How does one know if your front shock mounting need replacing?

Upper strut mounts commonly cause a knocking if the holes are rusted out but checking them is almost impossible without removing the strut and disassembly it. Worn mounts are usually found during routine strut replacement.

Worn anti-sway bar links and bushings are more common for making noise. We're also seeing more and more control arm bushings than on older cars. There is a tool you might be able to borrow or rent from an auto parts store that borrows them called the "Chassis Ear". It is a set of six microphones, a switch box, and headphones. You clip the microphones to suspect points, then drive around while listening with the headphones. You can move the microphones around to zero in on the source of the noise. Be aware that many mechanics have never seen or even heard of this tool. Suspension and alignment mechanics use it to find rattles, squeaks, and other noises.