Technical Service Bulletin
SSM 50432 2011-2021 Various Vehicles – Repeat Spark Plug Replacements
When replacing spark plugs, all spark plug boots should be inspected for signs of arcing or carbon deposits. The boot cannot be cleaned and must be replaced. Failure to do so may result in repeat replacement of the spark plug caused by arcing. Refer to Workshop Manual (WSM) Section, 303-00 (Spark Plug Inspection). For 2018 and older vehicles, refer to 2019 and newer Workshop Manual for Spark Plug Inspection procedure. When installing, refer to the Spark Plug Removal and Installation procedure found in WSM Section, 303-07 to prevent wrench breaking from side loading. A tilted or poorly seated socket can cause tool slip and fracture the ceramic insulator of the spark plug.
Jim Oaks is the founder of TheRangerStation.com, the longest-running Ford Ranger resource online since 1999. With over 25 years of hands-on experience building and modifying Ford Rangers — including magazine-featured builds like Project Transformer — Jim has become one of the most trusted authorities in the Ford Ranger off-road and enthusiast space. In 2019, he was loaned a Ranger FX4 by Ford Motor Company to test and document across the TransAmerica Trail. Jim continues to inspire and guide Ranger owners around the world.