would this be a bad speedo or a bad speedo cable?

[ineeda5.0]

I bought a cluster off ebay because my fuel gauge and speedo gauge were not working properly. So this bought cluster has a very bouncy speedo and it makes a loud noise coming from the speedo gauge. kinda like a loud annoying whinning. My mechanic says its the speedo gauge itself because we already changed the speedo cable... what do you guys think?

 

[srjs28]

i had the same thing on a 95 escort. it was the speedo gauge itself. i too replaced the cable and it did not fix the problem.

 

[BlackGT89]

There's a magnet that rotates inside a cup at the speedo. I'm not sure what all can go wrong there but it probably involves age, vibration and general deterioration. This website has a pretty good explaination on how it all works: How does a speedometer work? - Explain that Stuff!