Take a look at the current thead on the Kubota Owning & Operating Forum right here on TBN.
Everyone, I have a Kubota M4 (M4D-071HDC12) utility tractor I bought back in 2019. I like the tractor very much, but when the tractor is working for an hour and the transmission oil gets hot, the transmission will start whining when the tractor is stopped. This have been happening six months...
www.tractorbynet.com
In the first message is a video where you can hear the noise plainly. And then several pages of discussion from people who seem to know. So far it doesn't appear to have had any negative effects other than heating the hydraulic fluid....and the rather loud noise, of course.
I've been following along from a interest in mechanics and hydraulics professionally - and apparently others have too.
Kubota is aware and seems to be working hard to fix it at several levels - but so far without success. Several current owners of M4s are weighing in on this & don't seem to be concerned. Other than that, they do like the tractor.
Frankly, if I was buying one I'd want that issue and some sort of resolution agreement written right there into the buying contract. And I might just include a time limit. But that's just me and the way I do business.
As it sits this week, the noise is something they expect Kubota to take care of completely.
We'll have to see.....It wouldn't stop me from getting serious about what looks like otherwise a good tractor.
just sayin'
rScotty