A muffler assembly includes an outer shell defining an internal cavity that extends between first and second ends. A first end cap is attached to the first end and a second end cap is attached to the second end. The first and second end caps provide a substantially enclosed internal cavity within the outer shell. A heat shield extends along a length of the outer shell and has a first shield end attached to the first end cap and a second shield end attached to the second end cap. The first and second shield ends are deformed around an outer perimeter of the first and second ends caps, or separate retaining members are used to secure the first and second shield ends to the first and second end caps.