Case 385 whining sound with pto off

[Monkey man]

Hello long time lurker, I recently got a 4wd case/ih 385 tractor, it looks like it's had a rough life but seemed to run and drive fine, iv used it to dragging logs and some front end loader work, I recently got a brush hog for it, I used brush hog today for about an hour, I unhooked bush hog now I notice with pto off it makes a whining noise kinda under seat/feet area but if I engage pto it goes away, fluid is topped off, I'm kinda stumped and ideas or suggestions? Thanks in advance