GMC TRUCK INSTRUMENT CLUSTER GAUGES SPEEDOMETER

Transmission Problem 2009 Gmc Truck V8 Two Wheel Drive Automatic Hi, I Just Purchased A 2009 Gmc Truck (nice Rig, Dont Get Me Wrong...

My Speedometer Started Jumping Up And Down. It Would Read Correctly At 60 Mph And Then Start Jumping Between 20 And 45 Mph Then It Would...