I have been a VCR Technician for over 20 years. I most cases it is the Pinch Roller - also known as the Capstan Roller - which is faulty. It is big black hard rubber roller to the right side of the Video Head Drum.
I suggest that you open up the cover of the VCR, and then observe what happens when the Tape is played. observe what is happening.
It might require that you may have to replace the Roller.
Otherwise, can you share a small video of the process - 10 to 15 seconds - with the cover removed ?