2006 chev impala automatic trans will not auto shift
recently I parked my impala for 2-3 months and jus reinsured it. 10,000 km's ago I changed the transmission it was ok only bit of pause from reverse to drive and if wasnt careful it would make loud clunk. Thats not the problem though now that its on the road again the transmission will only shift manually 1st-2nd-3rd-4th and so on. I took it out on the highway to see if it would loosen up something but now I have no 1st gear. Is the trans on its way out or can I run it till something loosens up or gives....someone help me