Just using this as a reminder to you use chock blocks. You never know when something isn't gonna work. I picked up a parts M1008 a couple weeks ago. Been tearing it apart, but needed to move it out of the way for a bit. Hooked the tow bar up to the back of it and dragged it up to the upper area. Everything was good, placed it in park and unhooked the tow bar. Next thing I know the parts truck is rolling away with the parking pawl clicking inside the transmission. Thankfully the doors were already removed so I was able to jump in and turn it so it would just stop in the field. Thankfully it wasn't a bad day, but a chock block would have prevented the risk. And yeah I knew better but figured hey it's just a pickup, park is enough.