Speedometer problem.
 

I just replaced my speedo cable 4 days ago because the old one was causing the speedo to"jump" and making a strange noise.

Tonight, I noticed that the speedo was again starting to jump a little.
Is there some mechanism in the wheel that needs to be packed? Or are there gears or something in the wheels that can wear out and need to be replaced or is my speedo going bad?

OR?