Control arms hold front wheels, allowing up and down movement. of the front suspension. The control arm is an important part of the front suspension. It connects the steering knuckle (the part that holds the front wheel) to the vehicle's frame or body, see the photo.
Often, installers use grout in place of caulk for these reasons: 1  The caulk may not exactly match the grout color.  Even when the caulk exactly matches the grout color when installed, it may not match six months later (caulk will age differently from the grout).
What is Grout? According to the Merriam-Webster dictionary: A thin mortar used for filling spaces (as the joints in masonry or ceramic tile); also: any of various other materials (as a mixture of cement and water or chemicals that solidify) used for a similar purpose. A building material (as a mixture of cement, lime, or gypsum plaster with sand and water) that hardens and is used in masonry or ceramic tile.