just coming into my road yesterday as bike slowed i started to feel a reverberating knock coming thru my footpegs. put the bike on stand and while spinning the wheel there was a very faint knock on each rotation, ive pulled the whole wheel apart, cush drive and all. the only thing i found to be wrong was a spring loop which went around the bearing retainer/grease holding thingy. put it back together and no noise, but was this spring crucial?

Sure as eggs are eggs if you lose your grease the bearing will fail. Is it part of the bearing? You don't want bits of steel milling away at your wheel do you.
Have you got a photo ?

na man not the bearing im alright there, they were running nice and smooth fresh grease n all. theres a cover that you pull off to get at the bearings with a "resevior" of grease in it with a coiled bit in it, you probably wouldnt notice it unless you completely took out all the grease.