erratic speedo on 95 sable

Recently bought a 95 Sable LS wagon. At 60 MPH and above speedometer needle bounces continuosly from 75 to 50, no effects on speed or RPMs. Acts the same when using Cruise control. Hard to tell what my speed is above 60 with it bouncing around. Unknown mileage on car, 3.0 engine. Car runs great and is in very good condition other than the Speedo problem. Any suggestions as to what may be causing it?

I had a 93 wagon with 160k and it did the same thing but only when it was cold eh. i just ignored it, same thing happens in my 95 taurus wagon, but not on my SHOs. does urs do it when its cold or all the time??

Recently bought a 95 Sable LS wagon. At 60 MPH and above speedometer needle bounces continuosly from 75 to 50, no effects on speed or RPMs. Acts the same when using Cruise control. Hard to tell what my speed is above 60 with it bouncing around. Unknown mileage on car, 3.0 engine. Car runs great and is in very good condition other than the Speedo problem. Any suggestions as to what may be causing it?
It does it all the time, cold or hot.

Ahhhh i'm sorry i can't help but i'll tell u some advice i learned, well it did it between 90KPH - 130 KPH (Canadian eh) but i learend that it didn't do it at like 160 and above, (Hit 190KPH hehe, and got 6 feet of air that car was beat really hard still ran too even without a water pump.)