When shifting the engine/transmission jumps but not all the time

Good morning.

My problems comes when I change from P to R or D the transmission or the engine jumps. The strange thing is that their is no check engine light. I already change all the transmission and engine mounts and still doing it. An important point is that it does not always do it. I wanted to know if it can be related to the input/output speed sensors and if yes where those sensors located at?