Dual-Mass Flywheel

The dual-mass flywheel (DMF) dampens torsional vibrations between the engine and transmission.

How It Works

Two flywheel masses connected by arc springs. The primary mass bolts to the crankshaft; the secondary mass faces the clutch disc.

Failure Symptoms

• Rattling noise at idle (especially in neutral)
• Vibration when engaging clutch
• Excessive free play when rocking the flywheel by hand
• Difficulty shifting smoothly

Single-Mass Flywheel Conversion

Some owners convert to a single-mass flywheel (SMF) to eliminate the DMF as a wear item.

• Pros: Lower cost, no future DMF failure, lighter weight
• Cons: More drivetrain vibration, harsher engagement, potential transmission wear