Replace your transmission pump or get a new transmission.
Low transmission fluid, transmission on it's way out.
If your car shakes while accelerating check your motor mounts. Then check your transmission.
It was the starter
The most common cause for a 1996 Mercury Sable not starting is a dead battery. The second most common cause for the automobile not to start is a lack of fuel.
Bad plugs and wires or/and coil
A 1997 Mercury Sable came stock with size p205/65r15 tires. Taller or shorter tires will cause the speedometer to read incorrectly.
The most common cause of a dome light staying on in a Mercury Sable is electrical issues. If a fuse becomes disconnected or is loose this can cause the light to remain on. Check the dimmer switch and the plunger switches in the door jambs.
It is possible if the selector doesn't lock in to position. Also check the transmission fluid level. Low fluid will also be a factor. There could also be other issues that should be looked at by a professional, reliable transmission shop.
AnswerYes, that and more. See "Related Questions" below for extensive coverage of replacing the vehicle speed sensor (VSS), including links to photos.
Lack of or absence of maintenance such as oil changes and fluid levels.