3964636 Belt Tensioner Application: For Cummins B3.9L 4BT 6BT Overview The 3964636 Belt Tensioner is designed for Cummins B3.9L family engines. This package includes a comprehensive set of engine parts to support maintenance, overhaul, or OEM replacement, ensuring proper belt tensioning and alignment within the specified engine models. Included engine parts liner kit liner piston piston ring main bearing connecting rod bearing thrust plate inlet valve exhaust valve valve set valve guide gasket kit plunger delivery valve nozzle cylinder block cylinder head oil pump crankshaft camshaft connecting rod feed pump water pump fan blade turbocharger nozzle piping thermostat engine cushion etc Key benefits Reliable belt tensioning for Cummins B3.9L 4BT and 6BT engines, promoting belt life and smooth operation. OEM aligned compatibility with Cummins B3.9L family engines for straightforward installation. Comprehensive parts inclusion supports complete maintenance or overhaul in a single package. Clear compatibility and scope of components help reduce downtime during service and repairs. Use scenarios Engine overhaul or rebuild on a Cummins B3.9L 4BT or 6BT, when replacing the belt tensioner and related components in one kit. Fleet maintenance for vehicles and equipment powered by Cummins B3.9L engines, enabling planned parts replacement to minimize downtime. Service and of industrial equipment or generators using Cummins B3.9L engines, where a complete set of essential engine parts is required.