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.
About The Author
Jim Oaks is the founder of The Ranger Station, one of the longest-running Ford Ranger enthusiast communities on the web. He has spent over three decades owning, modifying, repairing, and driving Ford Rangers on the street, trail, and cross-country routes.
Since launching TheRangerStation.com in 1999, Jim has documented thousands of real-world Ranger builds, technical repairs, drivetrain swaps, suspension modifications, and off-road tests contributed by owners worldwide. His work has been referenced by enthusiasts, mechanics, and off-road builders looking for practical, experience-based information rather than theoretical advice.
Jim’s hands-on experience includes long-distance overland travel, trail use, drivetrain and axle upgrades, suspension tuning, and platform comparisons across multiple Ranger generations. The content published on The Ranger Station is grounded in first-hand experience and community-verified data, not marketing claims or generic specifications.