Buick Repair Questions? Ask a Mechanic for Answers ASAP
It needs a passenger temp door actuator. They will be fine hours to replace. I can do them in about an hour but I have done a lot and have skinny arms. It's worth asking around at some outside repair shops to see if you can get a deal. The standard procedure though is to pull the dash.
Check you fluid condition but overall it sometimes will get a bit more jerk or off reverse due to line pressure having been up while in reverse. Let me know how the fluid looks.