Speedometer Problem

I am borrowing a 1991 Cutlass Ciera 3.3L V-6 until my car is fixed. My problem is the speedometer jumps around all over. Is there anyway I could fix this without buying anything?

Ya U Can Pull The Cable Out Of The Back Of Dash Remove Inner Cable And Lubricate With Wd-40

Thanks, I will try that tomorrow. The jumping speedometer drives me nuts, and besides I don't want a ticket.