When parked and you shift between P to D or R loud engagement of transmission. Thought it was u joints, buddy says both look good/sound good when engaging P D R. Also shifts hard between 1-2-3 intermittently. I did read that it could be the TCC regulator valve?
How many miles? Have you ever changed the trans fluid?
It could be a lot of thing, including just bad motor mounts. I wouldn’t take the wild stab at an internal transmission part, although that’s also possible.
Is you check engine light on?
Have you checked the trans fluid?
Check out the engine/transmission mounts. If all checks out there then I’d probably run it through a reputable transmission shop to have it scanned for codes.