Dual Mass Flywheel - BMW 1 / 2 / 3 / 4 / 5 / X1 / Z4 Series - Various Models

Dual Mass Flywheel - BMW 1 / 2 / 3 / 4 / 5 / X1 / Z4 Series - Various Models

BMW Part Number: 21 20 7 638 306 / 21 20 7 634 767 / 21 20 7 605 403

Brand: LUK (German O.E.M)

Fitment: Complete

To Fit the following Models:

F20 1-Series 5-Door 125i - All Models

F20 LCI 1-Series 5-Door 125i - N20 - All Models

F21 1-Series 3-Door 125i - All Models

F22 2-Series Coupe 220i - N20 - All Models

F22 2-Series Coupe 228i - All Models

F23 2-Series Cabrio 220i - N20 - All Models

F23 2-Series Cabrio 228i - All Models

F30 3-Series Sedan 320i - All Models

F30 3-Series Sedan 328i - All Models

F34 3-Series Gran Turismo 320i - All Models

F34 3-Series Gran Turismo 328i - All Models

F32 4-Series Coupe 420i - All Models

F32 4-Series Coupe 428i - All Models

F33 4-Series Cabrio 420i - All Models

F33 4-Series Cabrio 428i - All Models

F36 4-Series Gran Coupe 420i - All Models

F36 4-Series Gran Coupe 428i - All Models

F10 5-Series Sedan 520i - All Models

F10 5-Series Sedan 528i - N20 - All Models

F10 LCI 5-Series Sedan 520i - All Models

F10 LCI 5-Series Sedan 528i - All Models

E84 X1-Series 20i sDrive - All Models

E89 Z4-Series Roadster 20i - All Models

E89 Z4-Series Roadster 28i - All Models

A glance at the benefits of the Luk dual mass flywheel

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

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 stabilising 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