speedometer bounces?

NO, do not use grease. You need to use a dry lubricant such as graphite. Using grease will only make the problem return in a short time, as grease will wear off quickly. Remove the cable from the car, remove the core, clean the casing our thoroughly with brake cleaner until it runs out CLEAN. Clean the core off until it is very clean, let everything dry then apply a liberal amount of graphite into the casing and on the core and reassemble. Problem solved.