I too have been following this thread since the beginning. I am still not sure whether this squeal is simply a mountain being made from a mole hill or something of significance.
I understand that the sound is difficult to live with and needs to be corrected. Kioti claims to have done that by changing out a section of metal tubing for flexible tubing. Apparently that has mitigated the noxious sound in at least some if not most cases. That would be the mole hill version. Simply an annoyance which can be corrected with a simple modification. Problem solved.
However, for some owners of squealing tractors, the concern persists that the sound is an indication of something more fundementally wrong with the transmission. Hard to confirm that as none have failed yet but in theory if some abnormal internal wear is occuring failure could come later so that leaves the issue open. That is the mountain version. The flexible hose is a bandaid on a cancerous lesion and will not treat the underlying problem. Problem definitely not fixed.
We've had very little real data to help elucidate the problem. One member with seemingly good engineering skills did some pressure measurements that may or may not have been consistent with abnormal flow/pressure. For some odd reason after an initial flurry of interest he has not followed up. Perhaps subsequent investigation did not confirm initial readings or what were thought to be abnormal readings were within specs. Not sure, I for one am not an engineer and cannot interpret the significance of those findings.
Understandably, a lot of anxiety persists for some owners who do have squealing tractors. Unfortunately, as is typical of Korporate Kioti, the company has not publicly addressed the issue in a clear manner and has repeated the same nonresponsive customer service philosophy they demonstrated a few years ago with the cracked loader issue. That makes matters worse for those who are anxious about the squeal and understandably they remain unhappy. Unfortunately at least some are also sufficiently suspicious of the flexible hose modification repair that they conclude that modification is simply a cover up of some dread internal problem. Sometimes paranoia is justified after all.
My take on all of this to date: We should not blame the victim (those with squealing tractors), even if they are demonstrating an exaggerated concern and are refusing to accept the simple Kioti explanation that the problem really is simply the harmonics in the metal tube and nothing worse. Kioti needs to put out a formal service bulletin on the subject and commit to not only their suggested immediate repair, but also to extend some form of warranty on the transmission for those customers who require the flexible hose modification to control the noise. I recall that with the loader cracking issue, Kioti finally, after far too long a delay, finally made a public statement to owners and dealers and eventually got their act together with a reasonable service bulletin and repair program. Why Kioti cannot act more quickly to acknowledge these things before internet fueled rumors aggrevate the matter is beyond me. They clearly did not learn any corporate troubleshooting lessons from the loader issue. They persist in a hunker down in the fox hole mentality which only makes matters worse for all concerned. Someone at a very high level at Kioti needs a swift and sure kick in the arse to bring them into the 21st century of customer relations and crisis management. If real estate is all about location, location, location, then in this type of service problem the key to successful customer support and public relations is communicate, communicate, communicate. Somehow the big wigs at Kioti just don't seem able to understand that simple axiom.