super bully axlles

[darknight]

hi guys, i have some super bullys, now they are the first ones i have had so bear with me if this is a silly question.
they have metal hexes on to fit the esavage wheels, but what i want to know is they seem to have a lot of "slack" in them.
with or without the wheels on the i assume its just the hexes move in and out a fair bit, obviously with the big wheels on this is amplified.
also the take up from the gearbox has quite a large slack area on both front and back (both the same)
all im asking is this normal for them,
cheers for your help