Dottie has not long ago had her major service but leading up to it, I had heard an intermittent metallic 'clunking' sound which sped up as we did. It sounds like something turning and making the noise. I am up for a new speedo cable but it sounds far worse than that. After a few minutes it went away. Mechanic couldn't find the source. The first time I heard it I did crawl under to check to see if anything was dragging/hanging off! But the noise is back. Only this time it's louder. When I put the clutch in, it disappears. Let clutch out, it's back. It appears to be coming from left hand side/front. Any advice?! By the way she's a '74 T2 Bay.