Speedo noise at low speeds (<45)

[Kindred]

I brought this up in the old forum, and I spoke too soon when I said the problem seemed to fix itself. I get noise in the speedo reading inversely proportional to my speed. At around 15, it jumps around about +/-5mph. At 60, if it's still bouncing, it's so quick and minute that I can't tell. What might cause this? I had a new speedo cable fabbed up for my cluster. It's freshly greased, but I haven't greased the back of the cluster or the tranny gear. Would this cause the problem? Since the two ends are attached via a nub (tranny end) and the shape of the tip (cluster end), I figured it wouldn't be an issue.

[FestivaBiker1971]

bad speedo head possibly. common problem in many 80's - early 90's fords and mazdas. the bushings in the head dry out and start to sieze.