The old grease in the gear and rack behind the key cylinder is known to get stiff in the cold, making it difficult to turn the key. Some have broken the *** metal parts. The proper fix is to disassemble the parts, clean the grease off and re-**** with thin ****. Things have to be put back just so, so it is not for the average DIYer. However, if you have a tilt column, it is easy to remove the cylinder, spray thin oil back on the gear, which will dilute the stiff grease and keep the key working. If something is not done, you may well break the works.
With a tilt column there is a hole near the base of the cylinder that will allow you to release the cylinder, (non-tilt requires the steering wheel to come off to get to the release hole.) Disconnect the battery. Turn the key to the run position. Mark the column so you can re-install the cylinder in the run position. Now push a pin punch or stiff wire into the release hole and remove the cylinder with the key still in it. The cylinder has a flattened shaft at the back that indexes into a gear, with a rack above it that slides a rod up and down the steering column to work the ignition switch, which is just behind the dash. Remove all the grease you can with a small ***** driver. What you see is not the gear, but rather a washer like bearing that holds the gear in place with a snap ring keeping the parts together. Do not remove the snap ring. Just spray a lot of lite oil over everything and into the hole in the gear. Reinstall the cylinder in the run position and work the key from Start to ACC. repeatedly to work the thin **** into the stiff grease. This is much easier to do than to tell about it. I used SuperLube spray as the thin oil.) My key turns much better but is not as easy as I would like. I will probably do it again next winter.
Hope this helps keep someone from breaking their key workings.
