My gearbox sounds like a bag of nails at the moment. So i had a little look at it, and it appears to be leaking fluid. I followed the leak back and it looks like it all came out the top where the gear stick attaches to it. Does anyone know why this might of happened?
I was told it had a new gear box not to long ago, but not sure if it was the right one cause it looks like its had piece cut off of it to make it fit

Also how do i refill the gear box and what is the best stuff to use?