i didnt realise megans had diffs?? if by diff you mean the diff built into the gearbox on the front drive chain then there will be two hex/torx drive plugs one will be a higher point to the other usually accessed from under the vehicle undo the top one and fill with correct fluid that is in manufacturers spec book until the fluid just dribbles out of the top hole replace plug torque it to reccomended setting job done
GARY=)
July 2010