For a while now my truck has been really difficult to get out of park. Once its in gear it would run fine but here recently it has been acting funny. Sometimes it runs fine but then it shows that its in tow haul then overdrive off then back to normal. the tow haul button does nothing now. it seems to not shift into overdrive for a while then it will just start shifting rights. wondering what may be the problem. I have a ATS copilot and the tranny is ATS built but the copilot hasnt worked right for a while now.

 

I drove it to work this morning and it wasn't shifting into overdrive. It usually shifts at around 50 MPH. Once i got into town and put it in park then back into gear it worked fine until i was driving home and hit a good size bump in the road and it downshifted and stayed there..