Sometimes, replacing the wiper blade on your windshield wiper just isn't enough if the wiper arm has been compromised, bent, damaged or misaligned by ice, snow or any other foreign object. In this case, replacing the arm is a simple process that you can do yourself, saving you money in the process,
Determine whether or not the application of your vehicle would simplify the removal of the arm to open the hood. There are some applications in which this is not necessary. Also, inspect the wiper arm and determine whether or not windshield-washer rubber plumbing lines are attached. If they are, simply unsnap the connector of the sprayer device and unclip the line from underneath the arm and let it dangle to the side, but out of the way. A telltale sign there are no windshield washer-lines is found at the point of exit for the spray. Many cars have sprayers attached to the hood and not to the wiper blades.
Locate the bottom of the wiper arm. There is a snap-down cover at the bottom of most common wiper arms. Open this cover with the quick flick of a flat-headed screwdriver or a small angled pry bar.
Notice the nut beneath the cover. The size of this nut will vary depending on the vehicle application. Some common sizes are 13mm or 14mm for import vehicles and 9/16 inch or 5/8 inch on domestic vehicles. However, have a variety of sockets on hand, in case a different size is used. Holding the wiper arm with one hand, loosen the nut and remove it with a ratchet and appropriate socket.
Place a thick cloth, rag or padding between the wiper blade and arm area and the windshield to prevent windshield damage. Using the pry bar or screwdriver, pry the wiper arm off the splined spindle from which the nut was just extracted. This is sometimes a tricky process. It may not feel like the arm wants to come off the spindle, and you will need to balance applied pressure and tenacity without incurring damage to the vehicle or windshield.
Remove the padding or cloth, but be very careful with the delicate surface of the windshield. Replace the old arm with the new one, making sure you are putting it on in the same manner in which it was removed. If the wiper arm was in the "off" position, make sure you're replacing it in that same position. The splines on the spindle will limit how much you will able to move the arm once it's back on, so aligning it to the correct position will dictate how well aligned the wiper arm is when in operation.
Replace and tighten the spindle nut with the ratchet, as tight as you can get it without over-tightening. Close the snap-down cover and replace the windshield-washer rubber lines (if applicable). Test the wiper arm and sprayer to make sure it is operating to specifications.
