Which of these components is NOT part of a dual mass flywheel?

A dual mass flywheel is specifically designed to improve the performance and comfort of a vehicle by dampening vibrations and accommodating the torque from the engine more effectively. The components that make up a dual mass flywheel include the primary and secondary flywheel, which can move independently of each other; springs that help absorb shocks and vibrations between the two flywheels; and typically grease fittings that ensure smooth operation of the moving parts inside the assembly.

The primary and secondary flywheels are crucial as they allow for relative motion, which helps in balancing engine vibrations. Springs play an important role in absorbing any sudden changes in torque, while grease fittings facilitate lubrication, prolonging the life of the internal components.

In contrast, ball bearings are not a standard part of a dual mass flywheel. This is because the design of a dual mass flywheel relies on its unique construction and spring mechanisms to manage forces, rather than using ball bearings. Therefore, identifying components not involved in the construction or function of a dual mass flywheel helps clarify its operational design.