Death rattle

hey all, after some advice....I think I'm just about to have my first serious problem since I got the old girl! Got a bad noise coming from the frontish when she warms up, it sounds like there is something wrapped around a prop or a wheel and rubbing badly, iv had a look and there's nowt there, it only starts after iv done about 4 or 5 miles....it doesn't happen when still so iv ruled out the engine....iv greased up the uj's, I realise this is a shot in the dark but maybe some of your experiences can point me in the right direction.
Cheers it's a defender

wheel bearings or a stone in the mud shield?

That might be my first stop, the swivel ball on the front needs replacing....just seen a kit on eBay for £95 is that reasonable...if not can anyone recommend a decent supplier?

PM RobinT he's just bought a swivel ball kit. Which I fitted for him last week.