1991 crew with 454 and 4l80e shifting issue

[duramaxing]

any body had a shifting into overdrive issues on the 4l80e ? i have a 1991 crew v3500 4x4 4l80e when you start out it goes from 1st to 2nd very quick then shifts to drive normal and then wont shift into overdrive. if you try to shift manualy its shifts to 2nd on its own without moveing the shifter then when you shift to drive it tries to go into overdrive for just a moment then goes back to drive. if its going down the road at around 55 in drive and let off the gas its like it goes in nutrel thought it was the transmission needing replaced or rebuilt and i replaced it but its doing the same thing?