When I turn off my car there is a grinding sound

When I drive straight, I hear a low amplitude noise resembling wobbling or humming. It matches the frequency of the wheels and can be felt as vibrations and noise in the car. Especially in the rear. It can be felt and heard at all speeds right from 10 mph when it becomes noticeable to all the way up. At higher speeds, because of the high frequency vibration, there are also harmonics that are set up like a low humming. I can sometimes even feel the wheel wobbling a bit. Im confused with the noise dominating in the rear yet steering wheel feeling it.

When ever I shift into 1st at a slow roll it grinds as well as everytime I shift into second and sometimes third but most problems come for 2nd gear. I can push the clutch in and insted of pulling straight down I pull down half circle then down into second and it lets it go in nicer at a slow roll. But if I hitting on hit gettig up to highway speed it will grind bad in second. And if my car sits over night it sticks a bit in 1st.

Can this cylinder be adjusted or does it have to be replaced. and how much work is it to replace?

Yea it is threaded. How do I adjust it? My Reservoir last checked was full and I checked it little while ago. Cause i've been having this problem for a little while now.