speedo sender trouble?

OK, my speedo was fluctuating 5mph up and down from the actual speed yesterday. Today it just pegged.... I know I was getting a bit oil through it. Could that be it? Wire looks intact, nothing else seems wrong. Any ideas? It's still got moments that it shows appropriate speed and then it goes on a crazy dance all over the range and even past it.

I had the same problem, pulled the speedo gear from the tail of the transfer case, cleaned it, realigned it and it works fine now.

The speedo gear is plastic, but has a electical sensor that sits on top of that. So it may be the plastic gear moved out of the correct index, or more likely you have oil in the electical part causing the problem.

Easy to work on, btw.