Hehehe, I've also gotten a similar noise that mostly comes on when I use reverse but at times with no HST pressure. If I push on the clutch enough to take up the freeplay then the noise disappears. It's quite loud and sounds like a pulsing screech.
Comes and goes. I imagine it being a throwout bearing being scraped by the fingers on the pressure plate.
I adjusted the clutch to spec, really just verified it, and no change in the screech. Everything works fine.
HB...
I was playing with the tractor this weekend and I think you may be on to something. I suspect it's like you said: "throwout bearing being scraped by the fingers on the pressure plate." Or, it could be the throwout bearing going bad. You'd hardly think it would go out so soon, I rarely use the clutch. It did quite down after I engaged the clutch down (some).
Thanks again. We'll be keeping an ear open if it gets worse.