The Chevrolet Tail Light Lens assembly is in place so those vehicles behind you can be aware of not only your presence, but be ready if you decide to slow down or stop your vehicle. The tail light lens assembly is not only a safety device but also required to be in operational statues by law on your Chevrolet.
Under normal circumstances the tail light lens assembly will not just fail on your Chevrolet. This is a polymer component that will dry out over time but for it to breaks a force will have to be applied to it. This force can be an impact with an object or can be when the hold down screws are tightened too much. If either of those occurs to your tail light lens assembly then a crack can be made in it. The crack is how moisture can then enter the assembly which can short out the tail light bulb causing the unit to be faulty and in most counties across the nation rendering the vehicle illegal to be driven on the road.
If a crack is noticed on one or both of your Chevrolet tail light lens assemblies, the entire unit should be pulled from the vehicle and inspected. This is the only way to make sure that not only the front of the assembly is inspected but also the back portion of it that is secured to the vehicle. Cracks in the backing portion and the hold down holes for the screws have to be inspected for damage.
If any section of the tail light lens assembly is damaged on your Chevrolet, it has to be replaced so this unit can be sealed from the elements the outside of the vehicle will encounter.