Volkswagen: 01 VW Jetta Speedo fluctuating, vw jetta, speed sensor

Question
Hi! I have a 2001 VW Jetta GLS automatic. As of yesterday I noticed that the speedometer constantly fluctuates, the tach is also a little jumpy. I know it's not giving a correct reading. Also while driving on the highway we accelerated to 120 km/h and continued to accelerate however the speedometer was stuck on 120km/h.
Note: The transmission was rebuilt 1.5 years ago.
What could be the problem?
Your help is appreciated.
-Farah
fluctuating

Answer
from what you are describing, three things come to mind, either the speedo has died/or is dying,... the speed sensor is on its way out, or the transmission is having a problem.  honestly, I would take it in to the shop and have them test the speed sensor first.  this is the cheapest fix first of off, secondly the next area to look at is the speedometer.  VW offers remanufactured speedometers now, so the prices have dropped a bit.
Good luck and let me know what you find,
shad