Hey all. I have a 2019 Silverado HD with the 6.6l diesel and Allison transmission. When I have my 5th wheel trailer attached and am parked on an incline, when I put the truck into gear, the transmission makes a loud clang. It sounds like it's gonna fall out. Doesn't matter whether I'm facing downhill or uphill. Never happens on level ground and never happens without the trailer attached.

Does this happen to anyone else, and if so is there something I can do to prevent this. Thanks for your input.

 

Could just be that there is pressure on the parking band when you are parked on a hill and when you shift out of park it takes more force to disengage from the load on it. Could be something else but I'm sure others will reply soon