Skipping or wiper chatter during windshield wiper operation may be caused by all of these EXCEPT:

• A. Worn splines
• B. Damaged windshield
• C. Dirty blades
• D. Improper mounting

Answer: (A)

Chatter or skipping happens when the blade cannot glide smoothly across the windshield, which is usually due to contact issues rather than the drive mechanism. A windshield with pits, chips, or irregularities will push the blade up or cause it to ride unevenly, producing vibration. Dirty or stiff blades don’t lay flat and may grab and release as they pass, also causing chatter. If the blade isn’t mounted correctly, it won’t press evenly against the glass, leading to skipping. Worn splines, on the other hand, typically affect how the blade is driven (loose drive or erratic movement) rather than causing the windscreen contact to chatter, so they’re not a common cause of this symptom.