Gearbox helllloooooo!

Hi all recently bought a second hand box . I took my old one out slapped the other on in.

Now i cant get the car to sit in any gear. I have reset the linkages 3 times. 

I can pull the gear into 2 and 4th but when i let the clutch out it squeals and groans. It won't engage.

I have unhooked the linkages and tried to manually move the selector and still won't sit in a gear

Have i missed something or is new box goosed,??

Thanks