I think my car may need a new transmission.
I would need more information to make a proper diagnosis; you may just have a bad sensor or shift cable, which would be relatively simple and inexpensive to fix, whereas a transmission replacement would be very expensive. I recommend that you have a mechanic, such as one from YourMechanic, come by and inspect your car first, before condemning the transmission assembly.
Have a car question? Get free advice from our top-rated mechanics.