Why does my speedometer keep bouncing back and forth?
Why does my speedometer keep bouncing back and forth? The cable spins and the faster it spins the more it can fluctuate. The cable spins the gear for the miles and a magnet for the speed. There is a spring on the back (inside) that puts tension on the the spinning magnet to keep the speed steady. Where is the clock spring on a speedometer? The "clock spring" on the front speed cup ensures that the speed cup's resting position is at the "zero index" point on the speedometer's face plate . . . no more, no less, although it's...