Just grease it
Some 2012-2014 Ford Focus vehicles may exhibit a clunk and/or rattle noise from the right and/or left front strut between 5-20 mph over minor road surface imperfections.
The likely cause is a sticking/dry jounce bumper.
1. Raise the vehicle.
2, Reach through the spring and pull the strut dust boot down from the strut bearing.
3. Pull the jounce bumper straight down from the strut bearing.
4. Liberally apply Motorcraft Silicone Brake Caliper Grease and dielectric compound to the length of the strut shaft that contacts the jounce bumper plus ½-inch. Make sure that the lubricant is applied completely around the strut shaft.
5. Lubricate the top of the jounce bumper and position the bumper into the strut bearing.
6. Reposition the dust boot.