I've just looked at my G3L and it has six bolts holding the drum/sprocket on with a unused hole between each bolt (12 holes in all). On the offside there are only three large hole thus you have to spanner the bolts tight ( there's lock nuts on the other side) as you can't use a socket/ box spanner on three of them.
I've no idea of this "correct" but that's how it is on my bike.
Richard