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).
Grout is a particularly fluid form of concrete used to fill gaps. Grout is generally a mixture of water, cement, and sand, and is employed in pressure grouting, embedding rebar in masonry walls, connecting sections of pre-cast concrete, filling voids, and sealing joints such as those between tiles.