Was trying to work on my 06 suburban. Replaced all transmission fluid, gear oil in the differentiator replaced shift solenoid, torque converter pressure, solenoid. When I put the car in reverse, it makes a loud clunking sound. It sounds like almost somethings spinning, and not catching. I also recognize that when I take the parking brake off in my foot on the break, the car moves while in park. Please help I don’t like to play guessing games too much but that’s what I’ve been doing and I’m starting to run out of money. Any knowledge would help and I’ve looked at many YouTube videos and I just don’t know where to start after that thanks.

 

Welcome to the forum.

Not sure if current transmissions do it this way but older transmissions would have a parking pawl that engaged when you put it in Park preventing the vehicle from moving because it basically locked up the drive train.

 

How was it working or what was wrong before you did all the work?
BTW welcome to the forum Benny B!