Faulty wipers in use can cause a variety of symptoms, including smears, uneven wiping, and lifting at high speeds. After removing one end-cap, the metal-backed rubber wiper blade can be slid into its holder. Replace the cap at all times. An alternative method is to secure the assembly arm to the arm. In either case, ensure that the blade is securely in place. Splines are typically used to locate the wiper arm on its spindle. Before removing the old one, make sure it’s in the right place.