Just a quick question....I've got a ratlle coming from a heatshield on my centre box (i think its the centre box) at about 3000rpm, which is really getting on my tits now

Its one of those horrible little 'washers' with splits cut into it that grips a 'pin' that has come loose...is it ok to just take that heatshield off? If not anyone know where i can get a new washer or have any suggestions as to how i can secure it and stop the rattle?
any help appreciated
