I fired up my Massey 1650 this spring, and noticed that when starting out in high there is a brief higher pitched whining noise (not grinding) when starting from a stop and accelerating in forward or reverse. Doesn't last long, maybe a quick second or two. As far as I remember it wasn't doing it last year when I parked it. The noise doesn't happen when I'm in low.
As a side note, the transmission tends to fall out of gear when in high if it gets a little bumpy; stopping and putting it back in gear is no problem, but is there an easy remedy for this, aside from a bungee cord.
I started by swapping the hydro fluid and filter, but the noise is still there. The previous owner had told me the trans was rebuilt. Any ideas on what could be the cause, or if it's even anything to be concerned about?