CHUNKYS RS

hi i need some advise as i took the gearbox out of my frst to replace the seals and gaskets .all was going fine removed the casing and left the gears in the other half so as not to disturb them,replaced gaskets and put it all back together refitted the box but now it is very notchy in netrual when going side to side and seems difficult to get into gear sometimes
i have not driven the car as i don't want to do any damage
any help guys i am really stuck