Engine Torque Specifications
dry installation (Gasket Type Spark Plugs)

Spark Plug Thread Size 14MM 18MM 7/8”-18 Caterpillar 3600 engines Cast Iron Heads 26-30 lb-ft 32-38 lb-ft 50-55 lb-ft 47-52 lb-ft Aluminum Heads 18-22 lb-ft 28-34 lb-ft — — Note: If threads are lubricated, reduce torque value by 20%