Going in reverse

Does anyone know why when I try to gone quickly in reverse I hear a grinding noise. So I have to go pretty slow and never let my foot off the clutch. Does this mean that the gears for reverse have been ground down. And is this something that is easily fixible or do I have to change out the whole transmission?

Reverse isn't synchronized, if the car is moving at all, you'll get a bit of grinding. This is true of most cars.

You can also minimize the mismatch by putting the car into another gear first before shifting into reverse (4th works well and is next to reverse).