my spidometer is acting up lately. Sometimes on lower speed 0-50mph it would go up and then it would just drop back down to 0 and it will sit there. However each time when I change gears, as soon as I push the clutch it would jump back up to the right speed that the car is going. And as soon I'm in the next gear it would drop down to 0 again and it will stay there until I engage the clutch again and it will jump to the approiate speed. However once I'm on 5th gear past 60mph it has no problems and I can go as fast as I want with the spidometer giving me accruate readings past 60mph. However on lower gears it acts up, I mean it does work properly the odd times. But I'm just carious as to why it would restore itself for abig each time I punch the clutch in. But once I'm in the next gear the needle will fluatuate and most of the time drop back to zero? Any tips guys?