CessnaPilot

I have a 99 chev express 3500 5.7 gas w/4L80 trans that shifts into 2nd gear as soon as I drive away, usually at about 5mph it hits 2nd (smoothly) It goes thru all gears up and down as it should normally including passing gear on highway. No codes shown on scanner. I replaced shift solenoid to no avail. As I am trying to diagnose the speedo is now reading double the speed, as it wasn't in the beginning. Any help would be appreciated. 1 other thing I noticed is when I shift it into 1 gear and drive from a dead stop it will hit 2nd gear (hard) even though I didn't upshift the lever