2004 BMW 645Ci Flywheels and Flexplates

LuK dual-mass flywheels absorb engine vibrations before they are transmitted to the driveline where they can create gear rattle. These units feature a built-in damper designed to isolate engine torque spikes and prevent transmission damage. By design, dual-mass flywheels cannot be resurfaced. This all makes the LuK dual mass flywheel the ideal solution. With one drawback: the higher the mass reactance of the vibrating masses, the more excessive the resonance increase and associated torque peaks. With the dual mass flywheel, this would be easily perceived when starting and stopping the engine; much more easily than with a conventional clutch system. Additionally: the smaller flymass of the engine has less of a stabilizing effect on the speed fluctuation of the engine. Thanks to decades of experience in clutch building, the LuK specialists were able to find an excellent solution to this problem. An additional damping device effectively prevents resonance overload. In normal operation, however, this additional damping device has no function and the torsional vibrations of the engine are filtered out by spring dampers. Friction and spring rate – the correct ratio is important. For optimal vibration isolation and soft resonance passage when starting and stopping the engine, the ratio between friction and spring rate must be optimal. The length of the springs is a key factor: The softer a spring, the more efficiently vibrations are isolated. The extra-long springs of the latest generation of dual mass flywheels significantly reduce the spring rate compared to a first generation dual mass flywheel. In routine driving operations, excessive resonance increases are kept almost completely away from the gearbox.

Product Features:

• Top driving comfort
• Absorbs vibrations
• Prevents noise
• Enables comfortable, low-revs driving
• Saves fuel
• Relieves crankshaft and gearbox

LuK: Don’t gamble – stay with the original LuK DMF! The LuK DMF prevents damages solid flywheels may cause. The LUK Dual Mass Flywheel (DMF) is individually fine-tuned for every type of car. The risks of using solid flywheels are numerous – from increased wear of engine mounts through gearbox failure to damaged crankshafts.