* Check your owner's manual: This is the most reliable source.
* Use a socket wrench set: Try different sizes until you find the one that fits. Start with a 32mm, as that's the most probable size. Do not force any socket.
* Consult a repair manual specific to your 1997 Pontiac Grand Am: A Haynes or Chilton manual will give you detailed specifications.
* Visit a local auto parts store: Show them your car and ask for the correct size axle nut. They often have sizing charts.
Always prioritize safety. Improper tools or incorrect sizing can lead to damage.