If your speedometer is jumpy, if yours is the old type they used to have on most cars, you can probably replace it for $15-$20. You can try to lube it, but you'd need a very thin grease so it gets all the way down. Might be best to use Liquid Wrench Silicone Spray (not nut and bolt remover), as its sort of like an oil, very thin, but better.