Dual Mass Flywheel

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2007 MINI Cooper, 2006 MINI Cooper, 2005 MINI Cooper, 2004 MINI Cooper, and 2003 MINI Cooper. However, it is still accessible from the selected car via links, so may be relevant.

The MINI Cooper S is fitted with a dual mass flywheel that is attached to the crankshaft by 8 bolts. The flywheel is correctly aligned when the crankshaft center dot is aligned with the scalloped recess on the flywheel. A ring gear is fitted on the outer primary part of the flywheel, and will not be available separately in service. The dual mass flywheel is used to insulate the gearbox from torsional and transient vibrations produced by the engine or driveline. The flywheel consists of a primary and a secondary flywheel.

The drive between the two is transferred by a torsional damper made up of four coil springs located in the inside diameter of the primary flywheel. Two of the springs are of smaller diameter and fit inside the larger diameter springs. The two pairs of coil springs are located in a recess in the flywheel, between two riveted retainers. A roller bearing is pressed onto the central boss of the primary flywheel and is retained with a riveted plate. The bearing provides the mounting for the secondary flywheel.

The secondary flywheel consists of two parts, an outer flywheel, which provides the friction surface for the clutch drive plate, and an inner drive plate, which transfers the drive from the primary flywheel via the coil springs, to the outer flywheel. The two components of the secondary flywheel are secured to each other with rivets. The inner drive plate is located between the two pairs of coil springs and can rotate on the ball bearing in either direction against the combined compression force of the four coil springs. Under high torque loading conditions the secondary flywheel can rotate in either direction up to 70 degrees in relation to the primary flywheel.