Car runs fine in park or nuetral. Once shifted into any gear, will shift easily, but then huge knocking and grinding sounds. Sounds continue for a few seconds after put back in park, even when brake and accelerator both not pressed.
Had two people listen to the problem. One said it sounded like the drive shaft, no elaboration. The other said it sounded like the sun gear? Said I probably needed a new transmission, quoted $1200.
Is the car driveable with these noises?
Automatic trannies are rather complex and most times require a pro. My advice would be to take it to the dealer and let them diagnose it for you. Electronically controlled automatics are different from most earlier autos especially Saturns. That is why I recommend the dealer as opposed to a generic tranny shop.
Nothing is ever simple.
Good luck and let us know. : )