Cummins 5648746L Flywheel Assembly

The Cummins 5648746L is a precision-machined flywheel assembly designed for 15-liter heavy-duty diesel engines including the ISX, QSX, and Signature 600 series. It serves as the primary inertia mass for engine rotation and provides the friction surface for the clutch assembly. This unit features a 15-inch (381 mm) clutch bore diameter compatible with 7-spring or 10-spring dampened clutch discs. The mounting configuration utilizes six primary bolt holes and two locator dowel holes for precise alignment to the crankshaft flange. The integrated ring gear carries part number 4851 with 153 teeth for starter motor engagement. The pilot bearing bore accepts standard bearing 306 (6306). Constructed from high-strength cast iron (ASTM A48 Class 40 or equivalent) with a hardened steel ring gear shrunk fit. Supersedes previous part numbers 3680878 and 4026222. Dynamic balanced to OEM specifications for vibration control at rated speeds up to 2100 RPM.