does it serve for a dealer, for instance, to try to pull off these thinly and poorly contrived cons? Or, for a manufacturer's rep, for that matter. Yes, I saw the link to a study too before I posted; I just get annoyed by people playing stupid games when some of us are actually trying to get things done. You?

I don't see it as a con at all. Just an individual being more honest than they could if they were representing their dealership or company. "Off the record" will often get you a more honest appraisal than something that the speaker needs to explain to his boss.

 

[Coyote machine]

I don't see it as a con at all. Just an individual being more honest than they could if they were representing their dealership or company. "Off the record" will often get you a more honest appraisal than something that the speaker needs to explain to his boss.

OK, Interesting concept- hadn't considered that possibility.
Thanks for the heads up.

 

[RJJR]

Apparently all these engineers have no clue about harmonic noise and natrually assume it is more serious. I can and will tell you it is strictly harmonic noise and there is no damage to the HST unit! The rubber hose simply allows for a less abrupt flow and the rubber asorbs the harmonic noise. As for the drawing.... get a life! It is crude but effective.

If it were as obviously simple as you state then I believe Kitoi would ? should? put out a service bullentin to address the matter and put it to rest. Period. More likely they aren't sure what's going on which is why they haven't. To quote a project managment principle they have a "known, unknown, amount of risk" to mitigate and they aren't sure how to do that at this point. Credibility is a hard thing to maintain and even harder to regain. Putting your head in the sand doesn't ususally help either. Love my tractor but that doesn't change my assessment of the situation.


RJ

 

[quiturcrying]

I understand your position on the HST squeal. Information is forth coming to the dealer network and they know who to ask. Bottom line, It is all harmonic noise and aggrivating, not catastrophic.

 

[RJJR]

I look forward to that.
Thanks
RJ

 

[Coyote machine]

I can confirm that there is a paper trail from Kioti, but can say no more about it, than I've seen it and it does address the issue directly and officially. We're talking internal documents, NOT for public distribution. It is part of why I stated earlier that anyone who has the squeal issue or thinks they might be experiencing it should contact their selling dealer and discuss it with them. If they are unfamiliar with the problem, or Kioti's current official solution then they know what to do - contact headquarters.
So PLEASE be patient, the issue IS being addressed and Kioti is on top of the situation.

 

[seacap04]

Anyone with a squealing DK40 due for a hst filter change? If they are, how about grabbing an oil sample from it and have it checked out. This may ease concerns that the upcoming fix just treats the symptom and not the problem. You can also cut the filter open and use a bright light or magnet to check for metal filings.

 

[Coyote machine]

Anyone with a squealing DK40 due for a hst filter change? If they are, how about grabbing an oil sample from it and have it checked out. This may ease concerns that the upcoming fix just treats the symptom and not the problem. You can also cut the filter open and use a bright light or magnet to check for metal filings.

A good idea. I'm planning to do an 'early' 400hr service at something over 300+hrs., once my selling dealer receives the parts to do the rubber hose/fitting changeover, which is the official remedy for the squeal noise. I could save some oil from the filter to have analyzed, I suppose.

 

[seacap04]

It was just a thought I wish I had a few months ago when I started following this thread. For around $10 you may sleep better at night. I just changed the trans fluid and filter in my DK45, The drain plug has such a powerful magnet in it that it is a little difficult to put back in. I was very impressed with the design, The hydraulic filter has the same in the stem on the filter housing. I had a few filings on drain plug, but I do not know how long this fluid has been in there. The filter is the next best place to check and I plan to cut the HST open in the next day or two.

 

[Mike476]

Apparently all these engineers have no clue about harmonic noise and natrually assume it is more serious. I can and will tell you it is strictly harmonic noise and there is no damage to the HST unit! The rubber hose simply allows for a less abrupt flow and the rubber asorbs the harmonic noise. As for the drawing.... get a life! It is crude but effective.

First let me say that my interest in this post is that I have narrowed down my next tractor to a Kioti or MF, and that the harmonic issue some are experiencing will only be an issue for me if Kioti mismanages the situation. All manufacturers have had issues with their product, Kitoti is no different. Like autos, we the consumer fear recalls less and less and are now more concerned with how they are handled by manufacturers and dealers.

Not sure who you were referring to but speaking for myself, what I do know after 30+ years of working on hyd systems, vibrations analysis and health usage monitoring systems is that harmonics are an issue.

If Kioti has collected data that supports your claim that there is no damage to the HST, which would of course require extensive testing to confirm no issue exists over the expected life of the tractor, then I'm sure we'd be interested to read it. Otherwise, from my perspective, the comment is not only unfounded but when coupled with the fact that some seem to know details that others may not, being forthright and full disclosure on these issues are business practices proven to work. Todays consumers are much more informed, one only needs to do a little research into harmonics in hyd systems to discover a lot of money and engineering goes into mitigating their affect.

As others have stated, a bulletin stating something along the lines that "Kioti appreciates the concerns of current owners and those looking to buy our products, rest assured Kioti is investigating potential cause factors to ensure our product maintains its superior reputation and that our customers continue to enjoy what we at Kioti believe to be the best product on the market today". No personal emails to those unwilling to ignore the issue, FULL DISCLOSURE, PERIOD!

 

[somguyss]

I really wish that everyone would understand that the issue with the HST squeeling is totally a HARMONIS ISSUE only, I want to ask everyone who has had this issue for a legthy period of time and would like a honest answer.

1. Has your HST failed due to this noise?
2. Has there been any performance issues?
3. Other than the harmonic noise are you satisfied with your tractor (leave dealer expierence out)