I have recently purchased my truck. It did not shift when I got it, I checked under the hood. I found a couple vacuum lines loose. It started shifting like mad. I drove it a couple days after that. It shifted OK then. Later that evening the tach dropped, the speedometer dropped(quit). THE CHECK GAUGES LIGHT CAME ON. I LET IT SIT UP A COUPLE OF DAYS. THE CHECK ENGINE LIGHT WENT OFF. THE TACH AND SPEEDOMETER STARTED WORKING. BUT STILL NO SHIFT OUT. I HAVE CHANGED THE SHIFT SENSOR ON TAIL OF THE TRANSMISSION, ALL FUSES R GOOD. I AM LOST. HEEEEEEELP!