Changing out my brake pads today. Just finished the fronts with Ferodo pads and the pads come with the shims just like the ones I am swapping out. Go to the rears and removed the old pads and they come with the shims just like the fronts. The problem is when I opened the box of the Mintex pads, they don't come with the shimss Just a naked set of pads.

I can't reuse the old shims because they appear tightly glued. What would happen if I don't use the shims? Is it going to make noise or whatever?