Kubota M4 Utility Tractor Transmission Whine

[Bavarian]

That problem is weird, to say the least.
A bad relief valve can cause excessive heat. But at the same time, there should be a noticeable loss of performance in the hydraulic system.
Since the system itself is open center, there shouldn't be enough pressure to even push a damaged relief valve open.

I feel your pain, guys. The M4 is a significant sized tractor already. I did look at one a good year ago. I did like the layout and specially the sunroof option for loader work. Now I'm glad I didn't pull the trigger and kept the green tractor.

 

[Jigawatts]

Had mine running for a little over an hour doing chores this evening and didn’t use the remotes so figured I’d see how mine felt. Does yours have the same block on top?
View attachment 745259
I’m pretty sure that’s what allows the flow to transit from one side down the other. It wasn’t too hot to touch but was unpleasantly warm. The top valve wasn’t hot but was warmer than the bottom which felt only slightly warmer than anything else back there. I think that’s just normal operation. I know when I use the remotes and need to swap implements/hoses they are warm enough I wear gloves for more than just protection against hydro pressure leaks. I didn’t feel anything that seemed to be moving/vibrating but it’s on a running tractor so not the easiest thing to feel for.

Yes same block on top. Just three valves, which should not change anything unless there is something up with the valve that the dealer installed? I haven’t put an infrared thermometer on it yet when hot, but am gonna get one to do so next trip out. I have multiple tractors and the trans fluid temp has never felt this hot on the valve body, trans casing, pump, hoses, etc. in any of the others. It is HOT….I agree with the logic of fluid passing through and the feeling of what I am calling a vibration for lack of a better way to explain fluid passing through or reverberations?? I just don’t get the noise and the temperatures. I truly appreciate you taking the time and value your input!
The other protruding item I’m wondering about in the pic below is located just in front of the remote stack? I am guessing it is a relief valve of some kind? Maybe? Not sure but also located in that vicinity of the strong noise and feeling? Like you say hard to pinpoint noise with running tractor..

 

[sea2summit]

View attachment 745412Yes same block on top. Just three valves, which should not change anything unless there is something up with the valve that the dealer installed? I haven’t put an infrared thermometer on it yet when hot, but am gonna get one to do so next trip out. I have multiple tractors and the trans fluid temp has never felt this hot on the valve body, trans casing, pump, hoses, etc. in any of the others. It is HOT….I agree with the logic of fluid passing through and the feeling of what I am calling a vibration for lack of a better way to explain fluid passing through or reverberations?? I just don’t get the noise and the temperatures. I truly appreciate you taking the time and value your input!
The other protruding item I’m wondering about in the pic below is located just in front of the remote stack? I am guessing it is a relief valve of some kind? Maybe? Not sure but also located in that vicinity of the strong noise and feeling? Like you say hard to pinpoint noise with running tractor..View attachment 745414

Shoot, we’re all in this together. My time is our time….I just have a book
According to the book that’s the safety valve. When checking the pressure at the remotes you check the relief valve pressure first then the safety valve.

It just looks like a relief valve in the schematic? Item 17 is the safety valve, remotes are item 10, lowering speed adjusting valve item 16. It’s higher pressure than the primary relief valve, maybe it’s there for shock loads on the remotes or to smooth the shock loads?

ETA I didn’t get it hot yesterday I was just doing animal chores with it. Next week I cut hay and I’ll have both the Max and M4 going several hours in the heat so I’ll try to remember to take some temp readings between them to see if there’s big differences at the remotes.

 

[JP_Austin]

I seriously doubt that it’s related to the remotes in the rear. My noise is right side and closer to the front. In the manual the only relief up in that area is for the power steering.

As for why when fluid is hot… my theory on that is the viscosity is significantly lower. Any poorly seated relief valve that may leak a bit would be subjected to a lot more fluid flow. If the pump has a harmonic (and it does as I can raise and lower engine RPM to modulate the noise) I’m suspecting it’s an interaction with the pump and the system of hard lines, reliefs, and the cooler up front.

I’m reminded of odd engineering hacks that deal with unpleasant harmonic reverberations. Automotive engineers have used all kinds of masses cantilevered off mounts or in some cases they add rubber encased weights that seemingly do nothing to us mere mortals. However if there is a several pound weight hanging off an otherwise pristine engine bay you can guarantee that someone ran across a harmonic issue at some point along testing.
I’m hoping it’s something like that but still suspect it’s simpler. I state that since so many of us are reporting near similar circumstances and resultant noise.

 

[jonsstihl]

I think the safety valve is for the three point lift. Mine is set around 5000 psi and it is for shock loads. example roading a heavy 3 point mounted implement.

funny you should mention weights hanging off something. the grand L series has weights hanging off the cab mounts.

 

[sea2summit]

Mowed with mine last night to check that remote heat, forgot my temp gun but as soon as I touched it I took my hand off. She was really hot. But as mentioned I'm certain that's normal operation, it's just a result of the fluid temp being near the surface.

I also had no whine yesterday, I'm trying to remember if I've noticed the whine when it was really working or if it has only been when it's cooler. The trouble shooting continues.

 

[Bush Whacker]

Mowed with mine last night to check that remote heat, forgot my temp gun but as soon as I touched it I took my hand off. She was really hot. But as mentioned I'm certain that's normal operation, it's just a result of the fluid temp being near the surface.

I also had no whine yesterday, I'm trying to remember if I've noticed the whine when it was really working or if it has only been when it's cooler. The trouble shooting continues.

Sea2Summit, questions for you if you don't mind, where you in 4x4 ? do you have a loader? How many hours do you have?

Asking because I am the second owner. I got the dealer to add a loader with third function and a third remote on the back. My remotes also gets really hot and they seem to humming. The Dealer confirmed with original owner that whining never existed for him so I am now wondering if it this is all related in adding a loader or a third remote valve. Mine as less then 200 hours.

 

[sea2summit]

Sea2Summit, questions for you if you don't mind, where you in 4x4 ? do you have a loader? How many hours do you have?

Asking because I am the second owner. I got the dealer to add a loader with third function and a third remote on the back. My remotes also gets really hot and they seem to humming. The Dealer confirmed with original owner that whining never existed for him so I am now wondering if it this is all related in adding a loader or a third remote valve. Mine as less then 200 hours.

Yes 4x4 and loader, just over 230 hrs now.

Wasn't able to run my MX bud I did run an older deer as a second tractor and the remote felt just as hot, not surprising to me.

 

[Bush Whacker]

Yes 4x4 and loader, just over 230 hrs now.

Wasn't able to run my MX bud I did run an older deer as a second tractor and the remote felt just as hot, not surprising to me.

Thanks for the info. Nice to compare apples with apples. I just got off the phone with Kubota Canada. They told me to call the dealer again for an update as they have open tickets in their system. Dealers call it Kubota forums.

So I take it your tractor doesn't have the same symptoms reported in the videos posted in this chat?

 

[Codybrown]

Have my M4D for three days now has 20 hours just using a batwing mower and started having similar issues but I am losing steering as well has anybody checked the fluid level? I am sure a lot of people have but I had a line leaking two hours after I got the brand new unit pulled it back to the truck checked the fluid and I was halfway in the operating range and now after the noise has occurred it is extremely overfull and looks like it is about to come out the top of the dipstick hole also the tractor does not have a loader whatsoever strictly used for large acreage mowing