Speedometer Problems

My girlfriend just got a 2003 Cavalier with 44,000 miles on it at the beginning of December. It's been great so far but the speedometer started going bonkers. It would work fine, then start getting really choppy after about 10 minutes on the road. The problem was getting progressivly worse, and now we just got back from a road trip in it was getting stuck at one speed, then it will increase to another and get stuck again. The needle would litterally be stuck at 50 mph, then we'd park, turn of the engine, start it again and it would say 50 until we started rolling, then it would increase to say, 100, then turn it off, and do the whole thing over again.

By the way, the speedo's in these don't have pins to stop them past 110. I had the needle wrapped all the way around to almost zero again by the time we got home. :ylsuper:

Any ideas? All of the other guages work perfectly. Could it simply be a screwed up gear in the speedo? (do they even work off of gears??) Or is it just a bad cable?

FYI - If you've never driven a 7 hour trip trying to judge your speed using only your tachometer (while trying to "test" the upper edge of the speed limit, of course), it's interesting.

try speed sensor.

with 44k? isnt that out of warranty?