If you "lube" the cable, you will soon have lube on your toes as the action of the spinning cable will draw the fluid up to the back of the speedometer where it will drip out onto your foot... and everything inbetween the speedometer and your foot. I've found the best method is to remove the cable completely from the sleeve and soak it in kerosene for a couple hours. Take it out, wipe it down clean with a rag, and reinstall.

My experience with a bouncy speedo needle has led me more to believe it is the breakdown of lubricant inside the speedometer itself, where the central shaft meets the magnet. Usually not the speedo cable. But it's much easier to remove the cable and check that first than to go out hunting a new gauge. <img src="/forums/images/graemlins/wink.gif" alt="" />