Squeaky car radio antennas take a convenient feature and turn it into an annoyance. As you drive, dust and grit in the air will stick to the antenna, making it stick. Like all things that are lubricated, an antenna needs a little maintenance now and then to quiet the squeaks and increase the life of the antenna. This task will only take about 10 minutes of time, and your ears will thank you every time the antenna goes up or down.
Turn on the radio to extend the antenna.
Spray some cleaner/degreaser onto a shop towel and wipe the antenna clean.
Turn off the radio to retract the antenna, then extend the antenna again. If there is still dirt and grease on the antenna after you extend it, repeat the cleaning steps until the antenna extends clean.
Hold a clean shop towel behind the antenna to control overspray.
Spray the antenna lightly with the white lithium grease spray, starting from the bottom and working your way slowly up to the top. Keep the antenna between the spray can and the towel.
Use the shop towel to spread the grease spray over all of the exposed mast.
Retract and extend the antenna several times to make sure that the grease is distributed evenly.
If necessary, spray on a bit more grease until the antenna extends and retracts smoothly and quietly.
Cleaning off the old grease keeps the antenna clean and removes any dust or grit stuck to the grease that could scratch the antenna and shorten its life. Use lint-free shop towels so you aren't leaving behind thread particles that can get embedded in the grease. White lithium grease is preferred, because it won't wash off and works as a corrosion inhibitor to keep the antenna mast in great shape.
Don't use too much cleaner/degreaser on the antenna, and don't spray it directly onto the antenna mast. If the degreaser runs down the inside of the mast, it could get into the housing that holds the antenna and degrade the grease that protects the gears that extend and retract the antenna. Don't spray the cleaner/degreaser in the direction of the car, because some formulations may be harmful to the paint surface.